Developer tools
JSON Validator Online
Check whether pasted JSON is valid and show parse errors without sending it to a server.
Privacy note
Your text is processed in your browser. This tool does not store pasted text on a server.
When this tool helps
Use this tool to validate JSON syntax in your browser.
It is intended for quick checks of copied payloads, configuration snippets, examples, and small API responses.
Common cleanup options
Syntax validation
Check whether pasted text is valid JSON and identify parse errors.
Top-level type
Valid input reports whether the top-level value is an object, array, string, number, boolean, or null.
Local validation
Validation runs in the browser and does not upload pasted JSON in the current implementation.
Related workflow
Use this with JSON formatting, minifying, URL decoding, and HTML decoding when cleaning copied payloads.
How to use it
- Paste JSON text.
- Run the validator.
- Check the valid or invalid result.
- If invalid, fix the parse error and run the check again.
Privacy, review, and limitations
The current version processes pasted text in your browser for normal use, and the page explains the tool behavior that is visible in the interface. Review the preview before copying output into another workflow, especially when the source text came from PDFs, spreadsheets, exports, or copied tables.
This validates JSON syntax only and does not check JSON Schema, OpenAPI, or application-specific rules.
A valid JSON document can still contain unsafe, private, or semantically incorrect data.
Parse error wording comes from the browser runtime and may vary slightly between environments.
Frequently asked questions
Can this check whether JSON is valid?
Yes. Paste JSON and run the validator to see whether it can be parsed.
Does it validate against a schema?
No. It checks JSON syntax only. It does not validate custom schemas or API contracts.
What does top-level type mean?
It reports whether the parsed JSON starts as an object, array, string, number, boolean, or null.
Is my JSON uploaded?
No. The current validator runs locally in your browser.
Last updated: May 11, 2026
See the tool in action
How this page is maintained
This tool page is maintained for practical accuracy, clear limitations, browser-based processing behavior, and links to related cleanup tasks. It is intended for everyday text cleanup, not for legal, medical, financial, security, or other high-stakes decisions.
Browser-local processing
The current tool runs in the browser and does not require an account, upload, or server-side text processing for normal use.
Reviewed behavior
Examples, options, and limitations are checked against the actual tool behavior before public pages are added to the site.
Human review still matters
Text cleanup can miss source-specific issues such as broken words, malformed data, or copied table artifacts, so review important output before reuse.
Safe use checklist
- Use sample or non-sensitive text when testing a workflow.
- Check the output preview before copying it into another system.
- Keep confidential, regulated, or customer data inside approved tools.
- Use related tools only when they match the same cleanup task, not to force unrelated edits.