Random String Generator
Generate random alphanumeric strings securely online. Free bulk random text generator.
Generated Strings:
How to generate random strings?
Specify the length of the string you want, how many strings you need, and the types of characters to include (uppercase, lowercase, numbers, or symbols). Used as an alphanumeric generator, it's the fastest way to generate random alphanumeric text for tokens or test data. You can even add a custom character set to restrict generation entirely to your specific letters. Click Generate to produce them instantly.
How the randomness works
Each character is drawn using the Web Crypto API's crypto.getRandomValues(), the same cryptographically secure random source browsers use for security-sensitive operations — not the weaker Math.random() that many simple generators rely on. Everything runs locally in your browser, so generated strings are never sent to a server.
Common Use Cases
- Generating unique test IDs, API keys, or coupon codes.
- Creating random tokens for scripts or database seeding.
- Producing placeholder usernames or dummy records for QA testing.
- Generating one-time codes or session identifiers for a prototype.
- Bulk-creating unique reference codes for a spreadsheet import.
Example
Generating a 12-character alphanumeric string might produce something like aZ3kT9mQxP2r.
FAQs
How do I generate random alphanumeric strings online?
Keep "Uppercase Letters", "Lowercase Letters", and "Numbers" checked (and leave Symbols unchecked) to use this as a random alphanumeric character generator — set your desired length and quantity, then click Generate. Since everything runs in your browser, it works as a way to generate string online with no download or sign-up.
Can I restrict output to a custom set of characters?
Yes — enter your own character set in the "Custom Characters" field and the generator will draw exclusively from that combined pool (or from just your custom set if you uncheck the built-in options).
Is this generator cryptographically secure?
Yes. It uses the Web Crypto API's crypto.getRandomValues() rather than Math.random(), so the output has cryptographic-grade randomness — suitable for tokens, API keys, and other secret values, not just cosmetic placeholders.
What's the maximum length and quantity I can generate?
Up to 1000 characters per string and up to 1000 strings in a single batch, all generated locally in your browser with no server round-trip.
What's the difference between this and a UUID generator?
A UUID follows a fixed 36-character format (8-4-4-4-12 hex digits) designed to guarantee global uniqueness across systems. This tool instead produces strings of any length and character set you choose — better suited for custom-length tokens, test data, or codes that need to match a specific format.
Does generating many strings at once risk duplicates?
For any reasonable string length (8+ characters from a mixed character set), the chance of two identical strings appearing even across the maximum batch of 1000 is negligible — each character is drawn independently using a cryptographically secure random source.