Random Base64 String Generator
Generate cryptographically secure random Base64 strings online with custom byte counts, URL-safe variants, and optional padding removal.
Generate Random Base64 Strings
How to Use the Random Base64 String Generator
- Set how many strings to generate (1–500) and how many random bytes each one should contain (1–1024).
- Optionally enable "URL Safe" to use - and _ instead of + and /, or "No Padding" to remove trailing = characters.
- Click "Generate Base64 Strings".
- Copy individual strings, copy them all, or download them as a .txt file.
Random Base64 String Generator Features
- Uses Web Crypto API (crypto.getRandomValues)
- Custom byte counts from 1 to 1024 with entropy display
- URL-safe alphabet and no-padding options
- Bulk generation with copy and .txt download
Frequently Asked Questions
Are these random strings secure enough for tokens and keys?
Yes. They are generated with the Web Crypto API (crypto.getRandomValues), a cryptographically secure random number generator built into your browser. 16 bytes (128 bits) is a common choice for tokens and IDs, and 32 bytes (256 bits) for secret keys.
How long will each Base64 string be?
Base64 uses 4 characters for every 3 bytes. With padding, the length is rounded up to a multiple of 4, so 16 bytes becomes 24 characters. Without padding, 16 bytes becomes 22 characters. The tool shows the exact length for your settings.
When should I use URL-safe Base64?
Use URL-safe Base64 (RFC 4648 base64url) whenever the string will appear in a URL, filename, cookie, or JWT. It replaces + and /, which have special meanings in URLs, with - and _, and padding is often dropped as well.