FileGizmo — Developer tools
Format and validate JSON
Validate, pretty-print, compact, and optionally sort JSON object keys locally.
Simple by design
JSON formatter in three steps
Validate and format JSON without uploading API responses, configuration, test fixtures, or private data. Choose two-space or four-space indentation for readable output, or compact mode for transport and storage. Optional recursive key sorting creates predictable object ordering while preserving values and array order.
Invalid syntax produces the browser parser’s specific error rather than returning partial output. A 2 MB input guard protects responsiveness and encourages huge datasets to be handled with dedicated streaming tools. Formatting parses and serializes JSON, so insignificant source whitespace and original object-key formatting are intentionally replaced.
Everything runs in the current browser page with no account, saved history, or server request. The result is shown in a read-only monospace editor and can be copied immediately. Use formatted output for debugging and review, but remember that JSON object key order should not be treated as semantic application behavior.
- 1
Paste JSON into the editor
- 2
Choose indentation and optional key sorting
- 3
Validate format and copy the result
Good to know
Frequently asked questions
Does FileGizmo modify values?
Values and array order remain intact; optional sorting changes object-key order only.
Is JSON uploaded?
No. Parsing and formatting happen directly in your browser.
What is the input limit?
The formatter accepts up to 2 MB per operation to protect page responsiveness.
Can it create compact JSON?
Yes. Choose compact indentation to remove unnecessary formatting whitespace.
Learn more