https://DevOpsCloud.io -- Cloud Monk Losang Jinpa, Ph.D., MCSE/MCT, GitOps DevOps Engineer

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Time to First Byte (TTFB) measures the time from when a user makes an HTTP request to when the first byte of the response is received by the browser. It includes network latency, server processing time, and the time taken to deliver the first byte of data. Improving TTFB is crucial for web performance as it impacts how quickly the browser can start rendering the page. https://en.wikipedia.org/wiki/Time_to_first_byte

Content Delivery Network (CDN) is a geographically distributed network of servers that cache content close to users, reducing latency and improving load times. CDNs improve web performance by delivering static assets like images, stylesheets, and scripts from servers that are physically closer to the end-user. https://en.wikipedia.org/wiki/Content_delivery_network

First Contentful Paint (FCP) measures the time from when the page starts loading to when any part of the page's content is first rendered. This metric helps understand how quickly users perceive content being displayed on the screen, making it a key indicator of web performance. https://web.dev/fcp/

Largest Contentful Paint (LCP) is a web performance metric that reports the render time of the largest visible element in the viewport. It is part of Core Web Vitals and indicates when the main content of a web page has likely loaded, affecting user experience. https://web.dev/lcp/

Cumulative Layout Shift (CLS) measures the visual stability of a webpage by tracking unexpected layout shifts during page loading. High CLS scores indicate poor user experience as elements move around unexpectedly, disrupting interaction. Optimizing CSS and image dimensions reduces layout shifts. https://web.dev/cls/

First Input Delay (FID) is a web performance metric that measures the time from when a user first interacts with a page to when the browser responds to that interaction. Improving FID helps reduce user-perceived latency, contributing to a smoother and more responsive interface. https://web.dev/fid/

Lazy Loading is a web optimization technique that delays the loading of non-critical resources (like images or videos) until they are needed, reducing initial load time and saving bandwidth. Implementing lazy loading improves performance for resource-heavy pages by only loading assets when they enter the viewport. https://developer.mozilla.org/en-US/docs/Web/Performance/Lazy_loading

Compression refers to reducing the size of web assets (HTML, CSS, JavaScript) before sending them over the network. Using algorithms like Gzip or Brotli helps improve performance by reducing download times, especially for users with slow internet connections. https://developer.mozilla.org/en-US/docs/Web/HTTP/Compression

Minification is the process of removing unnecessary characters (like whitespace, comments, and line breaks) from code without affecting functionality. Minifying CSS, JavaScript, and HTML reduces file sizes and improves web performance by reducing the amount of data that needs to be transferred. https://en.wikipedia.org/wiki/Minification_(programming)

HTTP/2 is a major revision of the HTTP network protocol designed to improve web performance. HTTP/2 introduces features like multiplexing, header compression, and server push, which reduce latency and improve loading times compared to HTTP/1.1. https://en.wikipedia.org/wiki/HTTP/2

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Render-Blocking Resources are CSS or JavaScript files that prevent the browser from rendering content until they are fully loaded. Optimizing or deferring these resources improves web performance by reducing the time it takes for the page to become interactive. Techniques like inlining critical CSS or using async for scripts can help. https://developer.mozilla.org/en-US/docs/Web/Performance/Understanding_resource_loading

Cache-Control Headers are HTTP headers used to specify caching policies for both the browser and intermediary caches. Properly configuring Cache-Control headers ensures that frequently accessed resources are cached and reduces server load, improving performance for repeat visitors. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control

DNS Lookup Time measures how long it takes to resolve a domain name into its corresponding IP address. Reducing DNS lookup time by optimizing DNS servers or using a DNS caching service improves the time to load a web page, especially for first-time visitors. https://en.wikipedia.org/wiki/Domain_Name_System

Preload is a web performance technique that instructs the browser to fetch critical resources (such as fonts or images) early, even before they are needed. Using preload for important assets reduces load times by ensuring they are available as soon as they are required by the page. https://developer.mozilla.org/en-US/docs/Web/HTML/Preloading_content

Resource Hints are HTML attributes and HTTP headers that provide the browser with instructions about which resources to prioritize. Examples include preconnect, prefetch, and dns-prefetch, which help reduce round-trip times and improve web performance by optimizing resource loading. https://developer.mozilla.org/en-US/docs/Web/Performance/dns-prefetch

Critical Rendering Path refers to the sequence of steps that the browser takes to convert HTML, CSS, and JavaScript into pixels on the screen. Optimizing the critical rendering path by minimizing the number of resources or reducing their size helps reduce page load times and improves user experience. https://developers.google.com/web/fundamentals/performance/critical-rendering-path

