Base45 decode
Base45 decode. Runs on your device, nothing is uploaded.
Base45 decode reads text three characters at a time, each triple unpacking to two bytes, with a leftover pair giving one final byte. Only whitespace at the ends is trimmed, since a space is part of base45's own alphabet, not padding. A lone leftover character, or an overflowing triple, is refused. This is best known from EU health-certificate QR codes.
Questions
Why is only some whitespace stripped?
Because base45's own alphabet includes a space character, so stripping every space would eat real data, not formatting.
How are groups sized?
Three characters decode to two bytes; a leftover pair of characters decodes to one final byte.
What happens with one leftover character?
The tool refuses, since a single leftover character cannot resolve to a byte.
What is base45 used for?
It is best known from EU digital health-certificate QR codes.
Can I use this from the command line?
Yes, the same code runs on the page, the CLI and MCP.