RFC 9285 Base45 encode & decode, as used in EU COVID QR certificates. Base45 Encoder / Decoder is a free online tool from the ToolsRift Encoders & Decoders collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.
Pick Encode or Decode and enter your text. Encoding turns UTF-8 bytes into the RFC 9285 Base45 alphabet; decoding reverses it back to text.
A binary-to-text encoding from RFC 9285 that maps data onto 45 characters (0-9, A-Z, space and a few symbols). It is optimised to pack tightly into QR codes' alphanumeric mode.
Most famously in EU Digital COVID Certificates, where the payload is Base45-encoded before being placed in the QR code.
QR alphanumeric mode has exactly 45 symbols; Base45 uses that full set so two bytes fit in three QR-friendly characters with no waste.