Data Validation Tools

Which data validator checks identifiers?

Use these pages when the value follows a defined identifier format:

• Base64 Validator checks encoded strings, reports the variant and padding details, and processes a bulk list for CSV export.
• UUID Validator checks UUID/GUID strings and reports structure, version, variant, and v1 timestamp details. It also accepts multiple UUIDs as CSV.
• ISBN Validator checks ISBN-10 and ISBN-13 candidates by length, prefix, allowed characters, and checksum. It can convert a valid ISBN-10 to ISBN-13.
• Credit Card Validator checks card-number candidates against allowed characters, length rules, known network prefixes, and the Luhn checksum. Results include masked values and per-record reasons.
• IBAN Validator checks the country prefix, expected length, BBAN structure, and MOD-97 checksum. It reports country details and a reason for each failed record.
• VAT Number Validator checks a VAT number's country prefix, length, and checksum offline. It reports format validity, not registration status.
• MAC Address Validator checks colon, hyphen, Cisco dot, and compact notation. It also checks length, hexadecimal characters, duplicate status, and address flags.

Validate contact and location data

These pages apply format rules to contact details and postal codes:

• Email Validator checks one address or a bulk list for syntax, domain, quoting, length, and character rules. It can review duplicates and run optional heuristic or live public-resolver DNS checks.
• Phone Number Validator & Formatter checks one number or a pasted list, then reports country, number type, validity, and available formatting results. You can copy or download bulk results as CSV.
• Postal Code Validator checks postal or ZIP code format for a selected country or region. Its checks include casing, spaces, length, patterns, and unsupported-region reporting.

Check IP addresses and URLs

• IP Address Validator & Bulk Lookup Tool checks single or multiple IPv4, IPv6, and CIDR-style inputs, then reports validation and classification results. You can copy or download CSV output; lookup details may be unavailable for some inputs.
• URL Validator, Parser & Checker parses one or more URLs so you can inspect the scheme, hostname, path, query parameters, and fragment. Multi-URL results can be copied or downloaded as CSV.

Compare bulk input and results

Several pages accept bulk input, including Base64, UUID, ISBN, credit card, IBAN, email, phone number, postal code, IP address, URL, MAC address, and VAT number validators. The input and output formats vary: UUID Validator accepts multiple UUIDs as CSV, while Phone Number Validator & Formatter, IP Address Validator & Bulk Lookup Tool, and URL Validator, Parser & Checker can copy or download CSV results.

The returned details also vary. ISBN Validator can convert a valid ISBN-10 to ISBN-13. VAT Number Validator reports format validity only, and IP Address Validator & Bulk Lookup Tool may have no lookup details for some inputs.

Choose the right validation category

Start with this branch of Text Tools when the input has a specific format. Match the page name to the value: use URL Validator, Parser & Checker for URL parts, Credit Card Validator for card-number rules, and Postal Code Validator for a postal or ZIP code tied to a selected country or region.

For UUID/GUID strings, use UUID Validator. For an encoded string, use Base64 Validator.

Frequently asked questions