Back to Tools
Base64 Encoder / Decoder – Free Online Tool
★ 4.8
(215 votes)Encode and decode Base64 online. Supports Unicode text, file to Base64, image preview, URL-safe mode, and JWT token decoder.
Plain Text
18 bytes
Base64 Output
24 chars
18 B
Original bytes
24
Encoded chars
+33.3%
Size overhead
Standard
Encoding
Base64 encodes every 3 bytes into 4 ASCII characters, adding ~33% size overhead. URL-safe variant replaces + with -, / with _, and removes = padding — used in JWTs, OAuth tokens, and URLs.
All encoding/decoding done in your browser — no data sent to any server