Validators & Checkers
Free, private validators and format checkers — VAT and tax IDs, IBAN and bank codes, national identity numbers, VIN, accessibility (WCAG), data formats and more. Every check runs entirely in your browser; nothing you enter is uploaded or stored.
Instantly check whether a number or value is structurally valid: VAT numbers and tax IDs by country, IBANs (MOD97), national identity numbers (CPF, Aadhaar, NINO and dozens more), VINs, postal codes, phone formats, and accessibility/data-format rules. Each validator applies the official structure and check-digit algorithm, so you catch typos and bad data before they cause problems.
All validation happens client-side in your browser — the value you paste is never transmitted to a server, stored, or logged. That makes these tools safe for sensitive identifiers like tax, bank and ID numbers.
Start here — our most useful validators & checkers
Hand-picked from the full collection of 7 tools.
Browse validators & checkers by topic
Frequently asked questions
Do these validators send my data anywhere?
No. Every validator runs entirely in your browser using the official format and check-digit rules. Nothing you enter is uploaded, stored or logged — safe for tax, bank and ID numbers.
What does 'valid' actually mean here?
It means the value passes the structural and check-digit rules for its type (length, prefix, checksum). It confirms the format is correct — not that the number is registered to a real, active entity.
Which countries and formats are covered?
VAT/GST numbers, IBANs and national IDs for many countries, plus VIN, postal/phone formats, accessibility (WCAG) and common data formats — each as its own dedicated checker.
Are they free?
Yes, completely free with no account, supported by unobtrusive ads.