✅Validators
Validators check whether a number or document is formally correct: CPF, CNPJ, credit card, Pix key, IBAN, email and more. Validation checks the check digit and the format — it does not confirm that the document exists or belongs to someone. Use them to catch typos in forms and sign-ups.
243 tools
Australian ABN Validator
Validate the format of an ABN (Australian Business Number, 11 digits). Check the registration number of Australian companies before invoicing or trading.
India IFSC Code Validator
Validate the format of an Indian bank IFSC code (4 letters, a 0 and 6 alphanumerics). Check the branch code before making transfers within India.
Tennis Tiebreak Score Validator
Check a tiebreak score such as 7-5 or 10-8: the winner needs at least 7 points and a 2-point margin, and past 7 the gap must be exactly 2.
OAuth Scope Checker
Check whether a requested scope is present in the space separated list a token came back with, matched literally as OAuth 2.0 requires.
JWT Expiry (exp/nbf/iat) Validator
Validate a JWT token timestamps (exp, nbf and iat) and find out if it is expired or not yet valid. Useful for debugging auth, without verifying the signature.
JWT alg Allowlist Policy Checker
Decodes the JWT header, reads its alg field and flags the token when the value is none or absent from the comma-separated list of algorithms you allow.
JWT JTI Format Validator
Validate the format of the JTI (JWT ID), the unique identifier of a JWT token. Check whether it follows security best practices like minimum length and UUID.
client_id / client_secret Validator
Validate the format of an OAuth client_id and client_secret, checking valid characters and minimum length. Useful for debugging auth integrations and APIs.
Bitcoin Address Format Detector
Paste an address and read its script type off the prefix: 1 legacy P2PKH, 3 P2SH, bc1q segwit, bc1p taproot, m, n, 2, tb1 testnet. Prefix only, no checksum.
Ethereum EIP-55 Checksum Inspector
Check an Ethereum address for the 0x plus 40 hex digit format and report whether it carries EIP-55 mixed-case capitalisation, counting the uppercase letters.
Last-Modified Header Validator
Validate whether an HTTP Last-Modified header is in the correct format (HTTP-date, RFC 7231). Useful for debugging browser cache, CDNs and website performance.
HTTP Expires Header Validator
Validate the HTTP Expires header (RFC 7234) and find out how long until the content expires. Useful for debugging cache, CDNs and website performance.
WCAG Keyboard Shortcut Checker
Tests a shortcut against WCAG 2.1.4: a single-character key needs a modifier, a remap or an off switch, while function and named keys fall outside the rule.
Alt Text Length Checker
Check the length of your image alt text against the recommended ~125-character limit. Improve the accessibility and SEO of your website.
Heading Hierarchy Validator
Validate the heading hierarchy (H1 to H6) of a page and find out if it skips levels. Improve the accessibility, structure and SEO of your HTML content.
hreflang vs lang Consistency Checker
Compares the html lang attribute with the main link hreflang value and flags an exact match, the same base language with a different region, or a mismatch.
LGPD Privacy Policy Section Checker
Paste a policy written in Portuguese and see which of 10 sections the LGPD expects are covered: collection, purpose, sharing, rights, cookies, DPO, retention.
ISBN-10 Validator
Validate a book ISBN-10 by computing the mod-11 check digit per the ISO 2108 standard. Useful for libraries, bookstores and older publishing catalogs.
EAN-8 Validator
Validate an EAN-8 barcode (8 digits) by computing the check digit per the GS1 spec. Useful for small products, retail and inventory control.
ITF-14 Validator
Validate an ITF-14 barcode (used on cartons and shipping packaging) by checking the GS1 check digit. Useful for logistics and inventory control.
ISMN Validator
Validate an ISMN (International Standard Music Number), the code for sheet music and printed music, by its check digit. Useful for publishers and music libraries.
SEDOL Validator
Validate a SEDOL code (7 characters) used to identify securities on the London Stock Exchange (LSE), checking the check digit. Useful in international finance.
IMEI Validator (Luhn)
Validate a phone IMEI (15 digits) using the Luhn algorithm. Check whether a device identification number is valid before buying or registering it.
French IBAN Validator
Validate a French IBAN (FR) by checking the 27-character length and the mod-97 check digit. Verify the bank account before sending money abroad.
Italian IBAN Validator
Validate an Italian IBAN (IT) by checking the 27-character length and the mod-97 check digit. Verify the bank account before sending money abroad.
CFOP Validator
Validate a Brazilian CFOP code (fiscal operations code) by checking its 4 digits and prefix. Essential for issuing correct invoices (notas fiscais) in Brazil.
Detailed BIC/SWIFT Validator
Validates BIC format (8 or 11 chars) and extracts bank, country, location and branch — used in international wires.
FIGI Instrument Validator
Validate a FIGI code (Financial Instrument Global Identifier), 12 characters, by its check digit. It is the global asset identifier used in financial markets.
