Type Method

encode(_:)

Encodes raw bytes using the URL-safe unpadded Base64 alphabet.

static func encode(_ data: Data) -> String

Parameters

data: The bytes to encode. May be empty; the empty input produces the empty string.

Return Value

A Base64URL string consisting solely of characters from the 64-symbol URL-safe alphabet plus no padding. Round- tripped via decode(_:) to recover the original bytes.

Mentioned In

Discussion

Emits the encoding defined in RFC 4648 §5: the standard Base64 alphabet with + replaced by -, / replaced by _, and the trailing = padding stripped. The output is safe to drop into URL path segments, query parameter values, HTTP header fields, JSON string values, JWS/JWT segments, and filename components without further escaping.

Implementation detail: this is a thin layer over Foundation’s Data.base64EncodedString() followed by alphabet translation and padding removal. It does not call into libcrypto.

Note

Not constant-time with respect to the input length or content. Do not use on side-channel-sensitive material.