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Kitura compression middleware for compressing body data sent back to the client. Supports deflate and gzip compression methods. Uses zlib.

Swift version

The latest version of Kitura-Compression requires Swift 4.0 or newer. You can download this version of the Swift binaries by following this link. Compatibility with other Swift versions is not guaranteed.


Add dependencies

Add the Kitura-Compression package to the dependencies within your application’s Package.swift file. Substitute "x.x.x" with the latest Kitura-Compression release.

.package(url: "", from: "x.x.x")

Add KituraCompression to your target’s dependencies:

.target(name: "example", dependencies: ["KituraCompression"]),

Import package

import KituraCompression

Using Compression

In order to use compression middleware, create an instance of Compression, and connect it to the desired path:

import KituraCompression

router.all(middleware: Compression())

You can configure Compression with optional arguments:

public init (threshold: Int = 1024, chunkSize: Int = 16384, compressionLevel: CompressionLevel = CompressionLevel.defaultCompression, compressionStrategy: CompressionStrategy = CompressionStrategy.defaultStrategy, memoryLevel: Int32 = 8)


  • threshold is the byte threshold for the response body size before compression is considered for the response, defaults to 1024.

  • chunkSize is the size of internal output slab buffer in bytes, defaults to 16384.

  • compressionLevel is the level of zlib compression to apply. The supported values are:
    .noCompression, .bestSpeed, .bestCompression, .defaultCompression

  • compressionStrategy is used to tune the compression algorithm. The possible values are:
    .defaultStrategy, .filtered, .huffmanOnly, .rle, .fixed

  • memoryLevel specifies how much memory should be allocated for the internal compression state. The default value is 8.

For more information on compression parameters, see the zlib manual.

API Documentation

For more information visit our API reference.


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This library is licensed under Apache 2.0. Full license text is available in LICENSE.