Connection Keep-Alive is an HTTP feature that allows the same TCP connection to be used for multiple HTTP requests/responses, reducing the overhead of establishing new connections. Enabling Keep-Alive on servers improves web performance by reducing latency and server load. https://en.wikipedia.org/wiki/HTTP_persistent_connection

Viewport Meta Tag is an HTML element that helps control the layout on mobile devices by instructing the browser how to adjust the page's dimensions and scaling. Properly configuring the viewport meta tag improves performance and ensures that pages render well on different devices. https://developer.mozilla.org/en-US/docs/Web/HTML/Viewport_meta_tag

Service Workers are scripts that run in the background, independent of web pages, to manage caching and enable offline access. Service workers improve performance by intercepting network requests and serving cached assets, allowing faster load times and functionality even without an active network connection. https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API

HTTP/3 is the latest version of the HTTP protocol, built on top of QUIC (a transport layer network protocol). HTTP/3 improves web performance by reducing latency, speeding up connection establishment, and handling packet loss more effectively than HTTP/2, especially in unreliable network conditions. https://en.wikipedia.org/wiki/HTTP/3

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Lazy Loading Images is a performance optimization technique that defers loading images until they are needed, typically when they appear in the viewport. This reduces initial page load times and bandwidth consumption, improving overall web performance, especially for image-heavy pages. https://developer.mozilla.org/en-US/docs/Web/Performance/Lazy_loading

HTTP Caching refers to the process of storing copies of resources locally on the client’s browser or at intermediary locations to reduce server requests. Effective HTTP caching improves web performance by loading resources from cache instead of fetching them over the network, significantly speeding up subsequent page loads. https://developer.mozilla.org/en-US/docs/Web/HTTP/Caching

Font Display Swap is a CSS feature that controls how web fonts are displayed during their loading phase. By using the swap property, text is rendered using a fallback font until the custom font is loaded, preventing invisible text and improving perceived performance. https://developer.mozilla.org/en-US/docs/Web/CSS/@font-face/font-display

Deferred JavaScript allows scripts to be executed after the HTML document has been completely parsed. Using defer for non-essential scripts reduces render-blocking behavior and improves page load performance by allowing content to be displayed faster. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script

Asynchronous JavaScript execution, enabled by the async attribute, allows JavaScript files to be loaded and executed asynchronously, without blocking the parsing of HTML. This reduces the time it takes for the page to become interactive, enhancing performance, especially for large JavaScript files. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script

Connection Pooling refers to reusing existing connections instead of opening new ones for every HTTP request. In Go web servers and other systems, connection pooling reduces latency and system resource usage, improving response times and web server performance. https://en.wikipedia.org/wiki/Connection_pool

Content Security Policy (CSP) is a web security feature that helps prevent cross-site scripting (XSS) attacks by specifying which resources are allowed to load. A properly configured CSP can also improve performance by blocking unwanted external scripts or assets from being loaded, thus reducing unnecessary resource usage. https://developer.mozilla.org/en-US/docs/Web/HTTP/CSP

Server Push is a feature of HTTP/2 that allows the server to send resources to the client before the client explicitly requests them. This can improve web performance by reducing the number of round-trips needed to load a page, especially for resources that the server knows the client will need. https://developer.mozilla.org/en-US/docs/Web/HTTP/Server_push

Image Compression reduces the file size of images without significantly compromising quality. Using lossless or lossy compression algorithms for images improves page load times and reduces bandwidth usage, which is critical for optimizing web performance, especially on mobile networks. https://en.wikipedia.org/wiki/Image_compression

DOMContentLoaded Event is triggered when the initial HTML document has been completely loaded and parsed, without waiting for stylesheets, images, and subframes to finish loading. Optimizing the time to DOMContentLoaded ensures faster page rendering and quicker interactivity for users. https://developer.mozilla.org/en-US/docs/Web/API/Document/DOMContentLoaded_event

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Prefetching is a technique that involves loading resources before they are needed, typically in the background. By using prefetch for assets like scripts or images that will be required on future pages, web performance is improved by reducing load times for subsequent user interactions. https://developer.mozilla.org/en-US/docs/Web/HTTP/Link_prefetching_FAQ

Adaptive Bitrate Streaming is a method used in video streaming that adjusts the quality of the video in real-time based on the user's network conditions. This improves performance by ensuring smooth playback without buffering, even on slower connections. https://en.wikipedia.org/wiki/Adaptive_bitrate_streaming

TCP Slow Start is a feature of the TCP protocol that controls the rate at which data is sent over a network connection to avoid congestion. Optimizing for TCP slow start can improve initial connection times and overall web performance, especially in environments with high latency. https://en.wikipedia.org/wiki/TCP_congestion_control#Slow_start

