Base64URL Encoder
What is Base64URL Encoder
Base64URL is the URL-safe variant of Base64. It swaps the two characters that cause trouble in web addresses, + and /, for - and _, and drops the = padding, so the output slots straight into a URL, a filename, or a JWT without any escaping. This encoder converts your text to Base64URL right in your browser, following RFC 4648.
How to use
- Type or paste the text you want to encode.
- Read the Base64URL result in the output box, updated as you type.
- Copy the output or share the link with your text filled in.
- To reverse it, open the Base64URL decoder.
When to use it
Building a token, a query parameter, or a JWT segment and need Base64 that will not break the URL? Encode to Base64URL and you get output with only letters, digits, - and _, and no = padding to percent-escape. It is the encoding inside every JSON Web Token and countless signed links. Decode it back with the Base64URL decoder.
Frequently asked questions
How is Base64URL different from standard Base64?
It uses - and _ in place of + and /, and omits the = padding. Those three characters have special meaning in URLs, so standard Base64 has to be percent-escaped to travel safely, while Base64URL does not. The encoded bytes are otherwise identical.
Where is Base64URL used?
Most visibly in JSON Web Tokens (JWT), where the header, payload and signature are each Base64URL. It also shows up in URL query strings, cookies, filenames and any place a value must survive a URL unescaped.
Why is there no padding?
The = padding character is reserved in URLs, so Base64URL drops it. The length still tells the decoder how many bytes to expect, and this tool re-adds padding internally when decoding, so both padded and unpadded input work.
Is my text uploaded anywhere?
No. Encoding happens entirely in your browser. Nothing you type is sent to a server or stored.
Can I share this with my input pre-filled?
Yes. The URL updates automatically as you type. Copy it from the address bar or use the Copy link button, and anyone who opens it sees your exact input ready to go.
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