Add subtitles to any video or movie online. Be it on Netflix, Disney+, Youtube or any other online streaming platform.
- By:
- Gaëtan Covelli
- Daily users:
- 10,477 217
- Rating:
- 4.28 (134)
- Version:
- 2.8.1 Last updated: 2025-05-09
- Version code:
- 5941736
- Creation date:
- 2016-02-10
- Risk:
- Moderate risk impact Moderate risk likelihood
- Permissions:
- activeTab
- storage
- scripting
- activeTab
- Host permissions:
- <all_urls>
- <all_urls>
- Size:
- 1.53MB
- Email:
- su*****@substital.com
- URLs:
- Website ,Privacy policy
- Full description:
- See detailed description
- Source:
- Firefox Browser Add-ons
- Data ingested on:
- 2025-07-13
Ranking
# 755 ▲ 6
Other platforms
User reviews
Pros
- Effectively adds subtitles to videos as intended
- Allows customization of subtitle size, color, background, and delay
- Works well for foreign language learners
- Easy to use and setup
- Supports adding subtitles to videos without original subtitles
Cons
- Subtitle synchronization can be inaccurate or off by several seconds
- Does not support displaying subtitles in picture-in-picture mode
- Progress bar may not advance properly during playback
- Cannot display multiple subtitles simultaneously
Recent reviews
After years using it, I must say it does get the job done.
by Na*****, 2025-06-18
by AY*****, 2025-06-14
extension qui ne sert à rien , à rien du tout , hormis vous enlever les sous titres d'origine , et vous proposer de les remplacer par d'autres que vous n'avez évidemment pas !!!!!!!!!!!
by lo*****, 2025-06-05
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.
Substital requires a few sensitive permissions. Exercise caution before installing.
Risk impact analysis details
- Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
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.
Substital is probably trust-worthy. Prefer other publishers if available. Exercise caution when installing this add-on.
Risk likelihood analysis details
- Medium This extension was updated in the past 3 months. New updates may not be stable or safe.
- Medium **** ********* *** ****** **** ****** ********* ********** *** *** ** ****** ** *****
- Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
- Good **** ********* *** **** **** *******
Upgrade to see full risk analysis details
Compare add-ons
- Compare Substital vs Open Subtitles
- Compare Substital vs Subs Translate
- Compare Substital vs Subflix
Similar add-ons
Here are some Firefox add-ons that are similar to Substital:

Open Subtitles
stefan.breitenstein

Subs Translate
cle0

Subflix
hyvyys

SearchSubtitle
Raunak Adak

Search in subtitles on YouTube
Jakub Fidler

Subtitle Scooper
wamason20

Auto-Subtitle Translator
VN88

Multi Subsitles Youtube
GarryW

Stream - Subtitle Downloader
Gilber
Popular extensions / apps
Here are some popular extensions / apps that you might be interested in:
1945 Air Force: Airplane Games
1SOFT
Google Messages
Google LLC
BlockSite Block Websites & Stay Focused
https://blocksite.co/
Ubersuggest - SEO and Keyword Discovery
Ubersuggest
Adobe Acrobat: PDF edit, convert, sign tools
https://www.adobe.com/
Speechify — Text to Speech
https://speechify.com
Tactiq: AI note taker for Google Meet, Zoom and MS Teams
https://tactiq.io
MEGA
https://mega.nz/
Email Tracker by Mailtrack®
https://mailsuite.com
Cursor Helper - Custom Cursors
https://cursor-helper.com
ChatGPT
OpenAI
Coupert - Automatic Coupon Finder & Cashback
https://www.coupert.com/