Random String Generator
Generate random strings of any length with customizable character sets.
No string generated yet
Set your options, then click Generate.
About Random String Generator
Random String Generator creates arbitrary character sequences of any length from 1 to 128 characters. You control exactly which character pools are included — digits (0–9), lowercase letters (a–z), uppercase letters (A–Z), and symbols such as !@#$%^&*. Every string is built by sampling independently from the combined pool, so each character position is chosen without regard to any other position.
Developers reach for this tool when they need placeholder values during testing, unique identifiers for fixture records, nonces for CSRF tokens, or short random slugs for temporary URLs. Unlike a UUID generator — which always produces a fixed 36-character hyphenated format — or a token generator oriented toward opaque bearer tokens, this tool gives you full control over the alphabet and length. That makes it ideal when you need strings that match a custom format, such as alphanumeric-only IDs or digit-only verification codes.
All generation runs entirely in your browser using the Web Crypto API (crypto.getRandomValues), which provides cryptographically strong randomness. Nothing you generate is sent to a server, logged, or stored. The tool is free, requires no sign-up, and has no rate limit — you can generate as many strings as your workflow demands.
Key Features
Cryptographically strong randomness
Every character is sampled using crypto.getRandomValues, the same source browsers use for TLS key material. The output is unpredictable and passes standard statistical tests for randomness.
Fully configurable character pools
Toggle digits, lowercase, uppercase, and symbols independently to build exactly the alphabet your use case requires — no characters you do not want, no missing ones either.
Variable length from 1 to 128 characters
A slider lets you dial in any length precisely. Whether you need a 4-digit PIN, a 32-character token, or a 128-character stress-test value, the control is direct and immediate.
Auto-generates on setting change
The result updates instantly whenever you move the slider or toggle a character type, so you can explore options quickly without clicking Generate repeatedly.
100% client-side, zero data sent
Generation happens inside your browser tab. No network request is made, which means generated strings cannot be intercepted or logged by a third party.
One-click copy to clipboard
A dedicated Copy button transfers the result to your clipboard immediately. Clicking the output field also selects all text for quick manual copying.
How to Use
Set Length
Use the slider to choose the desired string length, from 1 to 128 characters.
Choose Characters
Select which character types to include: digits, lowercase, uppercase, and/or symbols.
Generate & Copy
Click Generate to create a new random string, then use the Copy button to save it to your clipboard.
Example
A 20-character string using all four character pools — digits, lowercase, uppercase, and symbols — showing typical output density and variety.
Length: 20
Character types: digits + lowercase + uppercase + symbolsK7#mPq2!vN9xLr@4Yw0ZCommon Use Cases
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Seeding test databases with unique IDs
When fixtures or factory functions need distinct string identifiers for each record, generate a batch of alphanumeric strings instead of hardcoding values that collide across test runs.
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Generating nonces and CSRF tokens for manual testing
Security testing often requires a fresh single-use value for each request. A 32-character string mixing all four character types gives sufficient entropy for this purpose without the UUID format overhead.
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Creating random slugs for temporary URLs
Short alphanumeric-only strings (lowercase + digits) make readable URL slugs for staging links, share codes, or invite tokens where UUID hyphens would be awkward.
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Producing digit-only verification codes
SMS or email verification flows typically require a numeric-only code. Enable only the digits pool and set the length to 6 or 8 to get a properly formatted verification code.
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Filling form fields with synthetic data during QA
Manual QA passes require diverse input. Generate strings of varying length and character composition to cover edge cases like symbol handling, case sensitivity, and maximum-length validation.