Open Subtitles

Name: Open Subtitles
Rating: 3.7692 (13 reviews)
Author: stefan.breitenstein

Add subtitles to any HTML5 video sites such as Youtube, Netflix, Amazon Prime Video, Disney+, HBO Max and other stream sites.

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Open Subtitles is a powerful Chrome extension designed to enrich your viewing experience across popular HTML5 video streaming platforms like YouTube, Netflix, Amazon Prime Video, Disney+, HBO Max, and many more. It automatically detects video titles and fetches matching subtitles from OpenSubtitles.com, enabling seamless subtitle integration on your favorite streaming sites.

Key features include support for multiple subtitle formats (*.srt, *.vtt, *.ass, *.ssa), drag-and-drop custom subtitle files, subtitle synchronization, and full customization of subtitle appearance including color, background, transparency, and font size. The extension also works on embedded iframes, allows transcription and text copying, and supports quick navigation through timestamps. Simply install and pin the extension, open a video, and enjoy enhanced subtitle functionality with just a click.

Add-on Video Entertainment Productivity

By:

Daily users:

Rating:

Version:

6.3.8 Last updated: 2023-10-02

Version code:

5631238

Creation date:

2022-05-18

Risk:

Permissions:

activeTab
storage
https://*.plus-sub.com/*
https://gqlos.plus-sub.com/*
https://*.opensubtitles.org/**/*
https://*.opensubtitles.com/**/*
webRequest

Size:

642.43KB

URLs:

Website

Full description:

Source:

Firefox Browser Add-ons

Data ingested on:

2025-07-14

Ranking

# 1,888 ▼ 2

Other rankings

#83 in Language Support

#292 in Appearance

#341 in Other extensions ▲ 1

#9 in openvpn keyword 8

#17 in openai chat keyword 26 ▲ 1

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Other platforms

Open Subtitles (v6.3.8)

10,000 3.64

(22)

User reviews

Users praise Open Subtitles for effectively adding subtitles to videos lacking them, especially on ad-free streaming sites like bilibili, offering useful features and ease of use. Common issues include subtitle desynchronization caused by ads interrupting videos, lack of robust subtitle timing offset adjustments, and overlapping text when font sizes are increased. Some sources may not work with the add-on. Overall, it is valued for its core functionality but struggles with timing sync where ads disrupt playback.

Pros

Works well for streaming videos without ads, especially on sites like bilibili.
Allows playing local subtitle files over remote videos, enabling subtitles where none exist.
Simple and effective for movies missing subtitles.
Works perfectly with many useful features.
Helps users watch videos with missing subtitles by combining video and subtitles from different sources.

Cons

Subtitles get out of sync when videos have ads because the add-on does not adjust subtitle timing for ads.
No built-in way to adjust subtitle offset time (only minor adjustment available) to fix sync issues.
When subtitle font size is increased, two-line subtitles may overlap, reducing readability.
Doesn't work on certain sources/websites, possibly due to compatibility issues.

Recent reviews

by Ro*****, 2025-04-05

by 远离*****, 2025-03-29

by 敬念*****, 2025-02-25

View all user reviews ›

Extension safety

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.

Open Subtitles requires a few sensitive permissions. Exercise caution before installing.

Risk impact analysis details

High Allows the extension to observe and analyze traffic in flight for the selected hosts.
Low ******* ****** ** *** ********* ******** ********************

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 Browser Add-ons, 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.

Open Subtitles has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details

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

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