Resource Timing API is a web performance API that allows developers to collect high-resolution timing data about resources fetched for a page. Using the Resource Timing API helps identify performance bottlenecks by providing detailed insights into how long each resource takes to load. https://developer.mozilla.org/en-US/docs/Web/API/Resource_Timing_API

Viewport Units are CSS units relative to the size of the viewport, like vh (viewport height) and vw (viewport width). Proper use of viewport units ensures responsive design, improving performance by reducing the need for complex media queries and recalculations during page resize events. https://developer.mozilla.org/en-US/docs/Web/CSS/length

Critical CSS refers to the minimum set of CSS required to render the initial viewport of a page. Extracting and inlining critical CSS reduces render-blocking resources, helping the page render faster and improving performance, especially on slower connections. https://developers.google.com/web/tools/lighthouse/audits/blocking-resources

Service Worker Cache API allows service workers to cache network requests and serve them from the cache, improving performance by reducing the number of network requests needed. By storing static assets locally, pages can load faster and provide offline functionality. https://developer.mozilla.org/en-US/docs/Web/API/Cache

Progressive Web Apps (PWA) are web applications that offer a native app-like experience through features like offline access, push notifications, and fast load times. PWAs improve performance by caching resources, enabling quicker access to content and reducing the need for repeated network requests. https://en.wikipedia.org/wiki/Progressive_web_application

Intersection Observer API is a web API that allows developers to efficiently observe changes in the intersection of a target element with a parent or viewport. By using the Intersection Observer API for lazy loading or analytics, unnecessary DOM updates are minimized, improving performance. https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API

WebSocket is a communication protocol that provides full-duplex communication over a single, long-lived connection. In Go or other environments, using WebSockets can improve performance for real-time applications like chat or live updates by reducing the overhead of repeated HTTP requests. https://en.wikipedia.org/wiki/WebSocket

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HTTP Keep-Alive is a feature that allows a single TCP connection to remain open for multiple HTTP requests and responses, reducing the overhead of creating new connections for each request. Enabling HTTP Keep-Alive improves web performance by reducing latency and server load, especially for pages with many assets. https://en.wikipedia.org/wiki/HTTP_persistent_connection

Script Defer is an attribute that ensures a script is executed only after the HTML document has been completely parsed. Using defer for non-essential scripts improves performance by allowing the page to render more quickly without being blocked by JavaScript execution. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script

CDN Edge Servers are geographically distributed servers that cache content close to the user, reducing latency. By leveraging CDN edge servers, web performance is improved by minimizing the distance between the user and the server, allowing faster delivery of static and dynamic content. https://en.wikipedia.org/wiki/Content_delivery_network

Connection Reuse refers to reusing existing network connections for multiple requests instead of establishing new connections. In web development, connection reuse improves performance by reducing the time and overhead associated with setting up new connections, particularly for HTTP/1.x requests. https://en.wikipedia.org/wiki/HTTP_persistent_connection

TCP Handshake is the process of establishing a connection between a client and a server before data transmission. Optimizing the TCP handshake (e.g., by using TCP Fast Open) reduces the time required to establish connections, improving overall web performance, especially for first-time visitors. https://en.wikipedia.org/wiki/Transmission_Control_Protocol#Connection_establishment

Preconnect is a resource hint that informs the browser to establish early connections to important third-party origins (e.g., CDNs) before any actual resource requests are made. Using preconnect improves web performance by reducing latency for critical resources. https://developer.mozilla.org/en-US/docs/Web/Performance/dns-prefetch

Image Sprites are a performance optimization technique where multiple small images are combined into a single file to reduce the number of HTTP requests. Using image sprites reduces server load and speeds up page rendering, particularly in environments where many small images are used. https://en.wikipedia.org/wiki/Sprite_(computer_graphics)

HTTP Compression refers to compressing HTTP responses using algorithms like Gzip or Brotli to reduce file size and improve transmission speed. Implementing HTTP compression reduces bandwidth usage and improves performance, particularly for large HTML, CSS, and JavaScript files. https://developer.mozilla.org/en-US/docs/Web/HTTP/Compression

Priority Hints are used to signal the importance of resources, allowing the browser to prioritize loading them accordingly. By setting priority hints on key resources, developers can improve the perceived performance of a web page by ensuring that important elements load first. https://developer.mozilla.org/en-US/docs/Web/API/Priority_Hints_API

Shadow DOM is a web component technology that allows for encapsulated DOM and CSS, preventing styles and scripts from affecting other parts of the document. Shadow DOM can improve performance by reducing style recalculation and repaint times, especially in large, complex applications. https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_shadow_DOM

