Is my file uploaded anywhere?

No, encoding and decoding happen entirely locally using the browser's FileReader API.

What file types are supported?

Any file type — images, PDFs, archives, and more, up to the tool's size limit.

Can I decode a raw Base64 string without a data URI prefix?

Yes, plain Base64 is decoded too and defaults to an application/octet-stream file.

How do I get the decoded file back?

Use the Download file button once a valid Base64 or data URI is pasted.

Does it work offline and on mobile?

Yes. Once the page has loaded it keeps working without a network connection, and the layout is responsive so it stays usable on phones and tablets.

File Base64 Encoder/Decoder

Convert any file to a Base64 data URI, or decode Base64 back to a file.

Support

Works Offline

Privacy First

No Login

No API

FileReader

Upload a file

Drop a file here

Any file type, processed entirely in your browser

Data URI (Base64)

About the File Base64 Encoder/Decoder

Drop any file to instantly get its Base64-encoded data URI, or paste a data URI or raw Base64 string to decode it back into a downloadable file with its detected MIME type and size — all processed locally in your browser.

Examples

Encode an image

photo.png

Output

data:image/png;base64,iVBORw0KGgo...

Keyboard shortcuts

Copy the main outputCtrl / ⌘ + Shift + C
Download the resultCtrl / ⌘ + S
Share this toolCtrl / ⌘ + Shift + S
Reset the inputsAlt + R
Open the tool search paletteCtrl / ⌘ + K

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Frequently asked questions

Version 1.0.0 · Updated 2026-08-11 · Runs entirely in your browser