The 11 Best Chrome Extensions for Web Developers
Eleven Chrome extensions web developers still rely on for debugging, design checks, accessibility and SEO audits, plus what DevTools now does itself.
Key points
- Every extension here was live in the Chrome Web Store and recently updated when we checked in October 2026.
- Chrome removed all remaining Manifest V2 extensions from the store on August 31, 2026, so several older favorites are gone.
- Some jobs no longer need an extension at all: device emulation, Core Web Vitals and saving edits to source files are built into DevTools.
- Extensions can read the pages you visit. Install only what you use, from developers you trust, and remove the rest.
What has changed since our first list
We first published this list in 2015, and Chrome’s extension platform has changed a lot since then. Google phased out the older Manifest V2 extension format and, on August 31, 2026, removed all remaining Manifest V2 extensions from the Chrome Web Store. Several tools from our original list, including Check My Links, Linkclump and the PageSpeed Insights checker, are no longer available there.
For this update we kept the extensions that are still maintained, replaced the ones that disappeared and grouped them by the job they do.
Inspect and debug
1. Web Developer
Chris Pederick’s Web Developer extension adds a toolbar button packed with quick switches: disable CSS or JavaScript, outline elements, display image details and alt text, view form details and much more. It started life as a Firefox add-on and is still one of the fastest ways to see how a page is put together.
2. React Developer Tools
Meta’s React Developer Tools adds Components and Profiler tabs to DevTools. You can inspect the component tree, check and edit props and state, and record renders to find what is slowing an interface down. If you build with Vue, the official Vue.js devtools extension does the same job for Vue apps.
3. JSON Formatter
JSON Formatter turns raw JSON into a readable, collapsible tree with syntax highlighting and clickable URLs, and switches back to the raw text with one click. It is invaluable when you work with APIs, including the WordPress REST API.
Design and front-end checks
4. WhatFont
Hover over any text with WhatFont to see which font it uses. Click for the details, including where the font comes from, its line height and letter spacing, and copy any value or all of the CSS at once.
5. ColorZilla
ColorZilla adds an eyedropper that reads the color of any pixel, an advanced color picker, a CSS gradient generator and a page color analyzer that pulls the palette from any site. It is a quick way to check that a build matches the brand colors in the design.
6. Window Resizer
Window Resizer resizes the browser window or just the viewport to preset dimensions with one click or a keyboard shortcut. The preset list is fully customizable, so you can match your project’s breakpoints. When you also need touch input or a mobile user agent, use DevTools’ device mode instead.
Audit performance, accessibility and SEO
7. Lighthouse
Google’s open-source Lighthouse audits a page for performance, accessibility, best practices and SEO, then explains how to fix what fails. It is also built into DevTools as its own panel. The extension is handy when you want to start an audit from the toolbar.
8. axe DevTools
Deque’s axe DevTools runs automated accessibility tests on axe-core, the widely used open-source testing engine, and explains each issue with guidance on fixing it. The free version tests one page at a time, which suits checks during development.
9. WAVE
WebAIM’s WAVE extension marks accessibility issues directly on the page, so you can see exactly where a missing label or low-contrast text sits. Its errors align with WCAG 2.2 failures, and because everything runs in your browser it works on local, staging and password-protected pages. Automated tools only catch part of the picture, so pair WAVE and axe with a keyboard and screen reader check.
10. Detailed SEO Extension
The Detailed SEO Extension shows a page’s title tag, meta description, meta robots tag and other key on-page details in one click. It saves digging through source code when you are checking a launch or reviewing a competitor’s page.
Research
11. Wappalyzer
Wappalyzer shows what a website is built with: its CMS, frameworks, ecommerce platform, JavaScript libraries, analytics tools and more. It is useful for scoping a project, planning a migration or understanding a competitor’s setup, and results can be exported to CSV.
Old favorites now built into Chrome
Several jobs that once needed an extension are now handled by DevTools itself:
- Device mode simulates phone and tablet screens, touch input and mobile user agents. See Chrome’s guide to device mode.
- Core Web Vitals appear live in the Performance panel. Google ended support for the Web Vitals extension on January 7, 2025 and moved its features there.
- Workspaces let you save changes made in DevTools to your source files, the job DevTools Autosave used to do.
- Lighthouse runs from its own DevTools panel, with nothing to install.
Keep your extensions in check
Extensions can read and change the pages you visit, including admin screens and staging sites. Install only the ones you use, check the permissions each one asks for, prefer developers with a clear website and support page, and remove anything you have stopped using. A lean browser profile is faster too.
Need a second pair of eyes on a build? Our technical SEO and web design teams can review performance, accessibility and on-page SEO before you launch. Get in touch.