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HTTP/2 Multiplexing is a feature of HTTP/2 that allows multiple requests and responses to be sent over a single connection without blocking each other. This improves web performance by reducing latency and eliminating the head-of-line blocking issue present in HTTP/1.1. https://en.wikipedia.org/wiki/HTTP/2#Multiplexing

Content-Security Policy (CSP) Preload is a security mechanism that, when properly configured, allows certain assets to be loaded before others, improving both security and performance. Using CSP preload ensures that critical resources are loaded quickly while enforcing security constraints. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy

Lazy Loading Iframes is an optimization technique where iframes are loaded only when they come into the viewport. This improves performance by deferring the loading of embedded content until it's actually needed, reducing initial page load times. https://developer.mozilla.org/en-US/docs/Web/Performance/Lazy_loading

Critical Path Rendering Optimization involves reducing the number of render-blocking resources that must be processed before a page can be painted on the screen. By minimizing render-blocking resources, such as CSS or JavaScript, the critical path becomes shorter, leading to faster page rendering. https://developers.google.com/web/fundamentals/performance/critical-rendering-path

HTTP/3 QUIC Protocol is a new web transport protocol designed to improve performance by reducing latency, particularly in unreliable network conditions. HTTP/3 uses QUIC to provide faster connection establishment and better performance in comparison to TCP and HTTP/2. https://en.wikipedia.org/wiki/HTTP/3

Resource Preloading is a technique that allows critical resources to be downloaded early in the page load process. By using the preload attribute on important assets, such as fonts or scripts, resource preloading improves web performance by ensuring these assets are available as soon as needed. https://developer.mozilla.org/en-US/docs/Web/HTML/Preloading_content

Font Subsetting refers to including only the necessary characters from a font file, rather than the entire font. Implementing font subsetting reduces the size of font files and improves load times, particularly when large fonts or multiple languages are used. https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/webfont-optimization

Server Timing API allows developers to collect detailed metrics on how long specific server operations took. The Server Timing API helps optimize server-side performance by identifying bottlenecks in the backend, improving the overall user experience. https://developer.mozilla.org/en-US/docs/Web/API/Server-Timing

Cache Busting is a technique used to force the browser to load updated assets instead of serving them from cache. By using cache busting methods like appending version numbers to filenames, developers can ensure users always receive the latest version of resources, improving the freshness of content. https://en.wikipedia.org/wiki/Cache_busting

HTML Parsing Optimization refers to minimizing the complexity of the DOM tree so that the browser can parse and render the page faster. Techniques like simplifying the DOM structure and reducing unnecessary HTML tags improve parsing performance, leading to faster page loads. https://developer.mozilla.org/en-US/docs/Web/HTML

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Edge Computing refers to processing data closer to the user or data source, reducing latency and improving performance. In web performance, edge computing allows for faster data processing and response times by offloading tasks to CDN edge nodes or local servers instead of relying on a central server. https://en.wikipedia.org/wiki/Edge_computing

Image Lazy Loading with srcset is a technique where different versions of an image are provided for different screen resolutions, and the browser picks the most appropriate one. Combined with lazy loading, this reduces the overall load time by delivering only the necessary image sizes when required. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-srcset

Asset Fingerprinting involves appending a unique identifier (often a hash) to filenames of static assets like CSS or JavaScript files. This technique ensures that updated assets are fetched by the browser instead of being served from the cache, improving web performance by ensuring up-to-date resources are used. https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching

Intersection Observers for Infinite Scrolling use the Intersection Observer API to efficiently handle infinite scrolling, loading new content only when the user reaches the end of the page. This improves performance by reducing the initial load time and only loading additional content when necessary. https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API

WebAssembly (Wasm) is a low-level binary format that allows code written in languages other than JavaScript to run in the browser with near-native performance. Using WebAssembly improves performance for computationally expensive tasks such as image processing, video editing, and complex calculations. https://en.wikipedia.org/wiki/WebAssembly

Async CSS Loading involves using the media attribute or rel="preload" to defer loading of non-critical CSS files until after the page has started rendering. This improves page load times by ensuring that essential CSS is applied first, without blocking the rendering of the page. https://developer.mozilla.org/en-US/docs/Web/HTML/Preloading_content

JSON-LD for Structured Data is a method of encoding linked data in JSON format. Using JSON-LD for structured data improves search engine optimization (SEO) and helps search engines understand the content of a webpage more efficiently, enhancing performance in search rankings. https://en.wikipedia.org/wiki/JSON-LD

Progressive Image Rendering is a technique where images are displayed in progressively higher resolutions as they load, rather than waiting for the entire image to download. This gives users the perception of faster loading times, improving perceived performance on image-heavy websites. https://developer.mozilla.org/en-US/docs/Web/Performance/Lazy_loading

