Base64URL decode
Decode a Base64URL string — the URL-safe variant used in JWTs and URLs — back to text. Free online decoder.
Base64URL is the URL-safe Base64 variant used in JWTs and URLs: it swaps + and / for - and _ and usually drops padding. Paste one here to decode it back to the original text.
Why standard Base64 fails on it
A normal Base64 decoder chokes on - and _ because it expects + and /. Base64URL uses the URL-safe alphabet and often omits the = padding, so it needs a decoder that understands the variant — feeding it to a standard decoder produces errors or garbage.
Where you meet it
The header and payload of every JWT are Base64URL. So are many signed URL parameters and tokens. Decoding a JWT part with Base64URL reveals the JSON inside; remember it is not encrypted, just encoded.
Try it now — free, no signup
Use the Base64 tool in your browser. Then, when you need it at scale with an API key and higher limits, grab the full Eveses API.