Validate JSON
Check JSON for syntax errors and locate exactly where they are. Runs entirely in your browser, so your data never leaves your device.
0 chars · 0 lines
Output
The result appears here as you type.
How to use Validate JSON
- 1. Paste the JSON to check. Paste the JSON document you are unsure about, whether it is hand-edited config, a saved API response or something a script generated. There is nothing to configure before checking it.
- 2. Read the pass or fail result. The tool attempts to parse the document and reports either a clear valid confirmation or the exact line and column where parsing failed, along with what token the parser found instead of what it expected.
- 3. Fix the reported location. Jump to the line and column named in the error, since JSON parsers stop at the first problem they hit. Correct it, paste the updated text back in, and check again until it validates.
When to use Validate JSON
Validate JSON is for finding out whether a document is syntactically correct before you trust it, and exactly where it breaks if it is not. It parses the input the same way a strict JSON parser would and reports the precise line and column of the first error.
- Debugging a config file that won't load. An application refuses to start and blames its JSON config file without saying why. Pasting the file here usually points straight at a missing comma, an extra comma, or a stray trailing character.
- Checking hand-edited JSON before deploying. Someone manually tweaked a JSON file in a text editor with no linting and you need to confirm it is still valid before it ships in a build or a config bundle.
- Verifying API documentation examples. You are writing docs with example request and response bodies and want to make sure each JSON snippet is actually valid before publishing it for other developers to copy.
- Diagnosing a CI pipeline failure. A build step fails to parse a generated JSON artifact and the error message from the build tool is vague. This tool pinpoints the exact character that broke the parse.
Examples
Find the error in broken JSON
Input
{
"name": "Ada",
"age": ,
}Output
✗ Invalid JSON Line 3, column 10: Unexpected token ','
About the Validate JSON tool
Validate JSON does its work locally, right in the browser. Check JSON for syntax errors and locate exactly where they are. There is no upload step, no queue and no account, and your data never travels over the network.
It belongs to the JSON Tools collection on EditSafely, a set of 90 small, focused JSON utilities that share the same instant, private workspace.
There is nothing to configure. Provide the input and the result appears on its own. A worked example further down the page shows exactly what the tool produces for a real input.
Running locally also makes the tool fast and dependable: results appear as you type or drop a file, there is no server outage that can take it down mid-task, and confidential data can be processed without a second thought.
Frequently asked questions
Does Validate JSON cost anything?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Is it safe to paste sensitive or confidential data?
No data leaves your device. The whole tool is JavaScript that runs inside your browser tab, so there is no upload, no server-side processing and no log of what you did. If you disconnect from the internet after the page loads, it keeps working.
How much text can I process at once?
There is no fixed limit. Because the work happens on your own device rather than on a shared server, the practical ceiling is your machine's memory, which comfortably handles inputs far larger than typical online tools allow.
Do I need to sign up or install anything?
Nothing to install and no account needed. Open the page in any up-to-date browser, including on a phone or tablet, and the tool is ready.
How do I use the result?
The output panel has a one-click copy button, and you can keep refining the input while you work; the result updates in place as you type.