Hello folks. I hope you are gonna have a fantastic weekend aheard, as I am bringing you a big update for Captionz! I’m launching Captionz‑ext, an ultra-lightweight browser extension that finally makes dual subtitles on YouTube practical. Thanks to auto‑translate, you can pair almost any language, do quick A‑B repeats, and add community notes, all while you watch.

As you know, dual subtitles have always been my goal. Finally they’re realistic for most videos, which means our second subtitle can finally show up 🙂
And the best part: Captionz is completely free. I first thought I’d need AI to translate captions (which would cost money), but YouTube already provides auto‑translate. I just enhance the experience and bring both subtitles together.

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Why This Is a Milestone

My goal is to help you learn from real videos, like movies, interviews, lectures, and news etc. without losing your flow. I built [Captionz‑ext] to make dual subtitles practical on most YouTube videos by adding auto‑translate when only one track exists. It also syncs with the Captionz web app for tools like A‑B repeat, notes, and search. Simple setup, more learning.

Free — No AI Fees

Early on, I planned to use AI to translate captions, which would have meant a paid “pro” plan. Thankfully, YouTube already has auto‑translate. Captionz‑ext simply connects the dots so you can see two subtitles at once. Enjoy Captionz completely free.

What’s New Auto‑translate: Turn it on to cover almost any language. If a video has only one caption track, auto‑translate adds the second. Dual subtitles: My core goal, now practical on most videos. See two languages at once. One‑click access: I added a “Watch on Captionz” button on YouTube video pages. Context menu: I added a right‑click menu to open any YouTube link in Captionz. Sync with Captionz: Captions flow into Captionz, so A‑B repeat, notes, and Dictionariez work right away.

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How It Works

I built Captionz‑ext to read the captions (and auto‑translated ones) on YouTube, then sync them with the Captionz web app. Many videos only include one auto‑generated track, auto‑translate provides the second. Pick your two languages and watch them side by side. No complicated setup, no secret switches.

A Brief History

Five years ago, I launched the first version of Captionz. My debut post on Reddit was a hit: “I made a site that helps you watch YouTube with dual subtitles”.

Back then, I didn’t need an extension. YouTube captions were public; you could request and download tracks, and Captionz could combine languages freely.

Later, YouTube restricted external caption requests. To keep things working, I added a handy button in Dictionariez so users could still open videos on Captionz with dual subtitles — at least for videos that had multiple tracks by default.

A few months ago, YouTube encrypted caption requests, which made access harder. I switched to a simple, privacy‑friendly approach with a lightweight extension and separated Captionz from Dictionariez. That keeps Dictionariez focused and gives Captionz users a stronger, dedicated tool.

And yes: I made Captionz‑ext free and open‑source. High‑fives all around.

Who It’s For Learners: Compare native + target language subtitles in real time to build comprehension and confidence. Teachers & Tutors: Use any YouTube video for bilingual instruction with A‑B looping and notes. Polyglots: Switch language pairs and auto‑translate to explore content across the world. Casual Viewers: Understand more, faster—without pausing to look things up. Quick Start Chrome: Install from the Chrome Web Store. Edge: Install from Microsoft Edge Add‑ons. Firefox: Pending review. Stay tuned on the Add‑ons listing.

Open any YouTube video and click “Watch on Captionz.” Or right‑click a video link and choose “Open in Captionz.” Pick your two languages, turn on auto‑translate if needed, and you’re set. Your coffee can stay hot; setup is quick.

Manual Installation (Alternative) Download the source code from GitHub. Go to chrome://extensions/ in your browser. Enable Developer mode (top right). Click Load unpacked and select the extension folder. Privacy

I aim for minimal, respectful integration. Captionz‑ext only accesses captions needed to enable features and does not collect personal browsing history. Read the privacy policy for details and updates.

