Watchmarker for Youtube

Name: Watchmarker for Youtube
Rating: 4.6419 (148 reviews)
Author: sniklaus

By: sniklaus

Automatically mark videos on Youtube that you have already watched.

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Features & Capabilities

Watchmarker for Youtube is a Chrome extension that enhances your Youtube experience by automatically marking all videos you've previously watched, not just the recent ones. Unlike Youtube’s native feature—which only marks videos viewed recently—this extension maintains a comprehensive watch history, allowing you to easily identify videos you've seen over time.

Key highlights include an export and import feature for backing up your watch history, ensuring data persistence even if you switch devices or clear browser data. You can also manually synchronize your full watch history through the settings to keep everything up-to-date. The extension is free and actively maintained, with support available via its GitHub page for any issues or feature requests.

This tool is perfect for avid Youtube users who want a reliable way to track their viewing habits across sessions.

User Growth & Download Statistics

Add-on

By:

Daily users:

Rating:

Version:

5.1.0 Last updated: 2026-04-10

Version code:

6214975

Creation date:

2015-05-30

Risk:

Permissions:

Host permissions:

*://www.youtube.com/*
*://m.youtube.com/*

Content scripts matches:

www.youtube.com
m.youtube.com

Size:

426.40KB

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-07-12

Compare stats and ranking:

Ranking

# 1,615 ▲ 6

Other rankings

#271 in Photos, Music & Videos ▼ 1

#15 in marker keyword 31

#22 in match keyword 18 ▲ 1

#26 in watch keyword 22

#85 in youtube keyword 85

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Other platforms

Watchmarker for Youtube (v5.1.0)

10,000 4.44

(153)

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:

sniklaus

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/watchmarker-for-youtube/

Permission Change History

2026-04-10: Version 5.0.5 → 5.1.0

Add Permissions: webRequest webRequestBlocking

2025-09-30: Version 5.0.0 → 5.0.1

Remove Permissions: downloads

2025-09-26: Version 4.7.1 → 5.0.0

Add Host permissions: *://www.youtube.com/* *://m.youtube.com/*

Add Permissions: declarativeNetRequest declarativeNetRequestWithHostAccess scripting storage

Remove Permissions: webRequest webRequestBlocking https://www.youtube.com/* https://m.youtube.com/*

2025-01-09: Version 4.6.1 → 4.7.0

Add Permissions: https://m.youtube.com/*

2024-01-02: Version 4.4.2 → 4.5.1

Add Permissions: https://www.youtube.com/*

Remove Permissions: *://www.youtube.com/* *://*.ytimg.com/vi/*/*

User Reviews

Users praise Watchmarker for clearly labeling watched videos and for importing/exporting watched history across browsers, with strong sentiment that it’s a must-have. However, multiple reviews note reliability problems, inconsistent page-wide behavior (main vs subs vs search), and occasional resets of watch history or viewing dates. Some report updates restoring functionality and good compatibility with YouTube Redux, but ongoing reliability remains a common concern.

Pros

Clearly labels watched videos, helping avoid re-watching.
Supports import/export of watched videos across browsers (including import from Firefox history and YouTube).
Very useful / must-have extension for YouTube viewing management.
Works well with YouTube Redux extension to maintain compatibility with older UI.

Cons

Unreliable: stops working frequently across updates and pages.
Inconsistent behavior across YouTube pages (main page, subscriptions, and search) where videos may not be marked as watched.
Watch history and video viewing dates can reset unpredictably.

Recent reviews

This ext has become soo useful over time, indispensable even. Thx Dr. N for updating so it works again! 😄

by Fi*****, 2026-04-12

works again, and is absolutely indispensible.

by Vi*****, 2026-04-09

No longer works

by un*****, 2026-04-08

View all user reviews ›

Is Watchmarker for Youtube 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.

Watchmarker for Youtube requires a lot of sensitive permissions. Exercise caution before installing.

Risk impact analysis details

Critical Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
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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.

Watchmarker for Youtube 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.
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