Random Alphanumeric String Generator
Generates a random 12-character string using only letters and digits — no symbols — for placeholder IDs or test data that must avoid special characters.
What this generator does
Produces a random string of letters and digits at the length you choose, for filling identifier fields, reference codes and test inputs where the exact format does not matter.
How to use this tool
- Press generate for a random alphanumeric string.
Worked examples
- Alphabet
- A–Z, a–z and 0–9
Common use cases
- Placeholder IDs that must avoid symbols
- Testing alphanumeric-only input fields
- Sample data for documentation
How this generator works
Characters are drawn independently from the set you choose — letters and digits, with case optional — using the browser's cryptographic source. The entropy follows from the alphabet size: a 62-character set gives just under six bits a character, so a twelve-character string is about 71 bits, which is the figure to compare against whatever you are protecting.
Limitations and good to know
- Not intended as a credential. The password and API key generators exist for that and are excluded from advertising for the same reason.
- Similar-looking characters are all included by default. If the string will be read aloud or typed from a screen, 0 and O, 1 and l are where the mistakes happen.
- A random string is not a password manager. Anything worth generating securely is worth storing somewhere other than a browser tab.
- No structure is imposed, so a result may contain no digits at all — which fails the rules some systems impose on passwords.