Use this base45 converter to quickly encode text into the QR-friendly RFC 9285 format, or perform a base45 decode to reveal the original UTF-8 text. The tool operates directly in your browser without uploading any data.
Base45 was specifically built around the QR code alphanumeric character set. It is widely used in systems that need to embed binary data into QR codes efficiently, like the EU Digital COVID Certificate.
The RFC 9285 alphabet
The base45 encoder uses the standard 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./: alphabet. Because it avoids lowercase letters and includes specific punctuation, it works perfectly with QR code alphanumeric mode.
Importantly, the space character is a valid Base45 digit. Be careful when copying or modifying Base45 strings, as removing or changing spaces can completely break the encoded payload.
Line wrapping and formatting
To make long encoded sequences easier to read, you can enable Wrap @ 76. This breaks the encoded output into distinct lines. The base45 decoder ignores these line breaks automatically.
Base45 does not use = padding characters. The final output length is entirely dependent on how the underlying bytes divide into pairs.
Batch conversion and line trimming
If you need to process multiple values, enable Batch by newline. This evaluates every input line separately, making it easy to decode test vectors or encode payload lists.
You can also use Trim lines to strip invisible whitespace from the start or end of each line before conversion. Because spaces are valid Base45 characters, this feature is disabled by default to prevent accidental data corruption.