# Unicode.UTF8 ``` @frozen enum UTF8 ``` ## Topics ### Structures [`struct ForwardParser`](/documentation/Swift/Unicode/UTF8/ForwardParser) A type that can be used to parse `CodeUnits` into `EncodedScalar`s. [`struct ReverseParser`](/documentation/Swift/Unicode/UTF8/ReverseParser) A type that can be used to parse a reversed sequence of `CodeUnits` into `EncodedScalar`s. [`struct ValidationError`](/documentation/Swift/Unicode/UTF8/ValidationError) The kind and location of a UTF-8 encoding error. ### Type Aliases [`typealias CodeUnit`](/documentation/Swift/Unicode/UTF8/CodeUnit) The basic unit of encoding [`typealias EncodedScalar`](/documentation/Swift/Unicode/UTF8/EncodedScalar) A valid scalar value as represented in this encoding ### Type Properties [`static var encodedReplacementCharacter: Unicode.UTF8.EncodedScalar`](/documentation/Swift/Unicode/UTF8/encodedReplacementCharacter) A unicode scalar value to be used when repairing encoding/decoding errors, as represented in this encoding. ### Type Methods [`static func decode(Unicode.UTF8.EncodedScalar) -> Unicode.Scalar`](/documentation/Swift/Unicode/UTF8/decode(_:)-swift.type.method) Converts from encoded to encoding-independent representation [`static func encode(Unicode.Scalar) -> Unicode.UTF8.EncodedScalar?`](/documentation/Swift/Unicode/UTF8/encode(_:)) Converts from encoding-independent to encoded representation, returning `nil` if the scalar can’t be represented in this encoding. [`static func isASCII(Unicode.UTF8.CodeUnit) -> Bool`](/documentation/Swift/Unicode/UTF8/isASCII(_:)) Returns whether the given code unit represents an ASCII scalar [`static func isContinuation(Unicode.UTF8.CodeUnit) -> Bool`](/documentation/Swift/Unicode/UTF8/isContinuation(_:)) Returns a Boolean value indicating whether the specified code unit is a UTF-8 continuation byte. [`static func transcode(FromEncoding.EncodedScalar, from: FromEncoding.Type) -> Unicode.UTF8.EncodedScalar?`](/documentation/Swift/Unicode/UTF8/transcode(_:from:)) Converts a scalar from another encoding’s representation, returning `nil` if the scalar can’t be represented in this encoding. [`static func width(Unicode.Scalar) -> Int`](/documentation/Swift/Unicode/UTF8/width(_:)) Returns the number of code units required to encode the given Unicode scalar. ### Default Implementations [UnicodeCodec Implementations](/documentation/Swift/Unicode/UTF8/UnicodeCodec-Implementations) ## Relationships ### Conforms To [`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable) [`UnicodeCodec`](/documentation/Swift/UnicodeCodec) [`Escapable`](/documentation/Swift/Escapable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Sendable`](/documentation/Swift/Sendable) [`Copyable`](/documentation/Swift/Copyable) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)