# Format Validator

> Validate emails, UUIDs, IP addresses, credit card numbers, IBANs and semver strings.

To validate a format, paste the value and choose what it should be. The tool checks emails, UUIDs, IPv4 and IPv6 addresses, credit card numbers via the Luhn algorithm, semantic versions, hex colours and URL slugs, explaining exactly which rule failed.

**URL:** https://convertto.tech/t/validator-suite
**Category:** Developer Tools (https://convertto.tech/c/developer-tools)
**Privacy:** Runs entirely in the browser; no upload
**Cost:** Free, no sign-up
**Last updated:** 2026-08-01

## Key facts

- **Privacy:** Runs entirely in your browser — nothing is uploaded
- **Cost:** Free, unlimited, no sign-up

## How to use

1. Enter or paste your value to validate.
2. Choose the validate as.
3. The result appears immediately — copy or download it.

## FAQ

### Why does my valid email fail some validators?

Because most validators implement a simplified rule rather than RFC 5322, which permits quoted strings, comments and characters almost nobody uses. Rejecting a technically valid address is common; the practical answer is to validate loosely and confirm by sending a message.

### Can validation prove data is correct?

Only that it is well formed. A correctly structured IBAN with a valid check digit can still belong to no account, and a syntactically perfect email can bounce. Format checks catch typos, not falsehoods.

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