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Base64 Encoder / Decoder – Free Online Tool
★ 4.8
(193 votes)Instantly encode and decode complex Base64 architectures online natively. Specifically supports structural Unicode text, raw file parsing, and data URIs.
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