Base64 is an encoding that represents binary data using 64 printable ASCII characters. Common uses: embedding small images in HTML/CSS, transmitting binary data over text-only protocols, storing binary in JSON.

What's URL-safe Base64?

A variant that replaces '+' with '-' and '/' with '_', and omits padding '='. Used in URLs and filenames where these characters cause problems.

Base64 Encoder & Decoder — Free, In Browser, No Upload

Q: Is encoding done locally?

Yes, encoding and decoding use JavaScript's built-in btoa/atob functions and FileReader for files. Nothing is sent to any server.

Frequently Asked Questions

Is encoding private?

Yes. Encoding/decoding uses JavaScript's built-in btoa/atob functions and FileReader. Nothing is uploaded. Safe for keys, tokens, sensitive data.

Can I encode a file?

Yes — click "Load file" to encode any file as Base64. Useful for embedding small images in HTML/CSS as data URIs.

What's the difference between standard and URL-safe Base64?

Standard uses +/= which can break URLs. URL-safe replaces + with -, / with _, and removes padding. Use URL-safe when the result goes into a URL or filename.