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Best Chrome Extensions for Developers

Last updated · picks re-checked against the Chrome Web Store

Developer extensions should extend DevTools rather than duplicate it. The ones worth installing add a panel or a transform you would otherwise write yourself.

How we picked

  • • Extends rather than duplicates DevTools
  • • No measurable overhead when idle
  • • Actively maintained against browser updates
  • • Sane permission requests

At a glance

#ExtensionBest forRatingUsersPricing
1React Developer ToolsReact developers debugging component state and render performance.3.95M+
Free
2JSON FormatterAnyone poking at REST APIs directly in the browser.4.32M+
Free
3WappalyzerDevelopers, agencies and sales teams researching what a site is built with.4.63M+
Freemium
4ColorZillaDesigners and front-end developers matching colours from live sites.4.64M+
Free
5WhatFontDesigners auditing typography on competitor and reference sites.4.03M+
Free

Ratings and install counts come from each extension's Chrome Web Store listing. A dash means the figures have not been synced yet.

  1. React Developer Tools Chrome extension logo

    1. React Developer Tools

    Inspect React component trees, props and state.

    Best for: React developers debugging component state and render performance.

    3.9~5M+ users
    Free
    View ExtensionAlternativesStore
  2. JSON Formatter Chrome extension logo

    2. JSON Formatter

    Makes raw JSON responses readable in the browser.

    Best for: Anyone poking at REST APIs directly in the browser.

    4.3~2M+ users
    Free
    View ExtensionAlternativesStore
  3. Wappalyzer Chrome extension logo

    3. Wappalyzer

    Identifies the technology stack behind any website.

    Best for: Developers, agencies and sales teams researching what a site is built with.

    4.6~3M+ users
    Freemium
    View ExtensionAlternativesStore
  4. ColorZilla Chrome extension logo

    4. ColorZilla

    Eyedropper, colour picker and gradient generator.

    Best for: Designers and front-end developers matching colours from live sites.

    4.6~4M+ users
    Free
    View ExtensionAlternativesStore
  5. WhatFont Chrome extension logo

    5. WhatFont

    Identify the fonts used on any web page.

    Best for: Designers auditing typography on competitor and reference sites.

    4.0~3M+ users
    Free
    View ExtensionAlternativesStore

What to know before choosing

Framework devtools are the clearest win: inspecting a component tree with live props and state beats console logging, and the profiler turns "it feels slow" into a specific render count. Keep them enabled only in development profiles, since they add overhead to very large trees.

The other two categories are quality-of-life. A JSON pretty-printer makes browsing REST endpoints directly tolerable, with collapsible nodes and clickable links instead of a wall of text. Stack detection answers the "what is this built with" question in a second, which is useful for competitive research and for deciding whether a bug is yours or a vendor's.

Compare the shortlist head-to-head

Narrowed it to two? These side-by-side comparisons settle it with a feature table and a verdict.

Wappalyzer vs JSON FormatterStack detection for recon work against readable API responses in the browser.ColorZilla vs WhatFontBoth are design extensions people shortlist together for design — see how ratings, install base, pricing and day-to-day use differ.React Developer Tools vs WappalyzerBoth are developer tools extensions people shortlist together — see how ratings, install base, pricing and day-to-day use differ.React Developer Tools vs JSON FormatterBoth are developer tools extensions people shortlist together — see how ratings, install base, pricing and day-to-day use differ.All comparisonsThe full compare hub, grouped by category.

Alternatives to the top picks

React Developer Tools alternativesClosest replacements for React Developer Tools, ranked by fit.JSON Formatter alternativesClosest replacements for JSON Formatter, ranked by fit.Wappalyzer alternativesClosest replacements for Wappalyzer, ranked by fit.ColorZilla alternativesClosest replacements for ColorZilla, ranked by fit.WhatFont alternativesClosest replacements for WhatFont, ranked by fit.

Frequently asked questions

Do developer extensions slow down Chrome?

Framework devtools add overhead on large component trees. Keep them in a separate development profile.

How can I read raw JSON API responses more easily?

A JSON formatter pretty-prints and collapses responses in the browser, no client needed.

How do I find out what a website is built with?

A technology detection extension reports the frameworks, CMS, analytics and hosting behind the current page.