CNPJ toolsFree
Alphanumeric CNPJ Generator
Generates valid CNPJ numbers for software testing, in the new alphanumeric format (2026) or the current numeric one. Correct check digits, with or without the mask, in bulk and with no sign-up.
- No sign-up
- Runs in your browser
Format
How many
Punctuation
For testing only
The numbers have valid check digits but are random and do not match real companies registered with Receita Federal. Use them in test, QA and development environments, never to impersonate a real CNPJ.
How it works
How the generator builds a valid CNPJ
A valid CNPJ is not just any number: the last 2 digits are check digits, computed from the first 12. To produce a number that passes validation, the tool first draws the 12-position base and only then computes those 2 digits, never the other way around. In numeric mode the base has only digits; in alphanumeric mode it mixes letters (A–Z) and numbers, like the format Receita Federal adopts from July 2026.
The check digits are computed with modulo 11. Each base character becomes a number (digits are 0–9; letters are the ASCII code minus 48, that is A=17 up to Z=42), is multiplied by a weight from 2 to 9 right to left and summed. The remainder of the sum divided by 11 sets each digit. That is why every number generated here passes our CNPJ Validator and any library that follows the specification.
Use the numbers in test environments only. They are statistically valid but random: they belong to no real company and do not appear in Receita Federal records. They are ideal for filling staging sign-ups, testing form rules and validating tax integrations that already need to accept the new alphanumeric format, without using the CNPJ of a real company.
FAQ
Frequently asked questions
How do I generate a valid alphanumeric CNPJ?
Pick the format (alphanumeric or numeric) and the amount, then click generate. The tool draws the 12-position base and computes the 2 check digits with modulo 11, so every generated number passes any CNPJ validation. You can copy it with or without punctuation.
Is the generated CNPJ a real company?
No. The numbers have valid check digits but are random and do not match any company registered with Receita Federal. They are meant to fill test databases, validate forms and stage integrations. Never use them to pose as a real CNPJ.
What is a CNPJ generator for?
For development and QA. Software teams use valid test CNPJs to check input masks, validation rules, document issuing and sign-up forms without exposing real company data. With the alphanumeric format arriving in 2026, generating valid samples helps teams prepare their systems before the switch.
What is the difference between the alphanumeric and numeric CNPJ generated here?
The numeric one uses only digits across the 14 positions, as today. The alphanumeric one allows letters and numbers in the first 12 positions and keeps the 2 check digits numeric, the format Receita Federal starts issuing for new registrations from July 2026. The check-digit math is the same for both.
Is the CNPJ generator free?
Yes, it is 100% free, runs entirely in your browser and needs no sign-up. Generate as many test CNPJs as you need, in bulk, in numeric or alphanumeric format, and copy them one by one or all at once.
Blog
Articles on this topic
Guide
Alphanumeric CNPJ: The New CNPJ Format in 2026
From July 2026, new companies receive a CNPJ with letters and numbers. Understand what changes, why the alphanumeric format was created, how the structure and check digit work, and what to review in your systems before the switch.
11 min read
Guide
How to Validate and Calculate the CNPJ Check Digit
The technical guide to the CNPJ check digit in the alphanumeric format: the modulo 11 algorithm, the character conversion table (ASCII − 48), a worked example step by step and ready-to-use JavaScript to validate numeric and alphanumeric numbers.
9 min read