Best JSON formatter: five picks, from browser to terminal

The best JSON formatter for most developers is one that is free, opens instantly and never ships your data to someone else's server. AyeTab's JSON Formatter is our top pick on all three counts, and the others below each win in a narrower case.

Pasting a production payload into a formatting site is one of those habits developers rarely think about until someone asks where that text went. Here is a short list that sidesteps the question.

1. AyeTab JSON Formatter: best overall

AyeTab's formatter beautifies, validates and minifies JSON in the browser. Paste the text and it is formatted and checked straight away. Minify collapses it back to one line, and a status line shows lines and bytes.

The reason it tops the list is where the work happens. The JSON is parsed in your tab and is not uploaded, there is no account, and the page keeps working offline after it loads. It is free, with no watermark on the output.

It also comes as a Chrome extension that takes over the new tab page, so the formatter is always one Ctrl+T away, with a side panel and a Ctrl+K command palette for the rest of the toolbox. Get AyeTab here if that sounds like your workflow.

2. Your editor's format command: best for files

If the JSON is already a file in your project, do not copy it anywhere. VS Code formats a JSON document with Shift+Alt+F on Windows, Shift+Option+F on a Mac and Ctrl+Shift+I on Linux, or Format Document from the right-click menu. Other editors have an equivalent.

3. jq: best in the terminal

jq is a command-line JSON processor that pretty-prints by default, so piping output into jq . formats it. It also takes --indent for a custom width, --tab for tabs and -c for compact output. It shines when the JSON comes from curl or a log file and you want to filter it, not only read it.

4. jsonformatter.org: best for tree view and sharing

jsonformatter.org adds a tree view, a choice of 2, 3 or 4 space indents, file upload and download, loading from a URL and conversion to XML or CSV. It also lets you save and share, but its own page says data saved without logging in becomes public, so keep anything sensitive out of that feature.

5. JSONLint: best for a plain validity check

JSONLint is a free online validator that also formats. Paste or type JSON, or give it a URL, and it points to the line where the error is.

Quick comparison

How we chose

We favored tools that are free, need no signup for the basic job and make it clear where your data goes. A formatter is something you use many times a week without thinking, so the default should be the one you never have to think twice about. That is why a tool that says it runs locally leads, and the sites with more features sit lower.