Base64 Encoder / Decoder

Encode text or files to Base64, or decode Base64 back — with a URL-safe variant option.

Runs in your browser. Nothing is uploaded.

Mode

Input type

URL-safe variant

How to use

Base64 Encoder / Decoder in 3 steps

Choose mode and input type

Pick Encode or Decode, then Text or File as your input.

Provide your input

Type text, paste a Base64 string, or drop a file onto the drop zone.

Run and copy

Click Run. Copy the result or download it as a file.

Features

Why use this Base64 Encoder / Decoder

Works on both plain text and any file type.

Optional URL-safe variant (- and _ instead of + and /) for use in URLs and filenames.

Decoding a file's Base64 gives you back a downloadable file, not just text.

Everything runs locally — nothing is ever sent to a server.

FAQ

Questions about this tool

What is the URL-safe variant for?

Standard Base64 uses + and / characters, which have special meaning inside URLs. The URL-safe variant replaces them with - and _ so the result can be used directly in a URL or filename without extra encoding.

Can I decode a file I previously encoded here?

Yes — switch to Decode mode, paste the Base64 text, and the result downloads as a file rather than displaying as text once decoded.

Why did decoding fail with an error?

This usually means the pasted text isn't valid Base64 — check that no characters were accidentally added or removed, and that the URL-safe toggle matches how it was originally encoded.

Is there a file size limit?

Files are limited to 20MB here since Base64 encoding increases size by about a third and very large files can make the browser tab slow or unresponsive.