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Browser Extensions · head to head

FireMonkey vs React Developer Tools

FireMonkey logo

FireMonkey

Browser Extensions

User scripts and user styles in one Firefox extension

From
Free
Rated
-
React Developer Tools logo

React Developer Tools

Browser Extensions

Debug React applications in your browser

From
Free
Rated
-

The short version

  • Each has a real cost: FireMonkey firefox only, and requires a recent one: version 93 on desktop, 113 on Android.; React Developer Tools react Developer Tools is only available as a Chrome browser extension. No support for other browsers mentioned.
  • They diverge on capability: FireMonkey covers Scripts and styles together, React Developer Tools covers Component inspection.
  • Prices and features above were last checked on 15 September 2026.

Where they differ

Only the attributes on which FireMonkey and React Developer Tools actually diverge.

Attributes where FireMonkey and React Developer Tools differ
AttributeFireMonkeyReact Developer Tools
Pricing modelopen-sourcefree
PlatformsFirefoxChrome, Firefox, Edge
FoundedUnknown2004

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Browser Extensions).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in FireMonkey

  • Scripts and styles together
  • Monaco editor with ESLint
  • Unlimited client-side storage
  • Global injection
  • Notifications and clipboard
  • Firefox for Android

Only in React Developer Tools

  • Component inspection
  • Props/State viewing
  • Performance profiler
  • Hooks debugging
  • Chrome support
  • Firefox support
  • Edge support

What people use each for

The jobs each tool is most often brought in to do.

FireMonkey

  • Running user scripts and user styles without two separate extensionsnot React Developer Tools
  • Restyling sites with CSS alongside scripted behaviour changesnot React Developer Tools
  • Editing scripts in a full editor inside the browsernot React Developer Tools
  • Injecting CSS globally across every sitenot React Developer Tools
  • Managing a mixed library of scripts and styles from one dashboardnot React Developer Tools

React Developer Tools

  • Debugging React components during developmentnot FireMonkey
  • Inspecting component state and propsnot FireMonkey
  • Performance profiling of React applicationsnot FireMonkey

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

FireMonkey

  • Firefox only, and requires a recent one: version 93 on desktop, 113 on Android.
  • Not a drop-in replacement for Greasemonkey, Tampermonkey or Stylus. The project says so itself, so an existing library may need adjusting.
  • A much smaller user base than Tampermonkey or Violentmonkey, which means fewer people have hit the bug you are about to hit.
  • No Chrome, Edge or Safari build, so it cannot be the answer for anyone working across browsers.
  • Combining scripts and styles in one extension also combines the blast radius: one extension with permission to inject both into every page.

React Developer Tools

  • React Developer Tools is only available as a Chrome browser extension. No support for other browsers mentioned.

Pricing, plan by plan

FireMonkey

Free
  • Open sourceFree
    • MPL-2.0 licensed
    • Unlimited scripts and styles
    • No account required

React Developer Tools

Free
  • FreeFree
    • Component tree
    • Props inspection
    • State tracking

Which should you pick?

Choose FireMonkey if

  • You need scripts and styles together.
  • You want to start without paying.
  • You work on Firefox.
  • You also want monaco editor with eslint.

Choose React Developer Tools if

  • You need component inspection.
  • You want to start without paying.
  • You work on Chrome, Firefox, Edge.
  • You also want props/state viewing.

Questions people ask

Is FireMonkey or React Developer Tools better?
Neither clearly leads. FireMonkey starts at Free and React Developer Tools at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, FireMonkey or React Developer Tools?
FireMonkey starts at Free and React Developer Tools at Free.
Does FireMonkey or React Developer Tools run on more platforms?
FireMonkey runs on Firefox. React Developer Tools runs on Chrome, Firefox, Edge.
Can I use FireMonkey for free?
Both have a free tier, so you can try either at no cost before committing.
What is FireMonkey best used for?
FireMonkey is most often used for running user scripts and user styles without two separate extensions, restyling sites with css alongside scripted behaviour changes, editing scripts in a full editor inside the browser, injecting css globally across every site. Of those, running user scripts and user styles without two separate extensions and restyling sites with css alongside scripted behaviour changes are not what React Developer Tools is typically brought in for.
What can FireMonkey do that React Developer Tools cannot?
FireMonkey covers Scripts and styles together, Monaco editor with ESLint, Unlimited client-side storage, Global injection. React Developer Tools covers Component inspection, Props/State viewing, Performance profiler, Hooks debugging.

Answered from the vendors’ own pages

FireMonkey: What makes FireMonkey different from Violentmonkey?

It manages user styles as well as user scripts. The usual arrangement is a script manager plus a separate style manager such as Stylus; FireMonkey replaces both with one extension.

Source
React Developer Tools: How much does React Developer Tools cost?

React Developer Tools is completely free. It is a free browser extension with no subscription fees or costs.

Source
FireMonkey: Which browsers does FireMonkey support?

Firefox only. Desktop requires Firefox 93 or later and Android requires 113, with an API minimum of 102.

Source
React Developer Tools: Is React Developer Tools available for download?

Yes. React Developer Tools is available as a free extension on the Chrome Web Store for download at no cost.

Source
FireMonkey: Is FireMonkey open source?

Yes, under the MPL-2.0 licence.

Source
FireMonkey: Will my existing Tampermonkey scripts work?

Not necessarily. The project states that while it shares functionality with Greasemonkey, Tampermonkey and Stylus, there are differences, so scripts and styles written for those may need adjusting.

Source
FireMonkey: What editor does FireMonkey use?

Current versions use the Monaco editor with ESLint, the same editor component that powers VS Code.

Source
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