FastFlix is a simple and friendly GUI for encoding videos.

Download latest release from Github

FastFlix keeps HDR10 metadata for x265, which will be expanded to AV1 libraries when available.

It needs FFmpeg (version 4.3 or greater) under the hood for the heavy lifting, and can work with a variety of encoders.

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Check out the FastFlix github wiki for help or more details, and please report bugs or ideas in the github issue tracker!


FastFlix supports the following encoders when their required libraries are found in FFmpeg:

All of these are currently supported by BtbN’s Windows FFmpeg builds which is the default FFmpeg downloaded.

Most other builds do not have all these encoders available by default and may require custom compiling FFmpeg for a specific encoder.


View the releases for binaries for Windows, MacOS or Linux

You will need to have ffmpeg and ffprobe executables on your PATH and they must be executable. Version 4.3 or greater is required. The one in your in your package manager system may not support all encoders or options. Check out the FFmpeg download page for static builds for Linux and Mac.

Running from source code

Requires python3.8+

git clone
cd FastFlix
python3 -m venv venv
. venv/bin/activate
pip install -r requirements.txt
python -m fastflix


On any 10-bit or higher video output, FastFlix will copy the input HDR colorspace (bt2020). Which is different than HDR10 or HDR10+.


FastFlix was created to easily extract / copy HDR10 data, but as of sept 2020, only x265 support copying that data through FFmpeg, no AV1 library does.

VP9 has limited support to copy some existing HDR10 metadata, usually from other VP9 files. Will have the line “Mastering Display Metadata, has_primaries:1 has_luminance:1 …” when it works.


FastFlix supports using generated or extracted JSON HDR10+ Metadata with HEVC encodes via x265. However that is highly dependant on a FFmpeg version that has been compiled with x265 that has HDR10+ support. BtbN’s Windows FFmpeg builds have this support as of 10/23/2020 and may require a manual upgrade.


FastFlix (v4.0.2+) passes through HLG color transfer information to everything except webp and GIF.

Dolby Vision

FastFlix does not plan to support Dolby Vision’s proprietary format at this time.


Copyright (C) 2019-2021 Chris Griffith

The code itself is licensed under the MIT which you can read in the LICENSE file.
Read more about the release licensing in the docs folder.

Encoder icons for VP9 and AOM AV1 are from Wikimedia Commons all others are self created.

Various button icons from

Sample videos and thumbnail for preview image provided by Jessica Payne