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Validate Checker

Paste text and validate it as JSON, XML, CSV, Base64, UUID, email, URL, or IPv4. Use Auto to detect common formats fast, with a compact pass/fail result and a short error message when something breaks.

Category: Data · URL: /tools/validate-checker.html
Privacy: runs locally in your browser. No uploads, no tracking scripts.

How to use

Use this to validate quick snippets without sending data anywhere.

  1. Paste data into the input.
  2. Select a mode (Auto, JSON, XML, CSV, Base64, UUID, Email, URL, IPv4).
  3. Click Validate to get a pass/fail report.
  4. If using CSV, set the delimiter (comma by default).
Keywords this page targets (natural cluster): validate checker, online validate checker, validate json online, xml validator online, csv validate columns, check csv format, base64 validator, check if uuid is valid, email address validator, url validator online, ipv4 address validator, auto detect json xml csv, find json parse error line, xml parse error checker, csv quote error checker, validate string format, data format validator, syntax validator online, quick validation tool
Secondary intents covered: Check whether pasted text is valid JSON, XML, or CSV, Find where a JSON parse error happens (with a short hint), Verify CSV has consistent column counts and valid quoting, Validate common identifiers like UUIDs and IPv4 addresses, Validate Base64 input before decoding/using it, Quickly confirm whether a string is a valid email or URL, Auto-detect a likely format to save time, Copy a compact validation report to share or log

FAQ

What does this validate checker support?

It validates JSON, XML, CSV, Base64, UUID, email, URL (http/https), and IPv4.

Does Auto-detect change my data?

No. It only tries common parsers and reports the first likely match or a clear failure.

Can it show an exact JSON error line?

Browsers often include position details in the JSON error message; the report shows that message as-is when available.

How strict is the CSV validation?

It checks consistent column counts and proper quoting (including escaped quotes). It doesn’t validate data types.

Is this tool offline/private?

Yes. The validator runs in your browser and does not send input to a server.

Why does URL validation reject some links?

This checker considers only http/https URLs valid to avoid treating non-web schemes as “valid URLs” for typical use.

What if my input is huge?

Very large inputs can be slow in any browser; try validating a smaller slice to locate the issue, then re-check the full data.