Base45 is a binary-to-text encoding defined in RFC 9285. It packs two bytes into three characters from a 45-symbol alphabet, which is efficient to store in QR codes.

Most notably in the EU Digital COVID Certificate and other QR-based systems, where the 45-character alphabet maps well onto QR code alphanumeric mode.

How are non-ASCII characters handled?

Text is encoded as UTF-8 first, so accented letters, emoji and CJK characters become their byte sequences and decode back exactly.

What happens with invalid Base45?

Decoding checks that every character is in the alphabet and that each group is a valid length and value. Invalid input shows an error instead of broken output.

Base45 Encoder & Decoder

Convert text to and from Base45, the compact encoding (RFC 9285) used in QR codes such as the EU Digital COVID Certificate. Text is processed as UTF-8 bytes, and decoding validates the alphabet and value ranges so malformed input is flagged. Everything runs locally in your browser — nothing is uploaded.

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ModeInput

Output

%69 VD92EX0

How to use

Choose encode (text to Base45) or decode (Base45 to text).
Type or paste your input.
Copy the converted result from the output box.

Frequently asked questions

What is Base45?: Base45 is a binary-to-text encoding defined in RFC 9285. It packs two bytes into three characters from a 45-symbol alphabet, which is efficient to store in QR codes.
Where is it used?: Most notably in the EU Digital COVID Certificate and other QR-based systems, where the 45-character alphabet maps well onto QR code alphanumeric mode.
How are non-ASCII characters handled?: Text is encoded as UTF-8 first, so accented letters, emoji and CJK characters become their byte sequences and decode back exactly.
What happens with invalid Base45?: Decoding checks that every character is in the alphabet and that each group is a valid length and value. Invalid input shows an error instead of broken output.

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