Softwr

Browser Extensions · head to head

Greasemonkey vs Stay

Greasemonkey logo

Greasemonkey

Browser Extensions

The original userscript manager, for Firefox

From
Free
Rated
-
Full reviewWebsite
Stay logo

Stay

Browser Extensions

Safari userscript manager that runs Tampermonkey scripts

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.; Stay apple only. No Chrome, Firefox or Edge build, so it cannot serve a cross-browser workflow.
  • They diverge on capability: Greasemonkey covers Userscript execution, Stay covers Tampermonkey and Violentmonkey compatibility.
  • Prices and features above were last checked on 15 September 2026.

Where they differ

Only the attributes on which Greasemonkey and Stay actually diverge.

Attributes where Greasemonkey and Stay differ
AttributeGreasemonkeyStay
Pricing modelopen-sourceone-time
PlatformsFirefoxSafari, iOS, macOS

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 Stay

  • Tampermonkey and Violentmonkey compatibility
  • Userscript management
  • Cross-device bookmark sync
  • Download manager
  • Dark mode
  • One-time purchase across platforms

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

Stay

  • Running Tampermonkey scripts on Safarinot Greasemonkey
  • Running userscripts on iPhone and iPadnot Greasemonkey
  • Syncing bookmarks across Apple and non-Apple devicesnot Greasemonkey
  • Managing downloads into categorised folders on iOSnot Greasemonkey
  • Forcing dark mode on sites that do not offer itnot 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.

Stay

  • Apple only. No Chrome, Firefox or Edge build, so it cannot serve a cross-browser workflow.
  • The free tier is deliberately limited, so the practical product is the paid one.
  • Compatibility with Tampermonkey and Violentmonkey scripts is a translation layer rather than the real thing, and a script relying on an unusual GM function may not behave identically.
  • It bundles bookmark sync, downloads and dark mode alongside the script manager, which is more surface area than some people want from an extension with access to every page.
  • A much smaller project than the established managers, so fewer scripts are tested against it.

Pricing, plan by plan

Greasemonkey

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

Stay

Free
  • FreeFree
    • Limited functionality
  • Lifetime$5/one-time
    • All features
    • iPhone, iPad and Mac
    • Lifetime updates

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 Stay if

  • You need tampermonkey and violentmonkey compatibility.
  • You want to start without paying.
  • You work on Safari, iOS, macOS.
  • You also want userscript management.
Stay review

Questions people ask

Is Greasemonkey or Stay better?
Neither clearly leads. Greasemonkey starts at Free and Stay at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Greasemonkey or Stay?
Greasemonkey starts at Free and Stay at Free.
Does Greasemonkey or Stay run on more platforms?
Greasemonkey runs on Firefox. Stay runs on Safari, iOS, macOS.
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 Stay is typically brought in for.
What can Greasemonkey do that Stay cannot?
Greasemonkey covers Userscript execution, Built-in script editor, GM. API, @resource support. Stay covers Tampermonkey and Violentmonkey compatibility, Userscript management, Cross-device bookmark sync, Download manager.

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
Stay: Can Stay run Tampermonkey scripts?

Yes. It supports its own native scripts and also scripts written for Tampermonkey and Violentmonkey, which is the main reason to choose it on Safari.

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
Stay: How much does Stay cost?

A one-time payment, reported at around $5, covering iPhone, iPad and Mac with lifetime updates and no subscription. A free version with limited functionality is available.

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
Stay: Does Stay work on iPhone?

Yes. It supports Safari across iPhone, iPad and Mac, and the single purchase covers all three.

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
Stay: What can userscripts do in Safari through Stay?

The vendor's examples are automatic pagination, immersive translation, redirect blocking and aggregated search. Anything a userscript can do on another browser is broadly in scope, subject to Safari's own restrictions.

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
Stay: Is Stay open source?

The project publishes source on GitHub, and the app is distributed through the App Store as a paid product with a limited free tier.

Source
Share

Related pages

More on Greasemonkey

More on Stay

Keep looking

Other head to heads