File ↔ Base64

Encode a file as Base64 (optionally a data URL) or paste Base64 to reconstruct the file.

Converter Media & Files Updated Apr 19, 2026
How to Use
  1. Drop a file to get Base64 / data URL.
  2. Paste Base64 to reconstruct a file for download.
Encode
Drop file to encode
Any file, any size (memory-permitting)
Decode
Output

Notes

Alphabet
A-Z a-z 0-9 + / =
URL variant
- and _ no padding
Overhead
~33%
Data URL
data:mime;base64,…
Wrap 76
RFC 2045
MIME default.
Privacy
Local

About the File ↔ Base64

File ↔ Base64 is a quick, free tool for image, audio and file tasks. It works in your browser and keeps everything on your device. Encode a file as Base64 (optionally a data URL) or paste Base64 to reconstruct the file.

How it works

Type a value, then pick what you want to change it into. The answer appears straight away. It all happens on your own device, so it is fast and nothing you type is sent away. Just check that you picked the right “from” and “to” so you get the answer you wanted.

Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.

Frequently Asked Questions

Data URL?

data:mime;base64,<payload> — embeddable directly in HTML/CSS.

Size overhead?

~33% bigger than source.

How do I use the File ↔ Base64?

Just type or paste your value. The answer shows up right away — there is no button to press. Change anything and it updates by itself.

Does it cost anything or need an account?

No. The tool is completely free, there is no account to create, and it keeps working offline after the page first loads.

Is anything I type uploaded?

No. The tool works entirely on your device, so the values you enter never leave your browser.

Common Use Cases

Email inline

Embed images in email HTML.

Test fixtures

Inline binary blobs in tests.

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