Is JSON Hero Open Source and Can I Self-Host It?

Updated

Yes. JSON Hero is 100% open source, and you have two ways to use it: the hosted version at jsonhero.io, or by forking the project on GitHub and running it yourself. The choice matters mainly for privacy and control — if your JSON contains sensitive data, self-hosting keeps it on infrastructure you manage, while the hosted version is the fastest way to get started.

What "open source" means here

The site states plainly that JSON Hero is "100% open source" and points to GitHub as the place to fork and run it. That gives you two practical options:

  • Use the hosted service at jsonhero.io — no setup, works in the browser.
  • Fork and self-host — you run the code yourself, which is the relevant option when you don't want your JSON leaving your own environment.

The page does not spell out the specific license terms, so if licensing matters for your use case, check the GitHub repository directly before relying on it.

Privacy: hosted vs. self-hosted

The site lists "Privacy" as a feature area, but the page evidence doesn't detail exactly how uploaded files are handled on the hosted version. That gap is itself the deciding factor:

Consideration Hosted (jsonhero.io) Self-hosted (fork on GitHub)
Setup effort None — open the site and drop a file You run and maintain it yourself
Where your JSON lives On the hosted service On your own infrastructure
Best for Quick, non-sensitive inspection Sensitive or regulated data
Sharing Built-in document links Depends on your own deployment

If your JSON is non-sensitive and you just want to inspect it, the hosted version is the low-friction choice. If it contains credentials, personal data, or anything you can't upload to a third party, self-hosting is the option the open-source model makes available to you.

What you get either way

Self-hosting doesn't cost you features — the same viewer runs in both cases. Per the site, that includes:

  • String detection — it figures out whether a string is an image, date, color, URL, or video, and shows a preview with copyable properties (href, origin, protocol, hostname, pathname, mimeType).
  • Edge-case discovery — view a field's related values to spot nulls, unexpected values, or missing fields, plus an inferred JSON schema.
  • Fast search — fuzzy matching across the whole file with keyboard shortcuts.
  • Sharing — link directly to the part of the document you're viewing.
  • Code view — switch to a raw code view.
  • Auto JSON Schema — generates JSON Schema (draft 2020-12) from your JSON.
  • VS Code plugin — view JSON files or selections in JSON Hero from inside VS Code.
  • Dark mode and keyboard shortcuts.

How to self-host

The page confirms you can "fork it on GitHub and run it yourself" but doesn't include install commands or environment requirements. To actually do it:

  1. Go to the GitHub repository linked from jsonhero.io.
  2. Fork or clone it.
  3. Follow the repository's own setup instructions — that's where the real prerequisites (runtime, dependencies, configuration) live, and they aren't reproduced on the marketing page.

If you only need to view a file once and it isn't sensitive, skip all of this and use the hosted version.