Random String Generator
Generate random strings with custom lengths, character sets, and quantities for IDs or testing.
Last updated: May 10, 2026
Generation Options
Output Options
Generated Strings
Random String Generator
A versatile Online Random String Generator for developers, testers, and security professionals. Create unique strings for IDs, testing data, salt values, or placeholder text. You have complete control over the character pool—choose from uppercase, lowercase, digits, and special symbols. Generate thousands of strings instantly, with options for unique results and custom formatting, all processed securely in your browser. Unique mode works out how many combinations your settings allow before it starts: a 12-character string drawn from 62 symbols offers more combinations than you will ever need, but a short length with a small character pool can run dry, in which case the tool reports the shortage instead of quietly repeating strings. Each batch can be laid out one per line or joined with any separator you choose, then copied or downloaded in one click.
Why This Tool Exists
What makes this useful — and why I built it this way.
Developer Ready: Perfect for generating mock data, UUIDs, or unique keys.
Privacy Focused: No data is sent to servers; generation happens on your device.
High Customization: Create exactly the string format your project requires.
Safe Validation: Impossible requests are rejected with a clear message instead of returning duplicate or empty strings.
When You'd Use This
Real situations where this tool saves the day.
Software Testing: Generate large batches of random input data.
Database Mocking: Create unique keys and identifiers.
Security: Generate random salts or temporary tokens.
Content Creation: Create placeholder text or unique serial numbers.
Using Random String Generator
It's straightforward — here's how it works.
Define the length for your random strings.
Select which character types to include (e.g., Uppercase, Digits).
Specify how many strings you want to generate.
Toggle 'Unique Only' if you want to prevent duplicates.
Click 'Generate' to see the results instantly.
Copy individual strings or the entire batch with one click.
Questions People Ask
Honest answers about how this works.
Is this secure for passwords?
Great question. Strings are drawn from your browser's built-in random function, which is fine for IDs, test fixtures, and placeholder text, but it is not a certified random source. For passwords or security tokens, use our dedicated Password Generator instead, which is designed for exactly that purpose.
Can I really include custom characters?
Honestly? The tool ships standard character sets: uppercase A to Z, lowercase a to z, digits, and a pool of common symbols such as at signs, hashes, and brackets. Toggle any of the four off to exclude entire groups, then generate and filter the results if you need finer control.
Will I get duplicates if I run the generator twice?
With Unique Only enabled, duplicates are blocked within a single batch: collisions are retried up to a fixed attempt limit and the tool errors out rather than handing you repeats. Across separate batches nothing is remembered, since results are not stored, so request the full size you need in one run.
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