To Base64

Converts the input to Base64. Use it when you need to send binary data through text-only channels (APIs, email, logs) or when a downstream step expects a Base64 string. Supports multiple alphabets (RFC 4648 standard and URL-safe, plus other common variants). To Base64 lives in the Data format category of the fx menu.

To reverse the encoding, use From Base64.

Parameters

Parameter	Type	Required	Default	Description
Input	binary	yes	—	Raw bytes to encode. Previous step output that provides binary data, or binary-capable input.
Alphabet	string	yes	Standard (RFC 4648): A-Za-z0-9+/=	Defines the 64 Base64 sextet symbols. Use a preset (RFC 4648, URL-safe, Filename safe, and others) or a matching custom alphabet. Encoding and decoding must use the same alphabet. See RFC 4648.

Input is the primary value (previous step output or a literal). Alphabet is an editable preset on the function card.

Returned value

Type	Description
string	The Base64-encoded ASCII string for the input.

Limitations

• Input must be binary (ArrayBuffer). Non-binary input raises toBase64: functionInput must be an ArrayBuffer.
• Alphabet must be a string. Use the same alphabet later with From Base64.
• URL-safe alphabets omit or replace +, /, and padding differently — pick the preset that matches the consumer.

Examples

Encode with the standard alphabet

Encode binary or text-as-bytes into a standard Base64 string — the most common Base64 use in a flow.

1. Set Input to the bytes or text from the previous step.
2. Leave Alphabet on Standard (RFC 4648): A-Za-z0-9+/=.
3. Confirm Output value is a Base64 string (for example hello becomes aGVsbG8=).

Encode with the URL-safe alphabet

Use the URL-safe alphabet when the Base64 string will appear in a URL or filename and you must avoid + and /.

1. Set Input to the bytes to encode.
2. Set Alphabet to URL safe (RFC 4648 §5): A-Za-z0-9-_.
3. Confirm Output value uses - and _ instead of + and / where those sextets appear.