Secure Random String Generator

The characters it leaves out

Strings are built from 57 letters and digits, with 0, O, 1, I, and l left out because they are easy to confuse when read aloud, written down, or typed from a printout. With no symbols, a string can go into a URL, a file name, or a configuration file without escaping or quoting.

Each character carries about 5.8 bits of randomness, so the default 24 characters give roughly 140 bits and 22 characters are enough for 128, the level usually asked of API keys and session tokens.

When case is ignored

Upper- and lowercase letters are different characters here. If the string will be used somewhere that ignores case, such as an email address, a domain name, or a voucher code typed by customers, count on only about 5 bits per character and make it longer to keep the same strength. For identifiers that need a fixed standard format rather than an arbitrary string, use the UUID generator.

How to use it

1. Choose the options or enter one item per line.
2. Generate a fresh result locally.
3. Copy the result when you are ready.

Privacy & limitations

Inputs and results stay in your browser. This tool does not send list contents or generated values to a server.