💬 Fast & Lightweight MsgPack Serializer & Deserializer for Swift

What's New

SwiftMsgPack 1.2.0


Released on: 2020-11-15


  • [NEW] #6 Added full Swift 5 support
  • [NEW] #6 Added watchOS 2.x+ support


It's like JSON, but faster!

Carthage compatible CI Status Version License Platform

What's this?

MessagePack is an efficient binary serialization format, which lets you exchange data among multiple languages like JSON, except that it's faster and smaller. Small integers are encoded into a single byte while typical short strings require only one extra byte in addition to the strings themselves.
You can read more about specs directly from the main web site.
Moreover it's made in pure Swift, no dependencies, lightweight & fully portable

Your Support

Hi fellow developer!
You know, maintaing and developing tools consumes resources and time. While I enjoy making them your support is foundamental to allow me continue its development.

If you are using SwiftLocation or any other of my creations please consider the following options:


How to use: one-shot pack & unpack

Both serialization and deseralization happens inside a Data object.

In order to pack one or more objects you need to create an empty Data instance and call pack by passing the object(s) you want to serialize. It's pretty easy, take a look here:

var data = Data()
do {
  let obj1 = "Hello World"
  let obj2 = 45.5
  let obj3: [AnyHashable:Any?] = [ "key_1" : "value test","key_2" : 4,"key_3" : true, otherHashableKey: "value1"]
  // Now you can pack your instances by passing them to pack function
  try data.pack(obj1,obj2,obj3)
} catch {
  print("Something went wrong while packing data: \(error)")

Deserializing data is pretty simple too, just call unpack function to an instance of Data with msgpack data:

let data: Data = // msgpack data...
do {
  let decodedObj: Any? = try data.unpack()
} catch {
  print("Something went wrong while unpacking data: \(error)")

Supported Types

SwiftMsgPack supports the following Swift types:

  • String
  • Data
  • Bool
  • nil
  • Numeric values: Int & UInt (UInt8,Int8,UInt16,Int16,UInt32,Int32,UInt64,Int64), Float and Double
  • Dictionaries ([AnyHashable:Any?])
  • Array ([Any?])

The following limitations are specified by MsgPack specs format:

  • a value of an Integer object is limited from -(2^63) upto (2^64)-1
  • maximum length of a Binary object is (2^32)-1
  • maximum byte size of a String object is (2^32)-1
  • String objects may contain invalid byte sequence and the behavior of a deserializer depends on the actual implementation when it received invalid byte sequence
    • Deserializers should provide functionality to get the original byte array so that applications can decide how to handle the object
  • maximum number of elements of an Array object is (2^32)-1
  • maximum number of key-value associations of a Map object is (2^32)-1


You can install Swiftline using CocoaPods, carthage and Swift package manager


pod 'SwiftMsgPack'


github 'malcommac/SwiftMsgPack'

Swift Package Manager

Add swiftline as dependency in your Package.swift

import PackageDescription

let package = Package(name: "YourPackage",
  dependencies: [
    .Package(url: "https://github.com/malcommac/SwiftMsgPack.git", majorVersion: 0),


SwiftMsgPack has an extensive coverage using XCTest. You can found a complete list of tests inside Tests/SwiftMsgPackTests folder. Tests can also be runned with XCode using the SwiftMsgPack project.


  • If you need help or you'd like to ask a general question, open an issue.
  • If you found a bug, open an issue.
  • If you have a feature request, open an issue.
  • If you want to contribute, submit a pull request.

Copyright & Acknowledgements

SwiftLocation is currently owned and maintained by Daniele Margutti.
You can follow me on Twitter @danielemargutti.
My web site is https://www.danielemargutti.com

This software is licensed under MIT License.

Follow me on:


  • Swift Tools 5.3.0
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Last updated: Thu Nov 23 2023 01:19:46 GMT-1000 (Hawaii-Aleutian Standard Time)