Drop a file here
or pick one below — it never leaves your browser
Encoded or decoded output will appear here.
Encode files to Base64 or restore files from Base64 data.
Encoding and decoding both run locally in your browser via the File and Blob APIs — files and Base64 text never leave your device or touch a server.
A data URI embeds the file's Base64 data directly in HTML/CSS (data:image/png;base64,...), avoiding a separate HTTP request. Best for small files like icons — large files bloat your HTML/CSS instead of caching separately.
Base64 adds roughly 33% overhead — every 3 bytes of binary data become 4 characters of text.
Any file type — there's no restriction on what you select or drop. Images additionally get an inline preview before and after conversion; other file types just show the Base64 and data URI text.
Two: the raw Base64 string and a ready-to-use data URI, shown side by side after encoding so you can copy whichever you need.
No — read and encoded locally in your browser; it never leaves your device.
Yes — switch to Base64 → File, paste the data, and decode it to get a download link plus an inline preview (image thumbnail or text) for the original file.
Yes. If you paste raw Base64 with no MIME type set, the decoded bytes are checked against common file signatures (PNG, JPEG, ZIP, PDF, MP3, and more); if none match, a UTF-8 text check runs instead. A type found only by the text check is marked "guessed from content" since it's less certain than a signature match.