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Browser Extensions · head to head

JSON Viewer vs Tampermonkey

JSON Viewer logo

JSON Viewer

Browser Extensions

View JSON documents in the browser

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: JSON Viewer the project is MIT licensed open source code hosted on GitHub with no vendor and no paid tier; 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: JSON Viewer covers JSON formatting, Tampermonkey covers Userscript management.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which JSON Viewer and Tampermonkey actually diverge.

Attributes where JSON Viewer and Tampermonkey differ
AttributeJSON ViewerTampermonkey
Pricing modelfreeopen-source
PlatformsChrome, Firefox, EdgeWeb, Windows, macOS, Linux, Android
Founded20152010

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 JSON Viewer

  • JSON formatting
  • Syntax highlighting
  • Tree view
  • Search functionality

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.

JSON Viewer

No use cases recorded yet. See the JSON Viewer review.

Tampermonkey

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

Where each one falls short

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

JSON Viewer

  • The project is MIT licensed open source code hosted on GitHub with no vendor and no paid tier

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

JSON Viewer

Free
  • FreeFree
    • Syntax highlighting
    • Collapsible tree
    • Search

Tampermonkey

Free

No published plan breakdown. See the Tampermonkey review.

Which should you pick?

Choose JSON Viewer if

  • You need json formatting.
  • You want to start without paying.
  • You work on Chrome, Firefox, Edge.
  • You also want syntax highlighting.
JSON Viewer 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 JSON Viewer or Tampermonkey better?
Neither clearly leads. JSON Viewer 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, JSON Viewer or Tampermonkey?
JSON Viewer starts at Free and Tampermonkey at Free.
Does JSON Viewer or Tampermonkey run on more platforms?
JSON Viewer runs on Chrome, Firefox, Edge. Tampermonkey runs on Web, Windows, macOS, Linux, Android.
Can I use JSON Viewer for free?
Both have a free tier, so you can try either at no cost before committing.
What can JSON Viewer do that Tampermonkey cannot?
JSON Viewer covers JSON formatting, Syntax highlighting, Tree view, Search functionality. Tampermonkey covers Userscript management, Script editor, Auto-update, Cloud sync. Both handle Chrome support, Firefox support, Edge support.

Answered from the vendors’ own pages

Tampermonkey: How much does Tampermonkey cost?

Tampermonkey is completely free for all versions and across all supported browsers including Chrome, Edge, Safari, Opera, and Firefox.

Source
Tampermonkey: Is Tampermonkey available on all browsers?

Yes, Tampermonkey is available on Chrome 120 and later, Microsoft Edge, Safari, Opera Next, and Firefox with no cost.

Source
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