XL Converter

Easy-to-use image converter for modern formats. Supports multithreading, drag 'n drop, and downscaling.

Available for Windows and Linux.

Read the Manual

Supported Formats

Encode to JPEG XL, AVIF, WebP, and JPEG.

Features

JPEGLI

Generate fully compatible JPEGs with up to 35% better compression ratio.

JPEG XL and AVIF

Achieve exceptional quality at a modest size with JPEG XL and AVIF.

Parallel Encoding

Encode images in parallel to speed up the process. Control how many threads to use for encoding.

Lossless JPEG Recompression

Losslessly transcode JPEG to JPEG XL, and reverse the process when needed.

Downscaling

Scale down images to resolution, percent, shortest (and longest) side, or even file size.

Building from Source

Note

The recommended way of using XL Converter is through the official binary releases. The building process is time-consuming and tedious.

Windows 10

Install:

• Python 3.11.9 (check Add python.exe to PATH)
• git

Clone the repo.

git clone -b stable --depth 1 https://github.com/JacobDev1/xl-converter.git
cd xl-converter

Provide tool binaries.

Setup venv.

python -m venv env_build
env_build\Scripts\activate.bat
pip install -r requirements.txt

Install redistributable

Run the application

python main.py

You can also build it.

python build.py

Linux (Ubuntu-based)

Install packages.

sudo apt update
sudo apt install git make curl fuse p7z-full

Install xcb QPA dependencies.

sudo apt install '^libxcb.*-dev' libfontconfig1-dev libfreetype6-dev libx11-dev libx11-xcb-dev libxext-dev libxfixes-dev libglu1-mesa-dev libxrender-dev libxi-dev libxkbcommon-dev libxkbcommon-x11-dev

Install pyenv via Automatic installer then add it to shell

Install Python build packages.

sudo apt install wget build-essential libreadline-dev libncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev libffi-dev zlib1g-dev liblzma-dev

Build and setup Python 3.11.9.

pyenv install 3.11.9
pyenv global 3.11.9

Clone and set up the repo.

git clone -b stable --depth 1 https://github.com/JacobDev1/xl-converter.git
chmod -R +x xl-converter
cd xl-converter

Provide tool binaries.

Create and activate a virtual environment.

python -m venv env_build
source env_build/bin/activate

Install Python dependencies

pip install -r requirements.txt

Now, you can run it.

python main.py

or build it.

python build.py

Providing Tool Binaries

To build XL Converter, you need to provide various binaries. This can be quite challenging.

Tip

Use the official builds as a reference.

Libraries:

• libjxl v0.10.2
• libavif v1.0.4 (AOM 3.9.1)
• imagemagick 7.* Q16-HDRI
• exiftool 12.92
• oxipng v0.9.2

Linux (x86_64)

The following static binaries are required:

• libjxl - cjxl, djxl, jxlinfo, cjpegli
• libavif - avifenc, avifdec
• imagemagick - magick (AppImage)
• oxipng - oxipng

Move them to xl-converter/bin/linux.

Windows (x86_64)

The following static binaries are required:

• libjxl - cjxl.exe, djxl.exe, jxlinfo.exe, cjpegli.exe
• libavif - avifenc.exe, avifdec.exe
• imagemagick - magick.exe
• oxipng - oxipng.exe
• ExifTool - folder named exiftool\ with exiftool.exe and exiftool_files\

Move them to xl-converter\bin\win.

Note

libjxl does not feature UTF-8 support on Windows. To enable it, embed this manifest into each EXE with mt.exe from Visual Studio.

Info

Important

This project runs on Python 3.11. Other versions are not supported.

Note

Don't forget --depth 1 when running git clone to avoid large files.

Unit Testing

Running

Setup repo.

Create a test environment.

python -m venv env_dev
source env_dev/bin/activate
pip install -r requirements.txt
pip install -r requirements_test.txt

Run tests

python test.py

You can control which tests to run. Learn more with python test.py --help.

Deprecated

test_old.py is a deprecated, but still accessible test suite focusing on conversion results.

python test_old.py