What is a random string generator used for?

Random strings are used as API keys, tokens, session IDs, salts, coupon codes, file names, and test data. Unlike UUIDs, you control the exact character set and length to match your application's requirements.

Is the output cryptographically secure?

Yes. The generator uses crypto.getRandomValues(), not Math.random(). This is safe for generating tokens, salts, and session IDs. For passwords, also see the Password Generator.

What character sets are available?

Alphanumeric (A-Za-z0-9), uppercase only, lowercase only, numeric only, hexadecimal (0-9a-f), and a fully custom set you define. You can also mix multiple presets.

Can I exclude ambiguous characters?

Yes. Enable "Exclude similar characters" to remove 0, O, 1, I, and l, which reduces transcription errors when the string must be typed manually.

What is the maximum length and batch size?

Each string can be up to 4096 characters. You can generate up to 1000 strings per batch. Very long strings in large batches may take a moment to render.

Can I generate a hex token for an API key?

Yes. Select the "Hex" charset and set the length to 32 or 64 characters. A 32-character hex string has 128 bits of entropy — equivalent to a UUID v4.

How do I use my own character set?

Select "Custom" from the charset dropdown, then type any characters you want in the input that appears. Duplicate characters in the set increase their probability of appearing.

Are generated strings guaranteed to be unique in a batch?

No, but with sufficient length they are effectively unique. For guaranteed uniqueness, use the UUID Batch Generator or reduce batch size relative to the charset range.

Generators /

Random string generator

Generate random strings with any character set and length. Useful for API keys, tokens, session IDs, coupon codes, and test data.

100% in your browser. Strings generated locally, nothing sent.

Character set

Length

Count

Exclude similar characters (0 O 1 I l)

Output

How to use

Pick a character set from the dropdown — alphanumeric covers most use cases.
Set the length of each string. 32 characters hex gives 128 bits of entropy.
Set the count for batch generation (up to 1000).
Optionally enable Exclude similar characters for human-readable codes.
Click Generate, then Copy all to use in your project.

Common use cases

API keys — 32-char hex, prefix with your app name for readability.
Session tokens — 64-char alphanumeric for stateless JWT alternatives.
Coupon codes — 8-char uppercase, no-similar, batch of 100.
Password salts — 16-char hex, one per user record.
File names — 12-char alphanumeric to avoid collisions in upload directories.

Also see: UUID Batch Generator for RFC-compliant unique IDs, Password Generator for human-readable passwords.

Preguntas frecuentes

What is a random string generator used for?: Random strings are used as API keys, tokens, session IDs, salts, coupon codes, file names, and test data. Unlike UUIDs, you control the exact character set and length to match your application's requirements.
Is the output cryptographically secure?: Yes. The generator uses crypto.getRandomValues(), not Math.random(). This is safe for generating tokens, salts, and session IDs. For passwords, also see the Password Generator.
What character sets are available?: Alphanumeric (A-Za-z0-9), uppercase only, lowercase only, numeric only, hexadecimal (0-9a-f), and a fully custom set you define. You can also mix multiple presets.
Can I exclude ambiguous characters?: Yes. Enable "Exclude similar characters" to remove 0, O, 1, I, and l, which reduces transcription errors when the string must be typed manually.
What is the maximum length and batch size?: Each string can be up to 4096 characters. You can generate up to 1000 strings per batch. Very long strings in large batches may take a moment to render.
Can I generate a hex token for an API key?: Yes. Select the "Hex" charset and set the length to 32 or 64 characters. A 32-character hex string has 128 bits of entropy — equivalent to a UUID v4.
How do I use my own character set?: Select "Custom" from the charset dropdown, then type any characters you want in the input that appears. Duplicate characters in the set increase their probability of appearing.
Are generated strings guaranteed to be unique in a batch?: No, but with sufficient length they are effectively unique. For guaranteed uniqueness, use the UUID Batch Generator or reduce batch size relative to the charset range.

Reportar un problema con esta herramienta