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Browser Extensions · head to head

Greasemonkey vs Sakai

Greasemonkey logo

Greasemonkey

Browser Extensions

The original userscript manager, for Firefox

From
Free
Rated
-
Full reviewWebsite
Sakai logo

Sakai

LMS

Open source learning management system governed by the Apereo Foundation

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.; Sakai the zero licence fee is misleading: running Sakai needs Java operations, database administration and upgrade testing capacity, and universities that costed only the hardware have ended up paying a hosting partner anyway.
  • They diverge on capability: Greasemonkey covers Userscript execution, Sakai covers Course sites.
  • Prices and features above were last checked on 17 September 2026.

Where they differ

Only the attributes on which Greasemonkey and Sakai actually diverge.

Attributes where Greasemonkey and Sakai differ
AttributeGreasemonkeySakai
Pricing modelopen-sourceOpen source, no licence fee
PlatformsFirefoxWeb, Linux, iOS, Android
CategoryBrowser ExtensionsLMS

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 Sakai

  • Course sites
  • Tests and Quizzes
  • Gradebook
  • Lessons
  • Assignments
  • Forums and messaging
  • LTI support
  • Self-hosting

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

Sakai

  • A university whose data protection policy or national regulation requires student coursework to stay on institution-controlled infrastructure inside a specific jurisdiction.not Greasemonkey
  • An institution that has been repriced twice by a commercial LMS vendor after ownership changes and wants a platform with no owner to sell it.not Greasemonkey
  • A university with an existing Java and Tomcat operations team, where the marginal cost of running one more Java application is genuinely low.not Greasemonkey
  • A consortium of institutions sharing one deployment and one set of local integrations rather than each paying separate per-student licences.not 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.

Sakai

  • The zero licence fee is misleading: running Sakai needs Java operations, database administration and upgrade testing capacity, and universities that costed only the hardware have ended up paying a hosting partner anyway.
  • The third-party teaching tool ecosystem builds and tests for Canvas first, so Sakai adopters do their own LTI integration work and occasionally wait for a vendor to certify against a platform it does not prioritise.
  • Because governance is a foundation of member institutions rather than a company, a feature only gets built if some institution funds an engineer to build it, so roadmap commitments are weaker than a vendor contract provides.
  • The interface, while improved through the version 20 to 25 cycle, still reads as older than Canvas or Brightspace, and academic staff who have used a commercial LMS elsewhere notice it immediately.
  • Adoption is concentrated in specific regions and sectors, so the pool of people who have run Sakai in production is small, making it harder to hire an administrator than for Moodle or Canvas.

Pricing, plan by plan

Greasemonkey

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

Sakai

Free
  • SakaiFree
    • Educational Community Licence, no licence fee
    • Full source on GitHub
    • Community support through Apereo lists and Jira
  • Commercial hosting and support$undefined/year
    • Provided by Apereo affiliates such as Longsight
    • Hosting, upgrades, backups and support
    • Quoted per institution, commonly by student headcount

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 Sakai if

  • You need course sites.
  • You want to start without paying.
  • You work on Web, Linux, iOS, Android.
  • You also want tests and quizzes.
Sakai review

Questions people ask

Is Greasemonkey or Sakai better?
Neither clearly leads. Greasemonkey starts at Free and Sakai at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Greasemonkey or Sakai?
Greasemonkey starts at Free and Sakai at Free.
Does Greasemonkey or Sakai run on more platforms?
Greasemonkey runs on Firefox. Sakai runs on Web, Linux, iOS, Android.
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 Sakai is typically brought in for.
What can Greasemonkey do that Sakai cannot?
Greasemonkey covers Userscript execution, Built-in script editor, GM. API, @resource support. Sakai covers Course sites, Tests and Quizzes, Gradebook, Lessons.

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
Sakai: Is Sakai still actively developed?

Yes. Version 25.0 shipped in 2025, 25.1 followed in November 2025, and further maintenance releases in the 25 line are planned, with commits continuing through 2026.

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
Sakai: Who owns Sakai?

No company does. Governance sits with the Apereo Foundation, a membership organisation of institutions, and the code is under the Educational Community Licence.

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
Sakai: What does it actually cost to run?

The software is free. The cost is Java hosting and staff, or a commercial hosting agreement with an Apereo affiliate such as Longsight, typically quoted by student headcount.

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
Sakai: How does it compare to Moodle?

Moodle has a far larger plugin ecosystem and installed base; Sakai has a cleaner assessment and gradebook model and is more common in research-intensive universities. Moodle is easier to hire for.

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
Sakai: Can we migrate off it later?

Yes, but course content export fidelity through Common Cartridge is imperfect, so budget for manual rebuilding of assessments as you would leaving any LMS.

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