Netflix VMAF 3.1.0
VMAF sits between encoding and final output, giving everyday users an objective way to check whether their video quality survived the compression process.
You compressed a video. It's smaller now - but does it actually still look good?
That's the question Netflix VMAF answers. Instead of just eyeballing the result and hoping for the best, VMAF gives you a score out of 100 that tells you exactly how close your compressed video is to the original.
Netflix uses this same tool internally before streaming anything to your TV. Now it's free to download and use on Windows 10/11.
What the Score Actually Means
VMAF works like a quality inspector. You give it two files - the original video and your compressed copy - and it compares them the way a human viewer would, not just as raw data. The result is a number:
- 93 and above - Looks virtually identical to the original. Most people won't notice any difference.
- 80 to 92 - Very good quality. Slight softness or detail loss on close inspection, but perfectly watchable.
- Below 70 - Visible quality loss. The compression went too far.
This is far more useful than just staring at two videos side by side, especially for compressed formats like H.265 where differences can be subtle.
Why Would You Actually Use This?
The most common situation is when you're shrinking a large video file - a home movie, a recording, a downloaded file - and you want to know if the smaller version is still worth keeping. You run VMAF on the compressed copy, see the score, and decide whether to keep it or re-encode with better settings.
If you use HandBrake to convert videos, VMAF is the perfect follow-up check.
Encode a short test clip in HandBrake, run it through VMAF, and see whether your quality setting was good enough before processing your entire library.
The same applies if you use FastFlix or MediaCoder for batch conversions - VMAF tells you whether the output matches what you put in.
The VMAF GUI Makes It Easy
Netflix originally built VMAF as a command-line tool, which can be intimidating. Fortunately, a free graphical interface built on top of it is available from this page.
You don't type any commands - you just load your original file, load your compressed file, and click run. The GUI handles everything and shows you the score.
It's a straightforward two-step process: encode your video with whichever tool you prefer, then drop both files into the VMAF GUI to get your result. If the score is good, you're done. If it's too low, go back and adjust your compression settings.
Works Alongside Your Existing Tools
VMAF doesn't replace your video converter or encoder - it works alongside them. The typical workflow looks like this: you use something like x265 HEVC Encoder or FFmpeg to compress the video, then run VMAF to check the result.
If you're not sure which encoder to use, FFmpeg handles virtually every format and works well as the encoding step before a VMAF check.
For playback testing once you have your score, MPC-BE with LAV Filters gives you clean, accurate video playback on Windows so you can confirm what the score is telling you.
VMAF takes the guesswork out of video compression. Instead of second-guessing whether your video still looks good, you get a number - and numbers don't lie.