LEI Validator (Legal Entity Identifier)
Validate a 20-character LEI (Legal Entity Identifier) by the ISO 17442 standard — the global company identifier used in financial transactions.
ABA Routing Number Validator
Validate a 9-digit ABA Routing Number used by US banks by checking the official checksum. Useful for transfers, checks and payments in the United States.
NIP Poland Validator
Validate a Polish NIP number (10 digits) with the official checksum. It is the Polish business tax ID — useful for invoicing and trading with Polish companies.
CUIL Argentina Validator
Validates Argentine CUIL (Código Único de Identificación Laboral) with check digit — used in payroll.
PESEL Poland Validator
Validate a Polish PESEL number (11 digits) by its checksum and extract the birth date and sex embedded in it. Useful for Polish records and data validation.
NINo UK National Insurance Validator
Validate a UK National Insurance Number (NINo) by checking the format and prefix/suffix rules. Useful for employment, taxes and sign-ups in the United Kingdom.
Anvisa Drug Registration Validator
Validates Anvisa drug registration code format (13 digits with check digit per the official table).
CNES Health Facility Validator
Validate a Brazilian CNES number (National Registry of Health Facilities, 7 digits). Useful for clinics, hospitals, public health billing and healthcare records.
Anvisa Cosmetic Notification Validator
Validates Anvisa cosmetic notification number format (category + sequential + digit) and extracts the category.
IATA City Code Validator
Validate a 3-letter IATA city code (distinct from the airport code) against the official list. Useful for travel, booking systems and logistics.
MCC (Card) Validator
Validates 4-digit MCC codes used by card networks and shows the category description (e.g., 5411 = Grocery Stores).
Card BIN Validator
Identifies card brand (Visa, Master, Elo, Hipercard, Amex, JCB etc.) and type (credit/debit) from the first 6-8 digits of the card.
ICCID SIM Validator
Validate the ICCID (Integrated Circuit Card Identifier) of SIM chips (19-20 digits) with Luhn digit check and carrier identification.
Dutch BSN Validator
Validate a 9-digit Dutch BSN (Burgerservicenummer) using the 11-test rule. Useful for employment, taxes and data records in the Netherlands.
Italian Codice Fiscale Validator
Validate Italian Codice Fiscale (16 chars, final checksum letter) — used in documents and contracts in Italy.
Peruvian RUC Validator
Validate a Peruvian RUC (11 digits), the SUNAT taxpayer registry number, by checking the checksum. Useful for invoicing and trading with Peruvian companies.
CUID2 Validator
Validate IDs in CUID2 format (collision-resistant, 24 chars, base36, letter prefix), returning whether syntactically valid.
SPDX Expression Validator
Validate SPDX license expressions ("(MIT OR Apache-2.0) AND BSD-3-Clause") with official parser, useful for package.json and Cargo.toml.
EORI (EU) Validator
Validate the format of EORI (Economic Operators Registration and Identification) numbers used in EU customs.
Strict Quartz Cron Validator
Validate Quartz Scheduler cron expressions (6 or 7 fields), supporting ? L W # and ranges. Make sure your Java/Spring schedules are correct.
CAS Number (Chemical) Validator
Validates CAS Registry Number (xxxxxxx-xx-x format) with official checksum used to identify chemical substances.
JMBG (Serbia/Yugoslavia) Validator
Validates JMBG (Jedinstveni Maticni Broj Gradjana) 13-digit personal identifier from former Yugoslavia countries.
BEM Naming Validator
Validate CSS classes against the BEM convention (block, block__element, block--modifier, block__element--modifier) flagging violations.
ICU MessageFormat Syntax Validator
Analyze ICU MessageFormat messages detecting malformed placeholders, plurals missing the other case, missing select branches and invalid types.
Brazilian CBO Code Validator
Validate codes from the Brazilian Classification of Occupations (CBO 2002) with 6 digits, checking major-group/subgroup/family structure.
IMSI Validator (MCC/MNC)
Validate IMSI (International Mobile Subscriber Identity) numbers with 15 digits, breaking down MCC (country), MNC (operator) and MSIN.
YAML Anchor Circular Reference Validator
Detect anchors with circular references (loops) in YAML documents, common in complex Helm/Kubernetes configurations.
SMILES Chemical Notation Validator
Verify SMILES string syntax (atoms, bonds, rings, isomerism, parentheses). Highlights tokenization and valence errors.
EIA-96 Resistor Format Validator
Checks if a string follows the EIA-96 pattern (two digits from table 01-96 + multiplier letter A-Z). Reports specific error.
DUNS Number Format Validator
Validate the 9-digit Dun & Bradstreet D-U-N-S Number, accepting hyphens and spaces. Rejects reserved placeholders like 000000000 and 999999999.
Austrian SVNR Validator
Validates Austrian Sozialversicherungsnummer (10 digits, with weighted check digit) used in SaaS and HR.
Swedish Personnummer Validator
Validate a Swedish personnummer (personal number) with the Luhn algorithm and extract the birth date and gender. Useful for Swedish records and data validation.