Encode text to standard or URL-safe Base64, or decode Base64 back to UTF-8 text.
Base64 File Converter
Runs locally
Use Base64 File Converter
What it does
Drop or choose a file to get it as a Base64 data URI, or paste a data URI to decode it back into a downloadable file.
It runs entirely in your browser: nothing you enter is uploaded.
Example
A small image
A small PNG file, dropped onto the box or chosen by clicking itdata:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==
Original: 0.1 KB | Base64: 0.1 KB (35% overhead)The box below fills with data:image/png;base64,... and a line shows the original size, the Base64 size and the overhead: Base64 is about a third larger than the file.
FAQ
What does it produce?
A data URI of the form data:type;base64,data, using the MIME type your browser reports for the file. Base64 makes the data about a third larger, and it is an encoding anyone can reverse, not encryption.
Why does Decode & Download do nothing?
It only accepts a one-line data URI with a single MIME type, such as data:image/png;base64,...; extra parameters like ;charset=utf-8, line breaks or invalid Base64 make it fail without a visible message. Files decoded from phishing attachments can be harmful, so check them with File Type Sniffer before opening.
Is the file uploaded?
No. The file is read with the FileReader API and the data URI is built on this page; nothing is uploaded. There is no size limit, so very large files can freeze the tab.