Random OTP Code Generator
Generate one time codes of any digit length for testing sign in flows and message templates.
Random OTP Code Generator
6 digit code
How many codes
Code length
How to use the OTP generator
- Choose 4, 6 or 8 digits, with grouping for the easy to read 123 456 style.
- Generate one code or a batch of up to 500 for test fixtures.
- Copy the codes or export them as a CSV.
About Random Nr's OTP Code Generator
The OTP code generator produces one time codes of any digit length, made for testing sign in flows and message templates. Set the number of digits and generate as many codes as you need, and Random Nr draws each one from the browser secure random source, so your test data behaves like the real thing without touching a live system.
How hard is an OTP code to guess
A one time code is safe because of its keyspace and its short life. The keyspace part is exact:
| Code length | Possible codes | Chance of guessing in 3 tries |
|---|---|---|
| 4 digits | 10,000 | 0.03% |
| 6 digits | 1,000,000 | 0.0003% |
| 8 digits | 100,000,000 | 0.000003% |
Six digits is the industry default because at three permitted attempts the guessing odds are already negligible, while the code stays short enough to retype from a phone screen without errors.
Why OTP codes expire after 30 seconds
Real authenticator apps generate codes with the TOTP standard, RFC 6238, which derives a fresh six digit code from a shared secret every 30 seconds. The short window is the second half of the defence: even a leaked code is worthless within a minute. The codes on this page are random rather than secret derived, which is exactly what you want for building and testing the screens, templates and validation around such systems without touching a real secret.
Using OTP codes for testing sign in flows
Batch generate codes to seed message templates, test rate limiting, fill demo screenshots or drive automated tests through verification screens. Grouping renders codes the way apps display them, and the CSV export drops straight into a test harness. For durable codes that live longer than a minute, the PIN generator with its weak code filters is the right tool.
More code and ID generators
Frequently asked questions
What is an OTP
A one time passcode, the short numeric code used to confirm a sign in or a transaction. It is meant to be used once and then discarded.
What lengths are supported
Four, six or eight digits. Six is the most common for authenticator apps and text codes.
Can I generate several at once
Yes, up to 500 codes at a time, ready to copy or export for testing.
Are these real login codes
No. They are random codes for testing and demos. They do not unlock any real account.
Is it free
Yes, free and with no sign up.
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For a personal identification number see the PIN code generator, or a product key with the serial number generator.