Online JSON Formatter — Prettify with Custom Indentation

Format minified or messy JSON with readable indentation. Choose 2 or 4 spaces or tabs — all processing stays local in your browser.

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JSON formatter — prettify playbook
Turn minified or messy JSON into readable, indented output. Choose 2 or 4 spaces or tabs — formatting runs locally with no uploads.

Format, beautify, or pretty-print JSON

Searches for a JSON formatter, beautifier, or pretty-printer usually mean the same thing: re-indent minified or single-line JSON so humans can read it. Paste a payload here, pick two or four spaces or tabs, optionally turn on Sort keys, then click Format. Everything runs in your browser—nothing is uploaded to FastMinify. Syntax is checked before output is produced. Invalid JSON does not format; the results panel shows the failure so you can fix the text. For line-and-column feedback while you edit, use the JSON validator. Indentation changes whitespace only (unless Sort keys is enabled). Parsed values stay the same by default. To shrink payloads instead of expanding them, use the JSON minifier.

Developer notes

• Input is validated before formatting — fix syntax errors first (or use the JSON validator tool). • Indent size and character (spaces vs tabs) apply on each Format action. • Data fidelity is preserved: numbers, key order and string contents stay identical. • For byte reduction, use the JSON minifier — this page targets readability, not compression. • The minify-family beautify JSON page shares the same editor UX as CSS/HTML — pick whichever entry point fits your navigation.

Formatting options

Indent size
Number of spaces per indentation level when using spaces (ignored for tabs).
Indent style
Use spaces or a tab character for each indentation level.
Sort keys
Off by default (preserves key order). On recursively sorts object keys for stable diffs; array order is unchanged. For advanced sorting options, use <a href="/en/json-sort">JSON Sort</a>.

When teams pick this route

• Review minified API logs or webhook payloads during incident response. • Normalize fixtures before opening pull requests. • Prepare readable snippets for documentation or Slack threads. • Inspect converter output before exporting to YAML or CSV.

Worked examples

Minified log line

Sample input

{"order":{"id":"ord_8f2a","status":"paid","customer":{"id":"cus_42","name":"Ada Lovelace","email":"[email protected]"},"line_items":[{"sku":"WB-001","qty":2,"price":24.99},{"sku":"WB-003","qty":1,"price":89.0}],"total":138.98}}

Formatted output

{ "order": { "id": "ord_8f2a", "status": "paid", "customer": { "id": "cus_42", "name": "Ada Lovelace", "email": "[email protected]" }, "line_items": [ { "sku": "WB-001", "qty": 2, "price": 24.99 }, { "sku": "WB-003", "qty": 1, "price": 89 } ], "total": 138.98 } }

Nested config with tabs

Sample input

{"metrics":{"cpu":"450m","memory":"512Mi","replicas":3}}

Formatted output

{ "metrics": { "cpu": "450m", "memory": "512Mi", "replicas": 3 } }

Navigate related JSON tools

Browse the JSON tools hub for the full cluster. Validate first with the JSON validator, spot regressions using JSON diff, or explore keys in the JSON tree viewer. Tighten payloads via our JSON minifier or export through JSON → XML.

JSON formatter FAQ

Beautify without changing data

Does formatting change values?

No — only whitespace and indentation change. Parsed data remains identical.

Difference vs JSON minifier?

The minifier removes whitespace to shrink file size. This formatter adds indentation for human review.

Key order?

Insertion order from the parser is preserved in the formatted output.

Server uploads?

No — formatting executes locally in your browser.

Can I sort keys?

This formatter includes a basic Sort keys toggle for quick canonicalization. For full control (natural/numeric order, array sorting, depth limits), use the dedicated JSON Sort tool.

How do I format JSON with 2 or 4 spaces?

Open the Indent control in the options card: choose 2 spaces or 4 spaces, or switch the style to tabs. Each Format action (or auto-format after paste) applies the current indent settings.

What is the difference between a JSON formatter and a validator?

A formatter re-indents valid JSON for readability. A validator checks whether text is valid JSON and reports syntax problems—use the JSON validator when you only need a pass/fail verdict with location hints, then return here to prettify.

JSON Tools

Validate, format, diff and explore JSON payloads — complementary to minifiers and converters.

JSON Validator

JSON Tree Viewer

JSONPath Tester

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JSON Diff

JSON Merge

JSON Sort

JSON Escape

JSON Unescape

JSON → TypeScript

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Count words, build Markdown TOCs, and clean line lists — all in your browser.

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Token counting, pricing estimates, and context-window fit — 100% browser-local.

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Synthetic field values for fixtures and DB seed — reserved-range phone numbers first.

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Draw Code 128, EAN-13, and UPC-A label images in the browser — PNG and SVG download, not a GS1 lookup.