Viewport-Optimized Images use the sizes attribute in combination with srcset to ensure that the browser only loads images appropriate for the current viewport size. This reduces the amount of data transferred, particularly on mobile devices, and improves web performance by delivering optimized images. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-sizes

Content Delivery Network (CDN) Compression involves using a CDN that applies compression algorithms such as Brotli or Gzip to resources before delivering them to users. This improves performance by reducing the size of the resources, leading to faster downloads and reduced bandwidth usage. https://developer.mozilla.org/en-US/docs/Web/HTTP/Compression

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Service Worker Caching Strategies are methods used by service workers to control how and when resources are cached. Examples include cache-first, network-first, and stale-while-revalidate strategies. Properly implementing these strategies improves performance by reducing reliance on the network and serving cached content quickly. https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API/Using_Service_Workers

HTTP Range Requests allow clients to request specific portions of a file instead of downloading the entire file. This is particularly useful for large media files, enabling faster access to specific parts of the file and improving performance by reducing unnecessary data transfer. https://en.wikipedia.org/wiki/Byte_serving

HTTP/2 Server Push is a feature that allows a server to send multiple resources to the client without waiting for them to be explicitly requested. By using HTTP/2 Server Push, critical resources can be preemptively sent to the browser, reducing load times by eliminating the need for multiple round-trip requests. https://en.wikipedia.org/wiki/HTTP/2_Server_Push

Progressive Enhancement is a web development strategy that focuses on delivering a basic but functional experience for all users, while enabling richer features for users with better bandwidth or browser capabilities. This approach improves performance by ensuring essential content is available quickly, even on slower networks or devices. https://en.wikipedia.org/wiki/Progressive_enhancement

Viewport-Specific Caching refers to caching different versions of content based on the user’s device viewport (e.g., mobile, tablet, desktop). Using viewport-specific caching optimizes resource delivery by serving tailored content, improving performance by avoiding unnecessary downloads of high-resolution images or large files. https://web.dev/cache-apis-quick-guide/

Resource Prioritization is a technique used to ensure that critical resources like above-the-fold content, CSS, and essential JavaScript are downloaded and executed before less critical assets. This reduces the time it takes for the page to become interactive and improves overall performance. https://developer.mozilla.org/en-US/docs/Web/Performance/Resource_prioritization

Client-Side Rendering (CSR) refers to the process where the browser renders the entire HTML structure of a page using JavaScript. Optimizing client-side rendering in single-page applications (SPAs) can improve perceived performance by allowing users to interact with the page faster while content is loaded dynamically. https://en.wikipedia.org/wiki/Single-page_application

Server-Side Rendering (SSR) generates the complete HTML for a webpage on the server before sending it to the client. SSR improves performance, particularly for initial page loads, as the browser can display content faster without waiting for JavaScript to execute. It also improves SEO by providing search engines with fully rendered HTML. https://en.wikipedia.org/wiki/Server-side_scripting

Asynchronous Data Fetching involves using APIs like fetch or XMLHttpRequest to retrieve data without blocking the rendering of a page. By fetching non-essential data asynchronously, web performance is improved as the browser can continue rendering visible content while the rest of the data is fetched in the background. https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API

DOM Event Delegation is a technique that involves using a single event listener for multiple child elements instead of attaching individual listeners to each element. By optimizing DOM event delegation, web performance improves as fewer event listeners need to be registered, reducing memory usage and improving event handling efficiency. https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Building_blocks/Events

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Resource Sharding is a performance optimization technique that involves splitting resources across multiple domains or subdomains to bypass browser limitations on concurrent connections. By utilizing resource sharding, web performance improves as the browser can download more resources simultaneously, reducing overall load times. https://en.wikipedia.org/wiki/Domain_sharding

Critical Path CSS refers to the minimal amount of CSS needed to render the visible portion of the page. By inlining the critical path CSS directly in the HTML and deferring non-essential CSS, web performance is enhanced as pages can render content more quickly without waiting for external stylesheets to load. https://developers.google.com/web/fundamentals/performance/critical-rendering-path

Lazy Loading Scripts defers the execution of non-essential JavaScript until after the main content of the page is rendered. By using async or defer attributes, lazy loading scripts improves performance by reducing render-blocking resources and allowing content to load faster. https://developer.mozilla.org/en-US/docs/Web/Performance/Lazy_loading

Connection Throttling involves limiting the rate of data transfer in order to reduce the load on servers and networks. In performance testing environments, connection throttling simulates slower network speeds to evaluate how web pages perform under constrained conditions, allowing for more robust optimization. https://en.wikipedia.org/wiki/Traffic_shaping

