Base64 encode/decode · Guide
Base64 vs Base64url: What Is the Difference?
Base64 and Base64url are nearly identical, differing in just two characters — but that difference matters when the encoded string travels through a URL.
The two different characters
Standard Base64 uses + and /. Both have special meaning in URLs, so Base64url swaps them for - and _, which are URL-safe. Base64url also often omits the = padding.
Where each is used
Standard Base64 appears in email, data URLs and Basic auth. Base64url is used where the value goes into a URL, filename or token — JWT headers and payloads are Base64url-encoded, for instance.
Frequently asked questions
Can I use this for production work?
Yes, for inspection, formatting and quick generation. Still review the output before committing it to production code or configuration.
Ready to try it?
Open the free browser-based Base64 encode/decode and apply what you just read — no sign-up, runs locally.
Open the Base64 encode/decode tool