JSON guide
How to Format JSON Online — Free Tool
Minified JSON from logs and APIs is hard to read and easy to break when editing. Formatting adds indentation and line breaks so you can spot missing commas, wrong types, and nested structure. XSular’s JSON formatter validates syntax, highlights errors by line, and can minify again when you are ready to ship.
Paste your JSON into the editor
Copy the raw JSON—from a network response, config file, or clipboard—and paste it into the input panel. If the document is invalid, you will see an error with the line number before formatting runs.
What you'll see Screenshot: Left editor panel with compact one-line JSON; red gutter marker on a line when a trailing comma error exists.
Choose format mode and indentation
Select Format mode and pick 2-space, 4-space, or tab indentation. The output panel updates with collapsible structure and syntax coloring so objects and arrays are easy to scan.
What you'll see Screenshot: Split view with pretty-printed JSON on the right, mode chips showing Format active, indent set to 2 spaces.
Copy or download the result
Use Copy to place formatted JSON back in your editor, or Download to save a .json file. Switch to Minify when you need a single line for an HTTP body; Validate-only mode is available when you only want a pass/fail check.
What you'll see Screenshot: Toolbar with Copy and Download buttons enabled; byte size comparison showing reduction after minify.
Try it now — free online tool
No signup required. Processing runs in your browser.
Keep formatted JSON out of production hot paths if size matters—minify before deploy. For JWT payloads or Base64-wrapped data, decode with our other developer tools first, then paste the JSON here for cleanup.
JSON Formatter, Validator & Minifier
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