IndexedDB Caching allows large amounts of structured data to be stored locally within the browser. By caching data using IndexedDB, web performance improves as large datasets, like user preferences or offline resources, can be quickly retrieved from the local database without frequent network requests. https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API

Inline Critical Fonts is a technique where the essential parts of a web font are embedded directly into the HTML or CSS. Inlining critical fonts reduces the time users wait for text to be displayed, improving the perceived performance by preventing FOIT (flash of invisible text). https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/webfont-optimization

Memory Optimization in JavaScript refers to techniques like reducing object allocations, avoiding memory leaks, and cleaning up unused variables. In Go or web environments, efficient memory optimization improves performance by preventing excessive garbage collection and reducing application slowdowns over time. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Memory_Management

Push Notifications allow web applications to send messages directly to the user’s device, even when the website is not open. Implementing efficient push notification systems using service workers can improve user engagement while minimizing performance overhead, as notifications are lightweight and use minimal network resources. https://developer.mozilla.org/en-US/docs/Web/API/Push_API

Prefetch DNS is a technique that performs DNS lookups for external domains before a user navigates to a link. By using dns-prefetch, websites reduce the time taken to resolve DNS queries, improving performance for users clicking through to linked pages on different domains. https://developer.mozilla.org/en-US/docs/Web/Performance/dns-prefetch

Viewport-Specific Media Queries are CSS queries that apply different styles based on the user's device characteristics, such as screen width or orientation. By optimizing content with viewport-specific media queries, web performance improves, especially on mobile devices, by loading only the styles necessary for the current viewport. https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queries

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HTTP Prefetch is a technique that allows browsers to fetch resources before they are needed, often while the user is idle. By using HTTP prefetch, resources like images, scripts, or stylesheets are downloaded in advance, improving the performance of subsequent page loads by reducing perceived latency. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Link#prefetch

Lazy Loading Videos is a technique similar to lazy loading images, where videos are only loaded when they are about to be viewed by the user. Implementing lazy loading videos improves performance by reducing the amount of data initially loaded, saving bandwidth and speeding up page load times. https://developer.mozilla.org/en-US/docs/Web/Performance/Lazy_loading

Content Inlining is the process of embedding small CSS or JavaScript files directly into the HTML document. By inlining content, critical resources are available immediately without additional HTTP requests, improving the time to first paint and overall page load speed. https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/inline-small-css

Priority Resource Loading is an optimization technique where critical resources such as CSS, JavaScript, and images are given higher loading priority. Implementing priority resource loading ensures that essential content is downloaded first, reducing the time it takes for the page to become interactive. https://developer.mozilla.org/en-US/docs/Web/Performance/Resource_prioritization

Cache Partitioning is a browser feature that isolates cached resources based on the requesting site’s origin. Cache partitioning improves both security and performance by preventing shared resources across different sites from affecting load times or exposing vulnerabilities. https://developer.mozilla.org/en-US/docs/Web/Privacy/Partitioned_caches

Service Worker Offline Caching enables a website to cache resources and serve them even when the user is offline. Using service worker offline caching improves the performance and user experience of progressive web apps (PWAs) by ensuring that important assets remain accessible regardless of the network connection. https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API/Using_Service_Workers

Prewarm Connections refers to establishing network connections in advance to reduce the time required for requests. Prewarming connections helps to eliminate the latency that would otherwise occur during the connection handshake phase, improving the time to first byte (TTFB) for critical resources. https://developer.mozilla.org/en-US/docs/Web/Performance/Resource_prioritization#preconnect

CSS Containment is a CSS feature that isolates styles, layout, or rendering of a portion of the DOM from the rest of the page. Implementing CSS containment improves performance by reducing the scope of style recalculations and layout reflows, which can be computationally expensive. https://developer.mozilla.org/en-US/docs/Web/CSS/contain

Lazy Loading CSS is an optimization technique that defers the loading of non-critical CSS files until after the page has been rendered. By lazy loading CSS, non-essential stylesheets do not block the rendering of visible content, speeding up page load times. https://developers.google.com/web/fundamentals/performance/critical-rendering-path

HTTP Retry-After Header is used by servers to indicate how long a client should wait before making a follow-up request after receiving a 503 (Service Unavailable) response. Proper use of the HTTP Retry-After header helps manage server load and maintain performance during peak traffic or scheduled maintenance. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Retry-After

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Network Prioritization involves assigning higher priority to critical resources like CSS or JavaScript to ensure they are downloaded first. By implementing network prioritization, essential content is delivered faster, reducing time to interactivity and improving overall page load performance. https://developer.mozilla.org/en-US/docs/Web/Performance/Resource_prioritization

