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Browser Extensions · head to head

SimilarWeb vs Tampermonkey

S

SimilarWeb

Browser Extensions

Website traffic and competitive analysis

From
Free
Rated
-
Full reviewWebsite
Tampermonkey logo

Tampermonkey

Browser Extensions

The most popular userscript manager

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: SimilarWeb browser extension data accuracy is lower than full platform; Tampermonkey only source code up to version 2.9 is GPLv3; all newer versions are distributed under a proprietary license despite the extension itself being free to use
  • They diverge on capability: SimilarWeb covers Traffic analytics, Tampermonkey covers Userscript management.

Where they differ

Only the attributes on which SimilarWeb and Tampermonkey actually diverge.

Attributes where SimilarWeb and Tampermonkey differ
AttributeSimilarWebTampermonkey
Pricing modelfreemiumUnknown
PlatformsWeb, Browser ExtensionWeb, Windows, macOS, Linux, Android
Founded20072010

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 SimilarWeb

  • Traffic analytics
  • Audience insights
  • Competitor research
  • Industry analysis

Only in Tampermonkey

  • Userscript management
  • Script editor
  • Auto-update
  • Cloud sync
  • Safari support
  • Opera support

Both cover

  • Chrome support
  • Firefox support
  • Edge support

What people use each for

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

SimilarWeb

No use cases recorded yet. See the SimilarWeb review.

Tampermonkey

  • Auto-run custom JavaScript to add features to specific websitesnot SimilarWeb
  • Block ads, remove clutter, or reformat page layout via community/personal userscriptsnot SimilarWeb
  • Run scripts sourced from Greasy Fork or similar userscript repositoriesnot SimilarWeb
  • Automate repetitive web tasks such as form-filling or redirect skipping via installed scriptsnot SimilarWeb

Where each one falls short

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

SimilarWeb

  • Browser extension data accuracy is lower than full platform
  • Full platform pricing is not transparent and requires quote-based inquiry

Tampermonkey

  • Only source code up to version 2.9 is GPLv3; all newer versions are distributed under a proprietary license despite the extension itself being free to use
  • Under Manifest V3, GM_webRequest is not (yet) supported
  • Under Manifest V3, GM_xmlhttpRequest fires only one progress event instead of streaming progress, requiring a responseType: 'stream' workaround
  • Since v5.3.2, Chrome/Edge (MV3) requires the user to manually enable Developer Mode, or from Chrome 138+ a per-extension 'Allow User Scripts' toggle, before any userscript will run

Pricing, plan by plan

SimilarWeb

Free
  • FreeFree
    • Traffic overview
    • Engagement metrics
    • Similar sites

Tampermonkey

Free

No published plan breakdown. See the Tampermonkey review.

Which should you pick?

Choose SimilarWeb if

  • You need traffic analytics.
  • You want to start without paying.
  • You work on Web, Browser Extension.
  • You also want audience insights.
SimilarWeb review

Choose Tampermonkey if

  • You need userscript management.
  • You want to start without paying.
  • You work on Web, Windows, macOS, Linux, Android.
  • You also want script editor.
Tampermonkey review

Questions people ask

Is SimilarWeb or Tampermonkey better?
Neither clearly leads. SimilarWeb starts at Free and Tampermonkey at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, SimilarWeb or Tampermonkey?
SimilarWeb starts at Free and Tampermonkey at Free.
Does SimilarWeb or Tampermonkey run on more platforms?
SimilarWeb runs on Web, Browser Extension. Tampermonkey runs on Web, Windows, macOS, Linux, Android.
Can I use SimilarWeb for free?
Both have a free tier, so you can try either at no cost before committing.
What can SimilarWeb do that Tampermonkey cannot?
SimilarWeb covers Traffic analytics, Audience insights, Competitor research, Industry analysis. Tampermonkey covers Userscript management, Script editor, Auto-update, Cloud sync. Both handle Chrome support, Firefox support, Edge support.

Answered from the vendors’ own pages

SimilarWeb: Is the SimilarWeb browser extension free?

Yes. The SimilarWeb browser extension is completely free to install and use with no paid tiers and no credit card required.

Source
SimilarWeb: How many websites does SimilarWeb cover?

SimilarWeb provides access to intelligence from 1B+ websites and 8M apps, tracks 5B search terms and 250M display ads across 190 countries and 210 industries.

Source
SimilarWeb: How accurate is SimilarWeb extension data?

Browser extension data accuracy is lower than the full platform, but it is adequate for ballpark figures of traffic estimates.

Source
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Related pages

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