JSON Validator
Check whether JSON is valid and see syntax errors clearly.
Input is processed in your browser and is not uploaded.
Output
Results appear here.This JSON validator is designed for quick checks before pasting data into code, APIs, or documentation. It reports parse errors immediately and keeps the original text local. Lightweight, mobile-friendly, and built for quick repeat use.
Validate JSON before it reaches an API, test, or document
A JSON document can look correct while one missing quote or extra comma keeps an API request, schema sample, or CI fixture from working. This validator focuses on the parse boundary: it tells you whether the text is valid JSON and where the parser stopped, without rewriting the data in a way that hides the original problem.
Request payload checks
Validate a request body before pasting it into Postman, curl, a fetch call, or API documentation.
Fixture review
Catch broken test fixtures after editing nested objects, arrays, and escaped strings by hand.
Documentation samples
Confirm that examples in README files and integration guides are strict JSON rather than JavaScript-like object literals.
How to debug invalid JSON
- 1Start from the parser error and inspect the character just before it.
- 2Check the surrounding comma, quote, bracket, or escape sequence instead of rewriting the whole document.
- 3Validate again after each small correction so you know which edit fixed the syntax.
- 4Only format or share the JSON after it validates successfully.
Typical validation catch
{"name":"Textbun","private":true,}Invalid JSON: the final comma before } is not allowed in strict JSON.Many editors tolerate JavaScript-style trailing commas, but JSON parsers do not.
Strict JSON reminders
- Keys must be wrapped in double quotes.
- Comments are not part of JSON, even when configuration files look similar.
- Dates, undefined, and functions are not JSON value types; encode dates as strings.
FAQ
What does a JSON validator check?+
It checks whether the text follows JSON syntax, including quotes, commas, brackets, and valid values.
Does it support JSON arrays?+
Yes. Valid JSON can be an object, array, string, number, boolean, or null.
Is this safe for private data?+
Validation happens locally in the browser, so Textbun does not store or upload your JSON.