Client Hints are HTTP request headers that allow the server to tailor content based on user device characteristics, like screen resolution or network speed. Using client hints improves performance by enabling the server to send optimized resources, such as smaller images, based on the user’s environment. https://developer.mozilla.org/en-US/docs/Web/HTTP/Client_hints

Adaptive Images dynamically deliver images tailored to the user’s device and connection speed. By using adaptive images, web performance improves by reducing unnecessary bandwidth usage, especially for mobile users or those with slow internet connections, ensuring images load faster. https://developer.mozilla.org/en-US/docs/Web/Performance/Optimizing_images

Shadow DOM Performance focuses on using Shadow DOM to encapsulate and isolate components, reducing global style recalculations. Leveraging Shadow DOM helps improve performance by preventing style and layout changes from affecting other elements on the page. https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_shadow_DOM

Time to Interactive (TTI) is a web performance metric that measures how long it takes for a page to become fully interactive, meaning users can interact with the page without delay. Improving TTI is crucial for user experience, as a faster TTI ensures the page is usable as soon as possible. https://web.dev/interactive/

Gzip Compression is a widely used method to compress files sent from the server to the browser. Enabling Gzip compression for text-based resources like HTML, CSS, and JavaScript improves performance by reducing the amount of data that needs to be transferred, leading to faster load times. https://en.wikipedia.org/wiki/Gzip

Link Preload is a feature that allows web developers to specify resources that should be loaded early. By using link preload, critical assets like fonts or scripts are downloaded sooner, improving performance by reducing the time it takes for key resources to be available. https://developer.mozilla.org/en-US/docs/Web/HTML/Preloading_content

Long Task API is a browser API that helps identify tasks that take a long time to complete, causing performance issues like jank. By monitoring long tasks, developers can optimize heavy operations to improve web performance and provide a smoother user experience. https://developer.mozilla.org/en-US/docs/Web/API/Long_Tasks_API

Web Workers allow developers to run JavaScript in background threads separate from the main browser thread. Using web workers improves performance by offloading computationally expensive tasks, such as data processing or heavy calculations, without blocking the user interface. https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API

Font Loading API gives developers control over how web fonts are loaded and displayed. The Font Loading API helps optimize web performance by allowing developers to manage font loading behavior, reducing FOIT (flash of invisible text) and improving perceived performance. https://developer.mozilla.org/en-US/docs/Web/API/FontFace

Fair Use Sources:

• B08J5QZPNC (SysPrfBGrg 2021)

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GPT4o:

