Base64 Decode

Decode Base64 strings back into readable text, files, or binary data.

About Base64 Decode

If you have a string of seemingly random letters, numbers, and plus or slash characters, it is very likely Base64 - a way of packing binary data into plain text. This decoder reverses that process, turning a Base64 string back into the original file or readable text.

Paste the encoded string or upload a text file containing it. The tool handles standard and URL-safe alphabets, ignores surrounding whitespace and line breaks, and returns the result as text or as a downloadable file depending on the content.

Decoding is common when inspecting JSON Web Tokens, reading data URIs, debugging API responses, or recovering an attachment that was inlined into an email. If decoding fails, the usual causes are missing padding, copied HTML entities, or text that was never valid Base64 to begin with.

Frequently asked questions

How do I know a string is Base64?

It uses only A-Z, a-z, 0-9, + and / (or - and _), is often a multiple of four characters, and may end with = padding.

The decoder says my input is invalid - why?

Common reasons are stray spaces, missing = padding, or pasting something that is not actually Base64.

Can I decode a Base64 image?

Yes. Paste the data after the comma in a data URI, or use the dedicated Base64 to Image tool to download the picture.

Is decoding reversible?

Yes, decoding simply restores the original bytes that were encoded.

Is my data handled safely?

Input is processed over HTTPS and deleted automatically shortly after; still avoid decoding secrets on a shared computer.