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Browser Extensions · head to head

Greasemonkey vs WhatFont

Greasemonkey logo

Greasemonkey

Browser Extensions

The original userscript manager, for Firefox

From
Free
Rated
-
Full reviewWebsite
WhatFont logo

WhatFont

Browser Extensions

Identify fonts on web pages

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Greasemonkey firefox only. There is no Chrome, Edge or Safari build and there never has been.; WhatFont can only detect web-safe fonts and fonts loaded via web font services
  • They diverge on capability: Greasemonkey covers Userscript execution, WhatFont covers Font detection.
  • Prices and features above were last checked on 15 September 2026.

Where they differ

Only the attributes on which Greasemonkey and WhatFont actually diverge.

Attributes where Greasemonkey and WhatFont differ
AttributeGreasemonkeyWhatFont
Pricing modelopen-sourceUnknown
PlatformsFirefoxChrome, Firefox, Arc
FoundedUnknown2011

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 Greasemonkey

  • Userscript execution
  • Built-in script editor
  • GM. API
  • @resource support
  • Script localisation
  • Firefox for Android

Only in WhatFont

  • Font detection
  • Typography info
  • Service detection
  • Hover inspection
  • Chrome support
  • Firefox support
  • Edge support
  • Safari support

What people use each for

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

Greasemonkey

  • Restyling or de-cluttering a site you use dailynot WhatFont
  • Automating a repetitive action on a web applicationnot WhatFont
  • Adding a missing feature to a site you do not controlnot WhatFont
  • Running userscripts on Firefox for Androidnot WhatFont
  • Writing and testing your own scripts in the browsernot WhatFont

WhatFont

  • Identifying typefaces used on competitor websites for design researchnot Greasemonkey
  • Sourcing font inspiration from high-performing landing pagesnot Greasemonkey
  • Discovering web font services like Google Fonts or Typekit on sitesnot Greasemonkey

Where each one falls short

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

Greasemonkey

  • Firefox only. There is no Chrome, Edge or Safari build and there never has been.
  • Its API diverged from the Tampermonkey conventions most shared scripts are written against, so a script from a sharing site may need adjusting to run.
  • The dashboard is plainer than Tampermonkey's, with no diff view when a script updates itself.
  • No cloud sync of the kind Tampermonkey and Violentmonkey offer; moving machines means exporting.
  • A userscript manager can read and rewrite every page you visit, so the security of the arrangement depends entirely on the scripts you choose to install.

WhatFont

  • Can only detect web-safe fonts and fonts loaded via web font services
  • Does not work on images with embedded text or rasterized typography
  • Limited to inspecting single text elements at a time

Pricing, plan by plan

Greasemonkey

Free
  • Open sourceFree
    • Unlimited scripts
    • Built-in editor
    • No account required

WhatFont

Free
  • FreeFree
    • Font inspection on any website
    • Font family identification
    • Font size and weight detection

Which should you pick?

Choose Greasemonkey if

  • You need userscript execution.
  • You want to start without paying.
  • You work on Firefox.
  • You also want built-in script editor.
Greasemonkey review

Choose WhatFont if

  • You need font detection.
  • You want to start without paying.
  • You work on Chrome, Firefox, Arc.
  • You also want typography info.
WhatFont review

Questions people ask

Is Greasemonkey or WhatFont better?
Neither clearly leads. Greasemonkey starts at Free and WhatFont at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Greasemonkey or WhatFont?
Greasemonkey starts at Free and WhatFont at Free.
Does Greasemonkey or WhatFont run on more platforms?
Greasemonkey runs on Firefox. WhatFont runs on Chrome, Firefox, Arc.
Can I use Greasemonkey for free?
Both have a free tier, so you can try either at no cost before committing.
What is Greasemonkey best used for?
Greasemonkey is most often used for restyling or de-cluttering a site you use daily, automating a repetitive action on a web application, adding a missing feature to a site you do not control, running userscripts on firefox for android. Of those, restyling or de-cluttering a site you use daily and automating a repetitive action on a web application are not what WhatFont is typically brought in for.
What can Greasemonkey do that WhatFont cannot?
Greasemonkey covers Userscript execution, Built-in script editor, GM. API, @resource support. WhatFont covers Font detection, Typography info, Service detection, Hover inspection.

Answered from the vendors’ own pages

Greasemonkey: Is Greasemonkey still maintained?

Yes. Version 4.14 was released on 2 June 2026, and the project has an active repository, bug tracker and discussion groups.

Source
WhatFont: How do I use WhatFont to inspect fonts?

Click the WhatFont icon in your browser toolbar to activate it, then hover over any text on a webpage to see the font name and details in a pop-up. Click the text to reveal additional information like font style, weight, color, and font samples.

Source
Greasemonkey: Does Greasemonkey work on Chrome?

No. It is a Firefox extension and has never shipped for Chrome. Violentmonkey and Tampermonkey are the equivalents there.

Source
WhatFont: What browsers does WhatFont support?

WhatFont works on Google Chrome, Firefox, and Arc browser. It is available as a free extension in each browser's extension store.

Source
Greasemonkey: Will Tampermonkey scripts run in Greasemonkey?

Often, but not always. Greasemonkey's API diverged from the conventions most shared scripts are written against, so a script may need its header or its GM calls adjusted.

Source
WhatFont: Is WhatFont free?

Yes. WhatFont is a completely free browser extension with no paid tier or premium features. It is maintained as a free tool for designers and developers.

Source
Greasemonkey: Does Greasemonkey run on mobile?

On Firefox for Android, from version 4.12. There is no iOS build, because Firefox on iOS cannot load extensions of this kind.

Source
Greasemonkey: What is the GM API?

The set of functions a userscript manager exposes to scripts, named after Greasemonkey, which defined it. Greasemonkey supports the promise-based GM. form including GM.xmlHttpRequest and GM.registerMenuCommand.

Source
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