EVERYTHING XIAOMI
Get listed
JSON OS logo

JSON OS

JSON OS is a free web workbench that brings together a JSON editor and Markdown Studio.

Place
#13 of 29
Score
6.2
JSON OS's website

What JSON OS is

JSON OS is a free web workbench that brings together a JSON editor and Markdown Studio. The JSON editor can show and edit data in tree, text, or table form, and lets users format, minify, sort, validate against JSON Schema, and repair malformed input. It can compare two documents side by side, apply MongoDB-style filters, and export JSON arrays to CSV. The workspace supports up to three panes. Markdown Studio handles GitHub-Flavored Markdown, diagrams, math, highlighted code, and URL embeds from services including YouTube, Vimeo, GitHub Gist, and Twitter/X. It can export Markdown source, copy rendered HTML, or download a standalone HTML file. Users can open or drop JSON and Markdown files. The maker says the app needs no signup and processes data locally, with nothing leaving the device. It also says rendered Markdown is sanitized, stripping scripts and untrusted iframes. JSON OS is available in a browser and has a free plan.

Good

  • Tree, text, and table JSON views
  • Schema validation and malformed JSON repair
  • Side-by-side comparison and MongoDB-style filters
  • Markdown supports diagrams, math, and embeds
  • Exports JSON arrays to CSV

Watch out

  • JSON workspace is limited to three panes
  • Available on web only

Who it suits

JSON OS suits people who need browser-based tools for editing, checking, comparing, or exporting JSON, as well as writing and previewing Markdown. It may also fit users who want a no-signup workflow and local processing, as described by the maker.

Verdict

JSON OS combines several JSON editing and Markdown tasks in one browser workbench. Its three-pane workspace limit and web-only availability are worth considering.

Plans and prices

From JSON OS's own pricing page, checked 8 Oct 2026.

All about pricing
PlanPriceWhat it gives you
FreeFreeBrowser-based JSON editor and Markdown previewer

The facts

Each one read from JSON OS's own pages, with the date it was checked.

What it does

Compare and query
The editor compares two documents side by side and supports MongoDB-style filters for querying JSON.checked 8 Oct 2026
CSV export
JSON arrays can be exported to CSV with a UTF-8 BOM for Excel compatibility.checked 8 Oct 2026
Embed integrations
Markdown URL embeds include YouTube, Vimeo, CodePen, CodeSandbox, JSFiddle, GitHub Gist, and Twitter/X.checked 8 Oct 2026
Embeds
Markdown URL embeds include YouTube, Vimeo, CodePen, CodeSandbox, JSFiddle, GitHub Gist, and Twitter/X.checked 8 Oct 2026
Exports
JSON arrays can be exported to CSV, and Markdown can be exported as source, copied as rendered HTML, or downloaded as standalone HTML.checked 8 Oct 2026
File use
Users can open or drop JSON and Markdown files, and the Markdown Studio can import .md files by drag and drop.checked 8 Oct 2026
Formatting
The editor can format, beautify, minify, and sort JSON keys.checked 8 Oct 2026
JSON editing
The JSON editor supports tree, text, and table views, plus formatting, minifying, and sorting keys.checked 8 Oct 2026
JSON views
The JSON editor can display and edit data in tree, text, or table view, with columns switchable independently.checked 8 Oct 2026
Local processing
The maker says processing runs locally in a Web Worker, data is persisted in IndexedDB, and nothing leaves the device.checked 8 Oct 2026
Markdown exports
Markdown Studio can export Markdown source, copy rendered HTML, or download a standalone HTML file.checked 8 Oct 2026
Markdown features
Markdown Studio supports GitHub-Flavored Markdown, Mermaid diagrams, KaTeX math, syntax-highlighted code, and embeds.checked 8 Oct 2026
Markdown safety
The maker says rendered HTML is sanitized with DOMPurify and scripts and untrusted iframes are stripped.checked 8 Oct 2026
Output sanitization
Rendered Markdown HTML is processed through DOMPurify, and scripts and untrusted iframes are stripped.checked 8 Oct 2026
Privacy and signup
The site says the app requires no signup, uploads, or server processing.checked 8 Oct 2026
Product
JSON OS is a free, browser-based workbench with a JSON editor and Markdown previewer; the maker says it requires no signup.checked 8 Oct 2026
Query and compare
It supports MongoDB-style JSON filters and side-by-side document comparison with sync-scroll and ignore rules.checked 8 Oct 2026
Repair
The editor repairs malformed JSON including smart quotes, trailing commas, unquoted keys, comments, and unclosed brackets.checked 8 Oct 2026
Schema validation
The editor validates JSON against JSON Schema using Ajv with format checks.checked 8 Oct 2026
Validation and repair
It validates JSON against JSON Schema and can repair issues including trailing commas, unquoted keys, and unclosed brackets.checked 8 Oct 2026
Workspace limit
The JSON workspace supports up to three panes.checked 8 Oct 2026

Alternatives to JSON OS

All alternatives
  1. 1JSONZen logo

    JSONZen

    Free planWebAPILinuxmacOS
    7.6$1 one-time
    Visit
  2. 2

    jaq

    Free planOpen sourceWebAPILinuxmacOS
    7.5Free plan
    Visit
  3. 3

    jq

    Free planWebLinuxmacOSSelf-hosted
    7.2Free plan
    Visit
  4. 4

    Dadroit JSON Viewer

    Free planWebLinuxmacOSWindows
    6.9From $98 a year
    Visit
  5. 5BracketView logo

    BracketView

    Free planWebLinuxWindows
    6.7From $27 a year
    Visit
  6. 6

    jidoujisho

    Free planAndroid
    6.6Free plan
    Visit