Base64URL is a URL-safe variant of Base64 that replaces + with -, / with _, and removes = padding. It is the standard encoding for JWT tokens, URL parameters, and web-safe data transmission.
Standard Base64 contains +, /, and = which have special meaning in URLs. Base64URL eliminates these, making it safe for URL parameters, filenames, and JWT tokens.
Try It Now — Free, No Sign-up
Open the tool and get started instantly. No sign-up, no installation needed.
Open Base64 Encoder & Decoder Now100% browser-based • No upload to server • No sign-up required
How to Base64URL Encode & Decode — URL-Safe Variant
- Paste your text or Base64URL string
- Select Base64URL mode (URL-safe)
- Click Encode or Decode
- Output uses - instead of +, _ instead of /
- No = padding in the output — ready for URLs
Pro Tips
- JWT tokens always use Base64URL — not standard Base64
- Some libraries call this "base64url" or "base64-url-safe"
- To convert standard Base64 to Base64URL: replace + → -, / → _, remove =
- Node.js: Buffer.from(data).toString("base64url") (Node 16+)
Frequently Asked Questions
What is the difference between Base64 and Base64URL?
Base64URL replaces + with - and / with _ (both have special URL meaning). It also removes = padding. The result is safe to use in URL parameters without encoding.
Why do JWT tokens use Base64URL?
JWT tokens are often transmitted in URL parameters and HTTP headers. Standard Base64 characters (+, /, =) would need percent-encoding, making tokens longer and harder to handle.
How to decode Base64URL in JavaScript?
Replace - with +, _ with /, add = padding to make length divisible by 4, then use atob(). Or use Buffer.from(str, "base64url") in Node.js.
Related Tools & Guides
Ready to Use Base64 Encoder & Decoder?
Free, instant, and 100% private. No sign-up needed.
Open Base64 Encoder & Decoder