Paste JSON, YAML, or a JavaScript object — it's detected automatically.
JSON / YAML / JavaScript

JSON / YAML Formatter

Format, beautify, and convert between JSON, YAML, and JavaScript — turn a JSON payload into YAML and back, or clean up a hand-written JS object. Auto-detects the input format. Private, in-browser, no account.

How it works

  1. Paste JSON, YAML, or a JavaScript object into the input panel — the format is detected automatically.
  2. Pick the output format: JSON, YAML, or JavaScript.
  3. Copy the beautified, converted result. Everything runs in your browser — nothing is uploaded.

Key features

  • Auto-detects JSON, YAML, and JavaScript object literals
  • Beautify and convert between all three formats
  • Distinguishes valid JavaScript ({ x: 2 }) from strict JSON ({ "x": 2 })
  • Invalid input is never silently converted — it's flagged instead
  • Free, private, no account required

Common uses

  • Convert a JSON API response into readable YAML config, or the reverse
  • Clean up a hand-written JavaScript object into valid JSON
  • Beautify a minified JSON payload to inspect it
  • Normalize a file's formatting before comparing two versions

Frequently asked questions

How do I compare json / yaml formatter online?

Paste JSON, YAML, or a JavaScript object into the input panel — the format is detected automatically. Pick the output format: JSON, YAML, or JavaScript. Copy the beautified, converted result. Everything runs in your browser — nothing is uploaded.

Are my files private when I use this tool?

Yes. All comparison runs locally in your browser. Your files never leave your device and are never sent to any server — not a policy promise, but an architectural fact. There is no server receiving your data.

No AI means no hallucinations

Compare Files uses a deterministic, logic-based engine — not a language model. It reports every change that is actually in your files, and never invents one.

Private

Your files never leave your device. Everything runs in your browser — no uploads, nothing stored.

Certain

No AI, so no hallucinations. A deterministic engine reports every real change and never invents one.

Fast

No upload, no server wait. Comparisons run locally and keep working offline once the page has loaded.