Base64 to File Decoder
Decode a Base64 string and download the original file. Runs entirely in your browser.
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Leave as-is unless you know the original file type. Data URIs auto-detect.
Base64 to File decodes a Base64 string back into the original file and downloads it. ConvertDa's free Base64 to File tool runs in your browser — paste the string, pick a filename, and download. Auto-detects the file type from the data URI prefix.
How to base64 → file
- 1
Paste the Base64 string into the input box.
- 2
Optionally set a filename and MIME type.
- 3
Click Decode & Download.
Frequently asked questions
What if I don't know the MIME type?▾
Leave it as application/octet-stream — the file will still download correctly; only previewing in some apps may differ.
Are data URIs supported?▾
Yes. If your input starts with data:[mime];base64, the tool auto-detects the MIME type.
What if the Base64 string has no data URI prefix?▾
You can still decode it — pick the file extension manually before downloading. Without a prefix the tool can't auto-detect the type, but the decoded bytes are identical.
Will line breaks in the Base64 string break decoding?▾
No. Whitespace and line breaks are stripped automatically before decoding. Standard formatting from email or HTTP headers works as-is.