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Browser Extensions · head to head

Greasemonkey vs Storybook

Greasemonkey logo

Greasemonkey

Browser Extensions

The original userscript manager, for Firefox

From
Free
Rated
-
Full reviewWebsite
Storybook logo

Storybook

Technology

Build component driven UIs faster

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.; Storybook requires JavaScript framework knowledge for full utilization
  • They diverge on capability: Greasemonkey covers Userscript execution, Storybook covers Component isolation.
  • Prices and features above were last checked on 17 September 2026.

Where they differ

Only the attributes on which Greasemonkey and Storybook actually diverge.

Attributes where Greasemonkey and Storybook differ
AttributeGreasemonkeyStorybook
Pricing modelopen-sourceUnknown
PlatformsFirefoxWeb, React Native, iOS, Android, Flutter
CategoryBrowser ExtensionsTechnology
FoundedUnknown2017

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

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 Storybook

  • Component isolation
  • Interactive development
  • Visual testing
  • Documentation generation
  • Accessibility testing
  • Interaction testing
  • Addons ecosystem
  • Hot module reloading

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 Storybook
  • Automating a repetitive action on a web applicationnot Storybook
  • Adding a missing feature to a site you do not controlnot Storybook
  • Running userscripts on Firefox for Androidnot Storybook
  • Writing and testing your own scripts in the browsernot Storybook

Storybook

  • Component developmentnot Greasemonkey
  • Design system documentationnot Greasemonkey
  • Visual regression testingnot Greasemonkey
  • UI component showcasenot Greasemonkey
  • Team collaborationnot 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.

Storybook

  • Requires JavaScript framework knowledge for full utilization
  • Limited native support for non-web platforms compared to specialized tools

Pricing, plan by plan

Greasemonkey

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

Storybook

Free

No published plan breakdown. See the Storybook review.

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 Storybook if

  • You need component isolation.
  • You want to start without paying.
  • You work on Web, React Native, iOS, Android, Flutter.
  • You also want interactive development.
Storybook review

Questions people ask

Is Greasemonkey or Storybook better?
Neither clearly leads. Greasemonkey starts at Free and Storybook at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Greasemonkey or Storybook?
Greasemonkey starts at Free and Storybook at Free.
Does Greasemonkey or Storybook run on more platforms?
Greasemonkey runs on Firefox. Storybook runs on Web, React Native, iOS, Android, Flutter.
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 Storybook is typically brought in for.
What can Greasemonkey do that Storybook cannot?
Greasemonkey covers Userscript execution, Built-in script editor, GM. API, @resource support. Storybook covers Component isolation, Interactive development, Visual testing, Documentation generation.

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
Storybook: Is Storybook free and open source?

Yes, Storybook is completely free and open source with source code hosted on GitHub. It has 2,282 contributors and approximately 83.58 million monthly installations.

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
Storybook: What frameworks does Storybook support?

Storybook integrates with React, Vue, Angular, Svelte, and has been extended to support React Native, Android, iOS, and Flutter for mobile development.

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
Storybook: What are the main capabilities of Storybook?

Storybook enables component development in isolation, interaction testing, visual testing, documentation, and sharing components with designers and stakeholders.

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
Storybook: How is Storybook maintained?

Storybook is maintained by a community of 2,282 contributors. It originated from a startup called Kadira, was handed to the community in 2017, and has been community-driven since Storybook 3.0.

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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