Base64 Encoder & Decoder
text · URL · file · live · URL-safe mode
URL-safe mode (replace
+/ with -_, strip =)
Input
Output
Invalid Base64 — could not decode
Base64 Quick Reference
Base64 encodes binary data as ASCII text using 64 characters:
Every 3 bytes of input → 4 Base64 characters. Output is ~33% larger than input.
URL-safe Base64 replaces
Common uses: embedding images in HTML/CSS, JWT tokens, email attachments (MIME), API payloads.
A–Z a–z 0–9 + /Every 3 bytes of input → 4 Base64 characters. Output is ~33% larger than input.
URL-safe Base64 replaces
+ with -, / with _, and strips padding =.Common uses: embedding images in HTML/CSS, JWT tokens, email attachments (MIME), API payloads.