How to Use This Tool
Paste any JSON payload into the input pane on the left — an API response, a config file, a log line, whatever needs cleaning up. Click Format to pretty-print it with two-space indentation, or Minify to strip all whitespace down to a single line, which is useful when you need to paste JSON somewhere space-constrained or shave a few bytes off a request body. If the JSON is invalid, the tool tells you exactly what went wrong and roughly where, instead of just failing silently.
Every character you type stays in your browser tab — parsing runs through the browser's built-in JSON.parse and JSON.stringify, so nothing is uploaded to a server, which matters if you're pasting in payloads that contain real customer data or internal API keys.
Why "Just Reading" Minified JSON Is Slower Than It Looks
APIs increasingly return minified JSON by default to save bandwidth, which is great for production traffic but painful to read by eye — a single-line payload with a missing comma or an extra brace can hide a bug for several frustrating minutes of scrolling through unbroken text. Formatting restores the indentation and line breaks that make nested objects and arrays visually scannable, so you can spot structural problems at a glance instead of counting braces.
- Format when you're debugging, reviewing a payload structure, or documenting an API response for someone else to read.
- Minify when you're shipping JSON over the wire, embedding it in a URL parameter, or need to fit it into a size-constrained field.
- Validate first — a single trailing comma, an unquoted key, or a stray single-quote instead of a double-quote is the most common reason JSON.parse throws in production code.
If you're formatting configuration payloads for a server you're also sizing, our Cloud Cost Estimator and Bandwidth & RAM Calculator can help you plan the infrastructure behind the API this JSON came from.