Encode / Decode / Preview

Base64 Everything.

Encode text or files to Base64. Decode Base64 back to text or downloadable files. Preview data URLs. Switch between standard and URL-safe variants. Everything runs in your browser — your files never upload.

standard Base64 • no line wrap
Plain text
0 chars0 bytes (UTF-8)
Base64
0 chars
File
Base64
0 chars
Base64 or data URL
0 chars
Preview
Preview will appear here.
Images, PDFs, and text all render.
Binary files offer a download.
Pairs well with
JWT Decoder — decodes the Base64-URL halves of a JWT Favicon Foundry — bundles a favicon as inline data URLs JSON Fixer — if your Base64 is inside JSON, unpack it first

What is Base64?

Base64 turns arbitrary bytes into 64 printable characters (A–Z, a–z, 0–9, +, /). Every 3 input bytes become 4 output characters, which is why Base64 always expands data by ~33%. It exists because many text-based protocols (email, URLs, JSON) can’t handle raw binary — so you encode the bytes, send the text, and decode on the other end.

The URL-safe variant (RFC 4648 §5) swaps + for -, / for _, and strips the trailing = padding. It’s used in JWTs, cookie values, filenames, and anything where the standard alphabet would need escaping. The tool handles both; flip the toggle above.

Base64 is not encryption. Anyone with the Base64 string can decode it back to the original bytes. If you need to hide data, you need real encryption — Base64 is just a transport format.

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