ToolBirch

Random String Generator

Secure random strings from letters, digits or hex alphabets.Generators

Random String Generator

Secure random strings from the character set you choose — handy for tokens, ids and test fixtures.

About this tool

Test fixtures, API keys for local development and temporary identifiers all come from the same place: a secure alphabet sampler. Pick the alphabet and length, generate a batch, and copy them out.

How to use the Random String Generator tool

  1. Choose length and alphabet. 1–256 characters from four common character sets.
  2. Pick the batch size. One, five, ten or fifty strings per click.
  3. Generate and copy. Copy the whole batch or use them one at a time.

Supported formats

Input

  • Length between 1 and 256
  • One of four character sets
  • A batch size

Output

  • A list of random strings

Inputs are validated before anything is processed. Invalid values and unsupported files are rejected with a clear error instead of failing silently.

Frequently asked questions

Which alphabets are offered?

Letters plus digits, hexadecimal (lowercase), letters-only, and digits-only.

Is this suitable for API keys?

For local development, yes. Production secrets should come from a vetted secrets manager.

Is the randomness cryptographic?

Yes — the same WebCrypto source as the password generator.

Can I add my own characters?

The four presets cover common needs; custom alphabets are not supported.

Privacy

Everything you enter stays in this browser tab. There is no upload endpoint for tool inputs, no account, and no server-side copy of your text or files. Results are produced locally and disappear when you close the page.

No account is required and no file is ever uploaded. See the privacy policy for details about analytics and the limited data this site stores.

Known limitations

  • Fixed alphabets; no custom character sets.
  • No guaranteed uniqueness across a batch (add a dedupe pass if needed).
  • Maximum length is 256 characters per string.

Related tools

Other free tools from the same collection.

Password GeneratorStrong passwords from the browser's cryptographic random source.Random Number GeneratorCryptographically secure integers in any range, unique if needed.UUID GeneratorGenerate RFC 4122 version 4 UUIDs using cryptographic randomness.Hash GeneratorCompute SHA-1, SHA-256, SHA-384 and SHA-512 digests of any text.