AbortController, Absolute URLs, Abstract Equality Comparison, Abstract Syntax Tree, Accessor Properties, ActiveXObject, AddEventListener Method, AJAX Calls, AJAX Polling, Alert Dialogs, Alignment of Elements, All Settled Method in Promises, Animation Frames, Anonymous Functions, API Fetching, Application Cache, Arguments Object, Arrow Functions, Art Direction in Web Design, Asynchronous Iterators, Asynchronous Programming, Async Functions, Attribute Nodes, AudioContext API, Augmented Reality in Web, Authentication Tokens, Automatic Semicolon Insertion, Autoplay Attribute, Await Expression, Backbone of JavaScript Applications, Background Scripts, Backwards Compatibility in JavaScript, Base64 Encoding, Beforeunload Event, Best Practices in JavaScript, Binary Data Handling, Binary Heap in JavaScript, Binding of Functions, Blob Objects, Block-Level Scope, Boolean Objects, Bounding Client Rect, Box Model in CSS, Break and Continue Statements, Broadcast Channels, Browser Compatibility, 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getElementsByClassName Method, getElementsByTagName Method, Global Execution Context, Global Object, Global Scope, GlobalThis Object, Grammar and Types in JavaScript, Grid Layout in CSS, GroupBy Functionality, Hash Tables in JavaScript, History API, Hoisting in JavaScript, Horizontal Rule Element, HTML Canvas Element, HTML Collection, HTML Templates, HTML5 Features, HTTP Requests, HTTP Response Codes, Hyperlinks in HTML, IIFE (Immediately Invoked Function Expression), Image Manipulation in Canvas, Image Preloading Techniques, Import Statements, In Operator, Indexed Collections, IndexedDB API, Infinity Value, Inheritance Patterns, Input Events, Input Validation, Instanceof Operator, Int32Array, Intl Object, Intersection Observer API, Intl.Collator, Intl.DateTimeFormat, Intl.NumberFormat, Invalid Date Object, IsNaN Function, Iteration Protocols, JavaScript Engines, JavaScript Modules, JavaScript Object Notation (JSON), JavaScript Operators, JavaScript Regular Expressions, JavaScript Timers, Joystick Events, JSON Methods, JSON Parse and Stringify, Keydown Event, Keyboard Events, Keyframes in CSS, Label Element in Forms, Language Chains in Testing, let Keyword, Lexical Environment, Lexical Scoping, Light DOM, Line Breaks in Strings, Linear Gradient in CSS, Link Element in HTML, Local Storage, Location Object, Logical AND Operator, Logical NOT Operator, Logical OR Operator, Loops in JavaScript, Map Object in JavaScript, Map Method in Arrays, Math Object, Media Queries in CSS, MediaRecorder API, Memory Leaks in JavaScript, Message Channels, Message Event, Meta Tags in HTML, Method Chaining, MIDI Access, Mime Types, Modals in Web Design, Module Bundlers, Mouse Events, MouseEvent Object, Mutation Observers, Named Function Expressions, Namespace Objects, Native Objects in JavaScript, Navigator Object, Nested Functions, New Operator, Node Interface, NodeList Object, Node.js Integration, Nullish Coalescing Operator, Number Object, Object.create Method, Object.assign Method, Object.defineProperty, Object.entries Method, Object.freeze Method, Object.is Method, Object.keys Method, Object.seal Method, Object.values Method, Observer Pattern in JavaScript, OffscreenCanvas API, Onclick Event, Online and Offline Events, Optional Chaining Operator, Origin Property, Output Encoding, Overflow Property in CSS, Page Visibility API, PageX and PageY Properties, ParentNode Interface, parseFloat Function, parseInt Function, Partial Application, Passive Event Listeners, Path2D Objects, Performance API, Persistent Storage, Pointer Events, Pop Method in Arrays, PopStateEvent, PostMessage Method, Promise.all Method, Promise.any Method, Promise.race Method, Promises in JavaScript, Prompt Dialogs, Prototype Chain, Prototypal Inheritance, Proxy Objects in JavaScript, Push Method in Arrays, Query Selector Methods, QueueMicrotask Function, Radio Buttons in Forms, Random Numbers in JavaScript, Range Input, Readonly Properties, Reference Errors, Reflect API, Regular Expressions, Relative URLs, Rem Units in CSS, Remote Script Execution, Request Animation Frame, Resize Events, Resize Observer API, Rest Parameters, Return Statement, Revealing Module Pattern, Reverse Method in Arrays, Rich Text Editing, Robot Framework Integration, Same-Origin Policy, Screen Orientation API, Script Tag in HTML, Scroll Events, scrollIntoView Method, scrollTo Method, Selection API, Self-Invoking Functions, Semicolons in JavaScript, Server-Sent Events, Service Workers, Set Object in JavaScript, Set Timeout and Set Interval, Shadow DOM, SharedArrayBuffer, Short-Circuit Evaluation, slice Method in Arrays, sort Method in Arrays, Source Maps, Spatial Navigation, splice Method in Arrays, Spread Operator, SQL Injection Prevention, Stack Traces, State Management in Web Apps, Static Methods, Storage Event, String Methods in JavaScript, Strict Mode, Structural Typing, Style Manipulation, Subresource Integrity, switch Statement, Symbol Data Type, Synthetic Events, Tabindex Attribute, Template Literals, Temporal Dead Zone, Text Content Property, Text Direction in CSS, Text Nodes, Throttle Function, throw Statement, Timers in JavaScript, toFixed Method, toString Method, Touch Events, Touch Interface, Traceur Compiler, Transpilers, Tree Shaking, Try...Catch Statement, Type Coercion, Typed Arrays, TypeError Exceptions, typeof Operator, Underscore.js Integration, Unicode in JavaScript, Unicode Normalization, Unary Operators, Undefined Value, Unhandled Rejection, Unit Testing in JavaScript, unshift Method in Arrays, URL API, URLSearchParams, Use Strict Directive, User Timing API, Validation in Forms, ValueOf Method, Variable Hoisting, Variables in JavaScript, Vibration API, Viewport Meta Tag, Visibility Property in CSS, Void Operator, Wake Lock API, WeakMap Object, WeakRef Object, WeakSet Object, Web Animations API, Web Audio API, Web Bluetooth API, Web Components, Web Cryptography API, Web GL, Web Notifications API, Web Real-Time Communications (WebRTC), Web Sockets, Web Speech API, Web Storage API, Web Workers, WebAssembly Integration, Wheel Event, While Loop, Window Object, Window.location Property, Window.postMessage Method, Worker Threads, XML Parsing in JavaScript, XMLHttpRequest Object, XPath Evaluation, XR (Extended Reality) APIs, Yield Keyword, Z-Index Property in CSS

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