JSON Formatter
Format, validate, and read JSON with a clearer structure.
Your JSON stays on this device.
What the JSON Formatter does
Paste JSON and this Gizlet reads it with your browser’s own JSON parser. Format indents it two spaces per level so the structure is readable; minify strips every space and newline for somewhere that wants one line.
If the document will not parse, it says what is wrong and where, with the line and column of the character that broke it. Your input is left exactly as you pasted it, so nothing is lost while you fix the problem.
When to reach for it
Format when you have been handed JSON with no whitespace and need to actually read it: an API response copied out of a network panel, a log line, a webhook payload, a configuration file someone minified.
Minify for the opposite problem, where a document has to fit somewhere that dislikes newlines, such as an environment variable, a CI setting, or a single-line database column.
What the four actions do
- Format JSON
- Validates the document and rewrites it with two-space indentation, one key per line, in the order the keys were parsed.
- Minify JSON
- Validates the document and removes all optional whitespace, producing the shortest equivalent JSON.
- Copy result
- Copies the output to the clipboard. It stays disabled until there is a valid result to copy.
- Clear
- Empties the input and the result. Nothing is remembered afterwards, since nothing was stored in the first place.
Your JSON stays on this device
Parsing, formatting, and minifying all happen in this page, using the JSON support built into your browser. The text is never sent anywhere, never written to storage, and gone as soon as you close the tab.
That is the point of doing it here: an access token, a customer record, or an internal API response can be tidied up without handing it to someone else’s server.
Common questions about JSON Formatter
Is my JSON sent to a server?
No. The document is parsed and rewritten by this browser. Gizlet is a static site with no endpoint that could receive it, and nothing is stored between visits.
What indentation does Format use?
Two spaces per level, which is the common convention for JSON and what most linters expect. Minify produces the same document with no whitespace at all.
Does formatting change my data?
The values stay the same, but the document is rewritten from the parsed result, so a few things are normalised: 1.0 becomes 1, 1e3 becomes 1000, escape sequences are written in their shortest form, and duplicate keys collapse to the last one that appeared.
Why does it reject my JSON when it looks fine?
It follows the JSON specification exactly, so comments, trailing commas, single-quoted strings, and unquoted keys are all invalid, even though many editors tolerate them. The error message gives the line and column so you can find the character it stopped at.
How large a document can it handle?
There is no fixed limit. Documents of a few megabytes are comfortable; beyond that you are bound by this device’s memory rather than by a quota.