JWT Decoder
Read a JWT’s header and claims, check expiry and verify HMAC signatures locally.
JSON Formatter & Validator
Paste JSON to pretty-print it, find syntax errors by line and column, or minify it for a request body. Nothing is uploaded.
- Free
- No sign-up
- Runs in your browser
Output
How to use the JSON Formatter
- Paste JSON, such as a webhook payload or API response.
- Choose the indentation and whether to sort keys.
- Click Format or Minify.
- Fix any error at the line and column shown.
Monitor what your code does after it ships
Send events to SensaCat’s ingest API and get alerted when jobs, webhooks and multi-step flows stall.
Frequently asked questions
Trailing commas after the last item, single quotes instead of double quotes, unquoted keys, comments, and unescaped quotes or control characters inside strings. JSON allows none of these.
No. The JSON standard has no comment syntax. Some tools accept JSONC or JSON5, but a strict parser such as JSON.parse rejects comments.
No. Formatting and validation run entirely in your browser.
Sorted keys make two JSON documents easier to compare. Don’t sort a payload before verifying a webhook signature; the signature covers the original bytes.
Related tools
Base64 Encoder / Decoder
Encode and decode Base64 and URL-safe Base64, including files and Basic Auth headers.
Webhook Payload Examples
Sample payloads and headers for Stripe, GitHub, Shopify, Slack, Twilio and Zapier.