LazyTools

🔒 Every tool runs in your browser — the files and values you enter are never uploaded to any server. How it works

📤 Base64 to File Decoder

Paste Base64 text or a full data URI and get the original file back as a download — decoded locally, never uploaded.

Paste raw Base64 or a full data: URI and get the original file back. If you paste a data URI, its MIME type is detected automatically; otherwise pick a file name with the right extension. 🔒 Decoding runs entirely in your browser — nothing is uploaded.

Rate this tool:
Anonymous — no account, no identifier

How the base64 to file decoder works

The tool takes your Base64 (raw, or a complete data:<mime>;base64,… URI) and reverses the encoding back into the original bytes, then hands you a download. If you paste a data URI, it reads the MIME type from it automatically; for raw Base64 you choose a file name with the right extension. Whitespace and line breaks in the input are ignored, so pasted blocks work fine.

This is the inverse of the File-to-Base64 encoder — useful when an API response, config file or email embeds a file as Base64 and you need the real file back. Only standard Base64 (and base64 data URIs) are supported; URL-encoded or other non-base64 data URIs aren’t files in disguise. Everything is decoded in your browser, so sensitive payloads stay on your device.

Frequently asked questions

How do I convert Base64 back to a file?

Paste the Base64 text (or a full data: URI), set a file name with the correct extension, and click Decode & download. The tool reconstructs the original bytes and saves them.

Do I need to include the data: prefix?

No — both work. If you paste a complete data:<mime>;base64,… URI the MIME type is detected automatically; if you paste raw Base64, just give the download a file name with the right extension (e.g. .png, .pdf).

Why does decoding say my input is invalid?

The text isn’t valid Base64 — usually because characters are missing, extra text was copied in, or it’s a non-base64 (e.g. URL-encoded) data URI. Copy the full, unbroken Base64 and try again.

Does it handle line breaks in the Base64?

Yes — whitespace and newlines are stripped before decoding, so multi-line Base64 blocks paste in without a problem.

Is my data uploaded?

No — decoding runs entirely in your browser and the file is generated locally, so nothing is transmitted and it works offline.

Related file converters

From the blog