UltraFit - Ultrawide Video - No paywalled features by BabaGurGur

Fit videos on your ultrawide monitor with ease. Many different modes for you to try, as well as smart fit which takes into consideration the video, the video's black bars and others parameters for the best smart fit.

Why use Ultrafit? The main reason: Completely free and no features behind paywalls.

Other ultrawide extensions may present themselves as free, but useful features like per-site settings are behind paywalls.

Available modes are:
Fit - Browser default. Black bars stay.
Stretch - Stretches the picture to fill the screen. Nothing is cropped, the image is distorted.
Fill - Zooms in until the screen is full. No distortion, top and bottom are cropped.
Best fit - Blend of the two. The balance slider goes from pure stretch (0%) to pure zoom (100%).
Smart fit - Looks for black bars burned into the video (e.g. a 2.39:1 film in a 16:9 frame), removes them, then fills the screen. If what's left is within a few percent of the screen's shape it is stretched, otherwise Best fit fills the rest.
Crop to ratio - You choose the shape of the picture to keep (2.39, 2.35, 1.85…). Works on every video, including protected ones.
Custom - Your own horizontal and vertical zoom.

NOTE: The Smart Fit mode does not work with DRM protected streams like Netflix or F1TV. This is because Smart Fit samples the video to detect black bars and adjusts it as needed. DRM protected streams breaks Smart Fit as they cannot be sampled by extensions. Use other modes instead like Crop To Ratio