URL Safe Base64 Converter
Convert standard Base64 to URL-safe Base64 and back in your browser.
Standard ↔ URL-safe Base64
Standard Base64 uses + and / characters that break inside URLs, so URL-safe Base64 swaps them for - and _. Moving between the two variants by hand is fiddly. This converter switches standard Base64 to URL-safe and back in your browser.
It is exactly what you need when a token or payload has to travel in a URL or filename. Paste a value, pick the direction, and copy the converted result — with padding handled so both forms stay valid.
URL-safe swaps
URL-safe Base64 replaces + and / with - and _ so a token survives inside a URL. Conversion runs in your browser and never uploads anything.
Frequently asked questions
What makes Base64 URL-safe?
+ becomes -, / becomes _, and trailing = padding is dropped, so the string can sit in a URL without encoding.
How do I convert URL-safe Base64 back?
Choose standard Base64. The tool swaps the characters back and restores padding to a multiple of four.
Where is URL-safe Base64 used?
In JWT tokens, URL parameters, and file names.
Related tools
Practical utilities for everyday web development work.