Top Chrome Extensions Every Web Developer Needs
The right Chrome extensions can shave hours off your weekly workflow by putting powerful inspection and debugging tools one click away. From identifying fonts and colors to profiling performance and detecting tech stacks, these extensions cover the gaps that Chrome DevTools alone does not fill. Here are the extensions that earn a permanent spot in every web developer's toolbar.
Font Finder — Identify Any Font on the Web
Font Finder lets you hover over any text element on a webpage and instantly see its complete CSS font properties: font-family, font-size, font-weight, font-style, line-height, color (in both HEX and RGB), and letter-spacing. Unlike built-in DevTools, which require you to inspect an element and hunt through computed styles, Font Finder surfaces typography information in a clean overlay with a single hover — no clicking, no panel switching. It is particularly valuable when reverse-engineering design systems or auditing client sites where you need to quickly catalog every typeface in use. The extension is completely free, lightweight (no background processes or analytics), and works across all Chromium-based browsers including Chrome, Edge, Brave, and Arc. For designers handing off specs to developers or developers trying to match a reference design, Font Finder eliminates the guesswork and gives you copy-ready CSS values in seconds.
React Developer Tools
React Developer Tools adds two panels to Chrome DevTools: Components and Profiler. The Components panel shows the full React component tree with live props, state, hooks, and context values for every component instance — you can edit state and props directly in the panel and see changes reflected immediately, which is invaluable for debugging conditional rendering and state-driven UI bugs. The Profiler panel records render commits and shows exactly which components re-rendered, why they re-rendered (props changed, state changed, parent re-rendered), and how long each render took in milliseconds. This makes it the primary tool for diagnosing unnecessary re-renders and optimizing React performance. The extension also highlights component updates visually on the page when the 'Highlight updates' option is enabled, making it easy to spot components that re-render on every keystroke or scroll event. It works with all React versions from 16 onward, including React Server Components in Next.js App Router.
Lighthouse / PageSpeed Insights Extension
The Lighthouse Chrome extension runs the same audits as Google's PageSpeed Insights directly in your browser, generating a comprehensive report covering Performance, Accessibility, Best Practices, SEO, and Progressive Web App categories. For performance, it measures Core Web Vitals (LCP, CLS, FID/INP), Total Blocking Time, Speed Index, and Time to Interactive, with specific recommendations like 'Eliminate render-blocking resources' or 'Serve images in next-gen formats' tied to estimated savings in milliseconds or kilobytes. The extension version is especially useful during local development because it audits your localhost without requiring a deployed URL, letting you catch performance regressions before they hit production. You can configure device emulation (mobile vs desktop), throttling presets, and which categories to audit, keeping scan times short when you only care about performance. Running Lighthouse on every PR or feature branch as part of your workflow catches font loading regressions, accessibility violations, and SEO issues that code review alone would miss.
ColorZilla — Color Picker & Gradient Generator
ColorZilla provides a page-level eyedropper that samples the exact color of any pixel on a webpage and copies it to your clipboard in HEX, RGB, HSL, or CSS custom property format. Beyond the eyedropper, it includes a CSS gradient generator with visual controls for direction, color stops, and gradient type (linear, radial, conic), outputting production-ready CSS with vendor prefixes where still needed. The color history feature maintains a palette of recently sampled colors, which is extremely useful when extracting a color system from a reference design — you can sample an entire page's palette in under a minute. ColorZilla also shows the color of the element under your cursor in real time in the toolbar, so you can quickly scan a page's color usage without committing to a sample. For developers who spend time matching designs in Figma or Sketch to browser output, ColorZilla closes the loop between 'what color is this supposed to be' and 'what color is the browser actually rendering'.
Wappalyzer — Technology Detector
Wappalyzer detects the technologies powering any website and displays them organized by category: JavaScript frameworks (React, Vue, Svelte), CMS (WordPress, Shopify), analytics (GA4, Plausible), hosting (Vercel, Netlify, AWS), font services (Google Fonts, Adobe Fonts, Typekit), and dozens more. A single click on the toolbar icon reveals the full tech stack, which is invaluable for competitive analysis, client audits, and understanding how high-performing sites are built. When evaluating a potential technology choice, checking how major sites in your industry use it provides real-world validation that documentation cannot. Wappalyzer identifies technologies through DOM patterns, HTTP headers, JavaScript global variables, and meta tags — its detection database covers over 6,000 technologies and is actively maintained. The free tier covers basic detection; the paid tiers add features like bulk site analysis and CRM integrations, but the free version provides everything a developer needs for day-to-day use.
JSON Viewer — Format & Inspect API Responses
JSON Viewer automatically formats raw JSON responses in the browser with syntax highlighting, collapsible nodes, and clickable URLs — transforming an unreadable wall of minified text into a navigable tree structure. When you hit an API endpoint directly in the browser tab, the extension activates automatically, applying a dark or light theme and showing the data hierarchy with indent guides and bracket matching. Most JSON viewers also let you search and filter within the response, copy individual node paths (like data.users[0].email), and toggle between tree and raw views. This is significantly faster than copying JSON into an external formatter or piping curl output through jq for quick API exploration. For developers who work with REST APIs, GraphQL responses, or JSON configuration files served over HTTP, JSON Viewer is one of those extensions that you install once and then wonder how you ever worked without it.
WhatRuns — Deeper Technology Identification
WhatRuns complements Wappalyzer by providing deeper detection of themes, plugins, and server-side technologies that surface-level scanners miss. It identifies WordPress themes and plugins by name, detects specific CDN configurations (Cloudflare vs Fastly vs CloudFront), and recognizes A/B testing tools, tag managers, and marketing automation platforms. Where Wappalyzer focuses on the frontend framework and CMS layer, WhatRuns digs into the middleware and infrastructure, giving you a more complete picture of a site's architecture. It also tracks technology changes over time — you can follow a site and get notified when they switch from one technology to another, which is useful for tracking industry trends or monitoring competitor stacks. For freelancers and agency developers who regularly audit prospective client sites or scope migration projects, the combination of Wappalyzer for broad detection and WhatRuns for deep plugin-level detail covers the full technology identification workflow.
Responsive Viewer — Multi-Device Preview
Responsive Viewer displays your page in multiple device viewports simultaneously in a single browser tab, showing how your layout renders across phones, tablets, and desktops at the same time. Unlike Chrome DevTools' device emulation which shows one viewport at a time, Responsive Viewer lets you see an iPhone SE, iPhone 14 Pro, iPad, and a 1440px desktop side by side, instantly revealing breakpoint issues and overflow problems. You can configure custom viewport sizes to match your project's specific breakpoints and device targets, and all viewports scroll in sync so you can inspect any section of the page across all sizes simultaneously. The screenshot feature captures all viewports at once, generating a single image that is perfect for design reviews, QA documentation, and client presentations. For developers who work with responsive designs daily, this extension replaces the tedious cycle of resizing the browser window or switching between device presets in DevTools, saving significant time during CSS debugging and cross-device testing.
Try Font Finder Now
The fastest way to identify fonts on any website. Install the free Chrome extension and start inspecting typography in one click.