Encodeur / décodeur Base64

Encodez et décodez le Base64 pour le texte (compatible UTF-8) et les fichiers, avec une sortie sûre pour les URL. Tout fonctionne localement.

Text

URL-safe alphabet (- and _, no padding)

Result

File to encode (max 10 MB)

MIME type for download

Comment utiliser

Text is encoded as UTF-8, so non-ASCII text works as-is. The URL-safe option replaces + and / with - and _ and drops the = padding. To encode a file, just pick one (10 MB cap) — you also get a ready-made data URL. To turn Base64 back into a file, paste it into the input, set the MIME type and use the download button.

Remarques

Everything is processed in your browser; files are never uploaded. Decoding to text validates the result as UTF-8, so arbitrary binary data may fail with an error — use the download button for binary content instead.

Questions fréquentes

How much larger is Base64 output?

About 33%: every 3 bytes become 4 characters.

Can it decode Base64 with line breaks?

Yes, whitespace is ignored when decoding.