Random String Generator
Generate random strings from a fully custom character set.
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About this tool
Random String Generator hands you full control: define your own alphabet — maybe unambiguous consonants for readable codes, or a restricted set a legacy system demands — then generate strings of any length in bulk. The tool computes the exact entropy per string from your charset size, so there is no guessing about strength.
Presets for common alphabets (alphanumeric, letters-only, digits) get you started fast. Like everything here, generation uses crypto.getRandomValues and stays on your device.
How to use
- Enter a custom charset or pick a preset.
- Set the string length and quantity.
- Check the entropy readout for your settings.
- Generate, then copy or download the batch.
Frequently asked questions
Entropy = length × log2(charset size). Duplicate characters in your set are deduplicated first, since repeats add no entropy.
Uppercase consonants plus digits, minus ambiguous 0/O and 1/I — e.g. "ABCDEFGHJKMNPQRSTUVWXYZ23456789". Readable over the phone and still strong at sufficient length.
Yes — any characters you type are used verbatim, including symbols and emoji (note that some systems mishandle non-ASCII, so test first).
No. Generation is 100% local to your browser.