JSON Prettifier

Format and pretty-print JSON with proper indentation online. Choose 2 spaces, 4 spaces, or tabs. Instant formatting with error detection and stats.

Indent:

Input JSON

Formatted Output

Why Format JSON?

Paste compressed or messy JSON into the editor and the tool instantly reformats it with proper indentation, line breaks, and syntax highlighting. Formatted JSON is dramatically easier to read, debug, and understand, especially when dealing with deeply nested objects or large API responses.

Most APIs return minified JSON with no whitespace to save bandwidth. While this is efficient for machines, it is nearly impossible for humans to scan. Prettifying the output lets you see the structure at a glance, spot missing fields, verify data types, and trace nested relationships without losing your place.

Indentation Style Conventions

Indent	Characters	Common Usage
2 spaces	Most compact readable format	JavaScript/Node.js projects, npm package.json
4 spaces	More visual separation	Python projects, Java, enterprise codebases
Tab	One tab character per level	Go, some editor defaults, personal preference

Common JSON Formatting Mistakes

The most frequent issues people run into with JSON are trailing commas after the last item in an array or object, using single quotes instead of double quotes around strings, including comments (JSON does not support comments), and leaving keys unquoted.

If your JSON fails to parse, check for these problems first. JavaScript objects allow all of these patterns, but strict JSON does not. A valid JavaScript object like {name: 'test',} with single quotes, an unquoted key, and a trailing comma will fail as JSON. Every key must be in double quotes, every string must use double quotes, and no trailing commas are allowed.

Frequently Asked Questions

What is the difference between 2-space and 4-space indentation?

There is no functional difference. Both produce valid JSON. The choice is purely about readability and convention. Two-space indent keeps deeply nested structures more compact on screen. Four-space indent gives more visual breathing room between levels. Most JavaScript projects use 2 spaces, while Python and Java communities tend to prefer 4.

Does prettifying JSON change the data?

No. Formatting only adds or removes whitespace (spaces, tabs, newlines). The actual data, structure, keys, values, and types remain identical. A minified JSON string and a prettified JSON string parse to the exact same object.

Can I prettify invalid JSON?

No. The tool needs to parse the JSON before it can reformat it. If the input contains syntax errors like trailing commas, single quotes, or unquoted keys, it will show an error message pointing to the problem. Fix the syntax issue first, then prettify.

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