Encode text to URL-safe Base64 format

Encode bytes as unpadded URL-safe Base64.

freeworks offlinenothing uploaded
ToolBase64URL Encode
Input
Output
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Preview

How it works

Bytes become 24-bit groups mapped through - and _ in place of + and /; trailing padding is omitted. The remaining length allows a decoder to restore the missing padding.

  • URL-safe output avoids percent-encoding.
  • Padding omission suits cookies and tokens.

Worked example

Encode for URL
Encode text to URL-safe Base64 (no padding, safe characters)
Input
											Hello, World!
Output
												SGVsbG8sIFdvcmxkIQ

When to use this

JWTs, signed URLs, and WebAuthn challenges encode binary values.

Edge cases

  • Removing non-trailing padding loses length information.
  • Unicode must be converted to UTF-8 bytes first.
  • Base64url is reversible encoding, not encryption.

References