Youtube Theme Engine

Name: Youtube Theme Engine
Author: BlueCookieWookie

By: BlueCookieWookie Add-on

A fully-local and powerful theme, layout, media, focus, and accessibility engine for YouTube and YouTube Music.

Overview

Firefox Add-ons Store

Daily users

Data as of 2026-08-19

Version:

1.1.2

Last updated: 2026-07-28

Features & Capabilities

Youtube Theme Engine allows you to tweak almost every aspect of the YouTube UI including colors, buttons, text, media, and more.

24 built-in dark, light, and high-contrast themes 18-channel custom palette editor with live color preview Contrast checker for readable text Automatic switching by system theme or a daily schedule Different themes per page (Home, Watch, Shorts, Search, Music, and more) Share and import palettes with theme codes

Layout & Typography

18 fonts plus text size, line height, and weight Content width, video grid columns and spacing, sidebar width Stacked Watch layout with related videos below the player Rounded thumbnails, buttons, and panels, five avatar shapes Custom scrollbar colors and width

Media & Player

Change thumbnail and video brightness, contrast, saturation, grayscale, opacity, etc. Themed progress bar with adjustable thickness Rounded player corners, theater width, cinema glow Hide endscreens, watermarks, info cards, and annotations

Focus (40 toggles)

Zen mode for distraction-free watching Hide Shorts, Playables, comments, related videos, live chat, home feed Hide ads surfaces, merch shelves, and members-only cards Hide view counts, upload dates, likes, badges, and thumbnail overlays Hide completed or live videos, community posts, mixes, and playlists

User Growth & Download Statistics

Add-on

By:

BlueCookieWookie

Daily users:

Version:

1.1.2 Last updated: 2026-07-28

Version code:

6374763

Creation date:

2026-07-25

Risk:

Permissions:

storage

Content scripts matches:

youtube.com
www.youtube.com
m.youtube.com
music.youtube.com
www.youtube-nocookie.com

Size:

448.36KB

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-08-19

Compare stats and ranking:

Ranking

# 127,620 ▲ 2,497

Other rankings

#187 in engine keyword 18 ▲ 1

For Developers

Monetize with App Pass Boost with Extension Booster

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:

BlueCookieWookie

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/youtube-theme-engine/

Is Youtube Theme Engine 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 Theme Engine requires a few sensitive permissions. Exercise caution before installing.

Risk impact analysis details

Critical Request access to the following domains: youtube.com, youtube-nocookie.com
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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 Theme Engine is recently added, and hasn't been around long enough for us to gather enough data to accurately assess its risk level.

Risk likelihood analysis details

High This extension was recently updated in the past month. New updates may not be stable or safe.
High **** ********* *** ******** ****** *** ********** *** *** ** ****** ** *****
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