JSON/XML Formatter

A focused browser-only formatter for JSON and XML.

Features

• Automatic JSON/XML detection
• Dark and light themes with a saved browser preference
• Format JSON and XML in one large editor
• Word-wrap toggle for long lines
• Fast editor for multi-megabyte payloads (CodeMirror 6): line numbers, syntax colors, undo, and a search box with match count (Ctrl/Cmd+F)
• Copy, Paste, and Delete actions
• Payload history: roll back/forward through previously pasted payloads
• Payload windows: named tabs for juggling multiple payloads (double-click to rename)
• Best-effort formatting for escaped, nested, and irregular JSON/XML input
• Keeps a small draft in the current browser tab across refreshes
• Runs entirely in the browser; no payload is uploaded
• Static files only, so it works directly on GitHub Pages

Run locally

Open index.html through any local static HTTP server. Module workers do not run reliably from file:// URLs.

Editor bundle

The text editor is CodeMirror 6, pre-bundled into vendor/codemirror/codemirror.js so the site needs no build step. After changing vendor/codemirror/entry.js or the pinned versions in package.json, rebuild it:

npm run vendor:codemirror

Test

npm test

Publish with GitHub Pages

This repository is intentionally build-free. Put these files on the main branch, then in Settings → Pages choose Deploy from a branch, select main and /(root).

The site uses relative asset paths so it also works as a GitHub Pages project site under /<repository-name>/.