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This package was approved by moderator flcdrg on 4/17/2017.


Guetzli is a JPEG encoder that aims for excellent compression density at high visual quality. Guetzli-generated images are typically 20-30% smaller than images of equivalent quality generated by libjpeg. Guetzli generates only sequential (nonprogressive) JPEGs due to faster decompression speeds they offer.


Note: Guetzli uses a large amount of memory. You should provide 300MB of memory per 1MPix of the input image.

Note: Guetzli uses a significant amount of CPU time. You should count on using about 1 minute of CPU per 1 MPix of input image.

Note: Guetzli assumes that input is in sRGB profile with a gamma of 2.2. Guetzli will ignore any color-profile metadata in the image.

To try out Guetzli you need to build or download the Guetzli binary. The binary reads a PNG or JPEG image and creates an optimized JPEG image:

guetzli [--quality Q] [--verbose] original.png output.jpg
guetzli [--quality Q] [--verbose] original.jpg output.jpg

Note that Guetzli is designed to work on high quality images. You should always prefer providing uncompressed input images (e.g. that haven't been already compressed with any JPEG encoders, including Guetzli). While it will work on other images too, results will be poorer. You can try compressing an enclosed sample high quality image.

You can pass a --quality Q parameter to set quality in units equivalent to libjpeg quality. You can also pass a --verbose flag to see a trace of encoding attempts made.

Please note that JPEG images do not support alpha channel (transparency). If the input is a PNG with an alpha channel, it will be overlaid on black background before encoding.


On Windows

  1. Get a copy of the source code, either by cloning this repository, or by downloading an archive and unpacking it.
  2. Install Visual Studio 2015 and vcpkg
  3. Install libpng using vcpkg: .\vcpkg install libpng.
  4. Cause the installed packages to be available system-wide: .\vcpkg integrate install. If you prefer not to do this, refer to vcpkg's documentation.
  5. Open the Visual Studio project enclosed in the repository and build it.

To install Guetzli, run the following command from the command line or from PowerShell:

C:\> choco install guetzli

To upgrade Guetzli, run the following command from the command line or from PowerShell:

C:\> choco upgrade guetzli


  • legal\VERIFICATION.txt Show
    Verification is intended to assist the Chocolatey moderators and community
    in verifying that this package's contents are trustworthy.
    Package can be verified like this:
    1. Go to
       to download the installer.
    2. You can use one of the following methods to obtain the SHA256 checksum:
       - Use powershell function 'Get-FileHash'
       - Use Chocolatey utility 'checksum.exe'
       checksum32: 7fb69c00a99a9c0fd7e47f4d263b74c68a7e63405fc27784d955895e8b7f2061
       checksum64: bbac41d606c96cc57a94c802e581591647d6e1cfc83a97522509edbd392faeca
    Using AU:
    File 'LICENSE' is obtained from:
  • tools\chocolateyInstall.ps1 Show
    $ErrorActionPreference = 'Stop'
    $toolsDir = Split-Path $MyInvocation.MyCommand.Definition
    if ((Get-ProcessorBits 64) -and $env:chocolateyForceX86 -ne 'true') {
        Write-Host "Installing 64 bit version"
        rm $toolsDir\guetzli_windows_x86_x32.exe
        mv $toolsDir\guetzli_windows_x86-64_x64.exe $toolsDir\guetzli.exe -Force
    } else {
        Write-Host "Installing 32 bit version"
        rm $toolsDir\guetzli_windows_x86-64_x64.exe
        mv $toolsDir\guetzli_windows_x86_x32.exe $toolsDir\guetzli.exe -Force
  • tools\guetzli_windows_x86-64_x64.exe Show
    md5: 7C84229746CE891178FF63C790806877 | sha1: F32FEAFE28CE265886CEBBC549221D9A6576C772 | sha256: BBAC41D606C96CC57A94C802E581591647D6E1CFC83A97522509EDBD392FAECA | sha512: A98DD145785963B0CB08D074177515F70D9702239625C3EE10AAFF5F9B27CB2E600A9180489D846A9568C70348B6514B00829DA2B209B40E524D8F6BDB1C3CE6
  • tools\guetzli_windows_x86_x32.exe Show
    md5: C3E0E6E3BEFAE7E98D90BBB2870C8C12 | sha1: E3158260A27561D06AA97F370196AA35A02218AA | sha256: 7FB69C00A99A9C0FD7E47F4D263B74C68A7E63405FC27784D955895E8B7F2061 | sha512: 4B7BE7681B5F6FD8EAD8A853E4B88C219DE99F9E3E2586556FB1C340B21415D7E2C14EFDABD82FE9DD687B3807F23E630AD1C804B69C57C5E1E4F7082261EE65
  • legal\LICENSE

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Package Maintainer(s)

Software Author(s)

  • Google


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