How to Format and Validate JSON Online

Paste your JSON into the editor at jsonformatter.org, then click Format / Beautify to indent it for readability or Validate to check it for syntax errors. The tool runs in the browser on Windows, Mac, Linux, Chrome, Firefox, Safari, and Edge, so there is nothing to install. Use it when you have raw or minified JSON from an API response, a config file, or a log and need to read it, confirm it is valid, or convert it to another format.

Formatting JSON

Paste your JSON into the editor, or use Upload Data to load a .json file.
Pick an indentation level: 2 Tab Space, 3 Tab Space, or 4 Tab Space.
Click Format / Beautify. The tool uses $.parseJSON and JSON.stringify to re-indent the data so it is easy for a human to read and analyze.

The result is a formatted document you can copy, download, or keep working on. If you want the editor to re-beautify as you type, turn on Auto switch.

Choosing an indentation level

Option	Use it when
2 spaces	You want compact output that still reads clearly, common in JS projects
3 spaces	You need a middle ground between compact and wide
4 spaces	You want maximum readability, common in Python and many config files

Validating JSON

Click Validate to check your text. If the JSON is well-formed, it passes; if not, the tool returns error messages that point to the problem so you can fix it.

A common failure is a missing quote around a key or value. The page notes a JSON Format Checker that helps fix missing quotes: click the settings icon (described as looking like a screwdriver) on the left side of the editor to fix the format.

Inspecting the structure

Two views help you navigate complex data:

Tree view — expand and collapse arrays and objects to move through nested data. The tool also shows an image on hover when a value is an image URL.
Graph view — a visual representation of the JSON string that works as a debugger or corrector for arrays and objects.

Use these when a flat formatted block is too long to scan, for example a deeply nested API response.

Minifying, downloading, and converting

Minify / Compact — strip whitespace to produce compact JSON.
Download JSON — save the created or modified JSON and open it in Notepad++, Sublime, or VS Code.
Convert — turn JSON into XML, CSV, or YAML.
Print — print the JSON data.

Your last formatted JSON is stored locally in the browser's Local Storage, so it can act as a lightweight notepad alternative for beautification.

Practical notes

The page lists Save, Recent Links, Login, My Links, and Logout in its navigation, so saving and sharing JSON is part of the workflow. The available material does not state pricing or whether an account is required for these features, so check the site directly before relying on them.
Because 95% of APIs use JSON to transfer data between client and server, this tool doubles as an API response formatter when you paste a raw response.
If you only need to confirm validity, Validate alone is enough; formatting is a separate step.