Base64 Encode / Decode Online - Base64 Encoder & Decoder

How to Use

1. Enter the text or Base64 string in the left text area
2. The URL-safe option converts + to -, / to _ and removes padding
3. Click Encode to convert text to Base64
4. Click Decode to convert Base64 back to text
5. Use the copy button to copy the output to the clipboard

Usage Examples

API authentication header:
HTTP Basic auth is "username:password" encoded in Base64.

Data URI scheme:
Base64-encoded images are used in data:image/png;base64,... URLs.

URL-safe encoding:
JWT headers and payloads are encoded using URL-safe Base64.

FAQ

Is data sent to a server?

No. Everything runs in the browser.

Can I encode binary files?

This tool only handles text strings. Binary files are not supported.

What is URL-safe mode?

Defined in RFC 4648, it replaces + with -, / with _, and omits padding =. Used in JWT.

Decoding fails

Verify the input is valid Base64 and that the URL-safe option matches the input format.

Can I encode Japanese text?

Yes. Text is first UTF-8 encoded, then Base64 encoded, so multibyte characters are fully supported.

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