YouTube Fullscreen Fit

Name: YouTube Fullscreen Fit
Rating: 4.1935 (31 reviews)
Author: Dinoosauro

Make the YouTube and Invidious player fit all of your screen when opening fullscreen mode. NOTE: After installing, click on the extension and grant the authorization to access YouTube

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Install

Features & Capabilities

YouTube Fullscreen Fit makes every YouTube and Invidious video completely fill your display when entering fullscreen — working with any aspect ratio. Choose automatic activation or keep manual control, and pick between stretching the video to fill the screen or zooming while preserving aspect ratio. Quick toggles appear at the right of the YouTube player so you can enable or disable the feature per video.

Important: after installing, click the extension and grant authorization to access YouTube so the extension can resize videos. This project is open-source — view the source on GitHub: https://github.com/Dinoosauro/youtube-fullscreen-fit

User Growth & Download Statistics

Add-on Open Source

By:

Daily users:

Rating:

Version:

1.8.2 Last updated: 2025-08-31

Version code:

6024359

Creation date:

2023-12-08

Risk:

Permissions:

storage

Content scripts matches:

*.youtube.com
inv.nadeko.net
yewtu.be
invidious.nerdvpn.de
invidious.f5.si
youtube.googleapis.com
*.youtube-nocookie.com

Size:

38.94KB

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-07-11

Compare stats and ranking:

Ranking

# 2,830 ▼ 21

Other rankings

#12 in grant keyword 11

#31 in author keyword 13

#38 in screen keyword 87 ▼ 1

#39 in screen time keyword 16 ▲ 1

#59 in pull keyword 3 ▲ 1

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For Developers

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Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:

Dinoosauro

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/youtube-fullscreen-fit/

User Reviews

Users broadly praise YouTube Fullscreen Fit for adding a reliable fullscreen/fit-to-fill toggle that improves display on mobile and desktop, supports wide aspect ratios like 21:10, and often activates automatically. It’s appreciated for manual control when desired. However, a few users report it does nothing or breaks playback in rare cases, and the extension lacks a settings UI for a default behavior, requiring per-video activation. Overall, it’s a popular, practical enhancement for cropping and fullscreen on YouTube, with occasional reliability issues and feature requests.

Pros

Adds a full-screen fit/zoom-to-fill toggle in YouTube's player, reducing wasted monitor space.
Works well on mobile/Android and often activates automatically.
Supports wide aspect ratios (e.g., 21:10) and cinematic content by cropping to fill.
Offers a manual/auto enable option for control, allowing per-need use.
Frequently praised as a practical, lifesaving enhancement for YouTube fullscreen.

Cons

Does nothing for some users.
No settings dialog or default behavior control; you must enable per video.
Occasional playback disruption reported after enabling.
Some users want the opposite fit behavior (widen instead of zoom).
Reliability can be inconsistent across devices/versions.

Recent reviews

by *****, 2026-05-27

Great and lovely app! however I find myself getting a bit frustrated with the app defaulting to fit screen mode all the time, even something as simple and going out of full-screen and back in for a second will make it cropped in again and I have to press the button again and. Not sure about ultra-wide monitors but my laptop is 16:10 and the sides being cropped really messes up text-heavy videos. If a feature is added that saves your last click i.e fit-screen-mode=0 will make every video not be cropped in persistently until you click the button again (and goes =1) then every video you watch will now be cropped in, this extension will get 5 stars!

by va*****, 2026-04-27

Now im not wasting any monitor space! It works well, ty!

by Ro*****, 2026-03-22

View all user reviews ›

Is YouTube Fullscreen Fit Safe?

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

YouTube Fullscreen Fit requires some sensitive permissions that could impact your browser and data security. Exercise caution before installing.

Risk impact analysis details

Critical Request access to the following domains: youtube.com, nadeko.net, yewtu.be, nerdvpn.de, f5.si, googleapis.com, youtube-nocookie.com
High ******* ******* **** *** ****** ***** *** ***** ** ******* **** ********* ********* ** * *********** *****

Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

YouTube Fullscreen Fit is probably trust-worthy. Prefer other publishers if available. Exercise caution when installing this add-on.

Risk likelihood analysis details

High This extension has low user count. Unpopular extensions may not be stable or safe.
Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
Good **** ********* *** **** **** *******