FAQs Do dual subtitles work on all videos? It depends on captions. Many videos have only one auto‑generated track; turn on auto‑translate to add the second language. Which languages are supported? Auto‑translate covers most languages YouTube supports. Dual subtitles work when two tracks exist or one is auto‑translated. Do I need the Captionz web app? The extension helps on YouTube and pairs with Captionz for A‑B repeat, notes, and more. Together is best. Does this work on Shorts? Not at the moment. Do you really want it to work on Shorts? Comment below to let me know. Is it free? Yes — and there are no AI translation fees. Auto‑translate is provided by YouTube; Captionz just enhances the experience. Call to Action

Install Captionz‑ext (it’s free) and try dual subtitles on your next video:

Chrome: Captionz – YouTube Dual Subtitles Edge: Captionz – YouTube Dual Subtitles Firefox: Coming soon—pending review

Open a video you love, turn on auto‑translate to widen language coverage, and use A‑B repeat to nail tricky lines. Add a note or two to help the next learner (or future you).

TL;DR

Captionz + Captionz‑ext = dual subtitles on YouTube—made practical by auto‑translate—plus A‑B repeat and notes, across almost all languages. It’s completely free. Click “Watch on Captionz” and start learning faster. Smiles optional, progress guaranteed.

Hi everyone. Happy new year! Welcome to Captionz Trove, a space dedicated to new & educational YouTube videos. Why? Because it's fun.

But first, have you read this topic: Welcome to pnlpal? This is the one that introduce to you the reason why I built this site, the intention of making it and the rules of posting. I suggest you read it first.

What is Captionz?

It’s a website, part of our pnlpal community that let you watch YouTube videos with dual captions, A-B repeat and more. just open Captionz to use it. No need to use a browser extension, or an app. It’s simple and straight-forward, right?

I actually launched it at LanguageLearning subreddit first, it's fairly good.
screenshot of reddit

Later, I put it on InternetIsBeautiful, it soared.
screenshot of reddit

But then comes the down turn. People loved it and forget it.
screenshot

Anyway, I put the detail story here:
Captionz: learn on YouTube with fun.

Since you are here reading this post, you actually like it. I appreciate that.

Let's continue.

What's Captionz Trove?

Well, it's just a category on pnlpal. After published Captionz, I built this to help us share and discover educational videos on YouTube. It's bit of hard to dig resources on YouTube these days. YouTube is more and more entertaining rather than educational I think. So by creating this place, I hope it could help you reduce some noise, and discover educational videos more easily, and learn languages more efficient.

The core function of this trove is that first, it has a Reddit like ranking algorithm to sort the topics. So it relies on real human upvotes and suggestions. What is the reddit ranking algorithm like? There is a good article writing about this:

How Reddit ranking algorithms work.
(Though I have to confess that I am still working on it. It needs a lot of posts to see the real effect. There are not many posts now anyway. But you should see it soon.)

Second, a Twitter like UI, so it looks clean. I love twitter so much that you can see me there every day. Let's connected there, shall we?

It's meaningful, isn't it? I watched most of the videos in the trove. Hell, I think I am addicted to YouTube. When I find a video that is interesting and thoughtful, I share it. I have really learned a lot from these videos. For example:

How to learn any language in six months | Chris Lonsdale | TEDxLingnanUniversity The Myth of Education & Impact: Inner Architecture Mini Lockdown math

That's why I built this place. I urge you to do the same with me. Share the video that you watched and learned. So you are not just helping me, but also helping every language learners out here, and even the youtubers! You are spreading works and ideas worth spreading.

How?

Simple, click the New Topic button. Put the title and url of the video in, and write a few words for introduction.

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Don't forget to use or create a few tags. They are meaningful to classify these posts.

Again, before you post, a few simple rules you should know.

Rules General rules I mentioned here, you know no bullshit, no propaganda, looking for original etc. New & educational videos only. I don't want this space full of entertainment. Though you might think that entertainment is also educational, you can learn languages from videos like games or sports. But that's just another YouTube.com. But I do think talk shows or something like learning English from Friends are proper here. Debates are welcome. If it's too old, it's old-fashioned. I don't like it. But there are just some things that never grow old and never die. You'll hate that you didn't find them earlier, and they might have changed your life. Justice: What's The Right Thing To Do? How to learn any language in six months | Chris Lonsdale | TEDxLingnanUniversity It's important to have at least one caption. Auto-generated caption is not recommended. You know why. More videos and channels

Please, help me grow this space, add more videos, discover more channels.
I bet you love YouTube, and you have subscribed a lot of channels, right? Or better, you have created your own channel? Leave a comment below, tell me your favorite educational channels. I'll consider to put it in the sidebar of this site. Yours is better.

This is the way.