Developer tools

Validate, format, and preview JSON, JSONL, XML, and Markdown — entirely in your browser.

Everything runs in your browser. Your data never leaves your device.

{
  "status": "ok", "count": 42
}

Validate, format, minify, and explore JSON with exact error line and column numbers.

{"id":1,"ok":true}
{"id":2,"ok":false}
{"id":3,"ok":true}

Validate JSON Lines (NDJSON) with per-line errors, minify, browse records, and convert to or from a JSON array.

<user id="42">
  <name>Ada</name>
</user>

Check XML well-formedness, pretty-print, and browse the element tree — with located errors.

# Release notes
- [x] ship it
**bold** and `code`

Write Markdown with a live, sanitized preview and lint hints. GitHub-flavored, XSS-safe.

▶ user "fix the auth test"
  ⚙ Bash npm test → ok
◀ assistant 212 tests pass

Upload a Claude Code, Codex, or other agent transcript (.jsonl) and explore it as an interactive graph and timeline: turns, tool calls, subagents, and token usage.