Base64 to File Decoder

Base64 decoding is the reverse of encoding — it converts a Base64 text string back into the original binary data. If you have received a Base64-encoded file inside a JSON payload, an email attachment, or an API response, this tool lets you decode and download it as the actual original file.

The tool supports both raw Base64 strings and complete data URLs in the format data:mime/type;base64,... When a data URL is pasted, the MIME type and suggested file extension are detected automatically from the prefix.

Paste your Base64 string or full data URL into the input. If you paste a data URL, the MIME type is read automatically and a matching file extension is suggested. For a raw Base64 string, choose the correct file type from the dropdown so the downloaded file opens in the right application.

Enter a filename, then click Decode and Download. The decoding runs entirely in your browser using the built-in atob function — no data is sent to any server.