XML & JSON · Formatter · Validator
Format, validate & fix XML and JSON
Paste your code, see the exact line and column of any error in red, and fix it in one click. Everything runs in your browser — private, fast, and free.
🔒 100% private — your document is processed entirely in your browser and is never uploaded, logged, or stored.
Everything you need to clean up markup
Exact error location
Every problem is underlined at the precise line and column — no vague “invalid” messages.
One-click auto-fix
Repair trailing commas, single quotes, unquoted keys, and bare ampersands instantly.
Tree view
Explore the structure of any JSON or XML document with a collapsible tree.
JSON ⇄ XML convert
Convert JSON to XML and back, side by side, with attributes and arrays handled correctly.
Completely private
Everything runs in your browser. Your data is never uploaded, logged, or stored.
Fast & lightweight
A static, near-zero-JS site with one focused editor. It just loads and works.
Free, no sign-up
No account, no paywall, no watermark. Format and validate as much as you like.
Pick your tool
Each tool opens the same fast editor, tuned for the job:
Built to be better than the rest
Plenty of sites will beautify your JSON or XML. Far fewer will tell you exactlywhere it broke and offer to fix it. Indentio combines a professional code editor, precise error reporting, and a proven repair engine into one clean, private, ad-light page — so you spend seconds, not minutes, chasing a stray comma or an unclosed tag.
Frequently asked questions
Is Indentio free?
Yes — completely free, with no account required. It is supported by unobtrusive ads.
Do you store what I paste?
No. All processing happens locally in your browser. Your JSON and XML never leave your device.
What can I format and validate?
JSON and every XML dialect — including SVG, RSS, Atom, XSD, WSDL, and sitemaps.