YouTube Video Subtitles with Real-Time Translation

Break the Language Barrier on YouTube 🎬

That tutorial you need is in Korean. That documentary is in Japanese. That interview? French. The content you want to watch doesn't always speak your language.

Until now.

We're thrilled to announce Video Subtitles—a feature that brings real-time subtitle translation directly into your YouTube viewing experience. Watch any video with bilingual subtitles, customize the display to your liking, and never miss a word.

Public Beta: Video subtitles is now available to all users! Enable it in Options → Video Subtitles.

YouTube video with bilingual subtitles

What's Inside This Update

This isn't just subtitle translation—it's a complete viewing experience designed around you:

Feature	What It Does
Bilingual Display	See original and translation side by side
Display Modes	Original only, translation only, or both
Custom Styling	Font, size, color, weight—your choice
Draggable Position	Move subtitles anywhere on screen
Auto-Start	Translations begin when videos load
Smart Batching	Translates ahead, not all at once

Three Display Modes

Choose how you want to see your subtitles:

Bilingual Mode

See both the original text and translation. Perfect for language learning—read the original while understanding through translation.

Original Only

Just the source language. Use this when you understand the language but want cleaner captions than YouTube's auto-generated ones.

Translation Only

Pure translation. When you just want to understand the content without distraction.

Language learners: Use bilingual mode with translation positioned above the original. Your eyes naturally read top-to-bottom, so you'll see the translation first, then connect it to the original text below.

Make It Yours: Full Customization

Subtitles should match your viewing style, not the other way around.

Text Styling

Customize separately for main subtitles and translations:

Font Family: System fonts or custom choices
Font Size: Scale from tiny to large
Font Color: Any color you prefer
Font Weight: Light to bold

Container Settings

Background Opacity: From transparent to solid
Translation Position: Above or below the original text

Subtitle style settings panel

Every settings card has a Reset button. Experimented too much? One click returns to defaults.

Drag to Position

Subtitles blocking important content? Just drag them.

Hover over the subtitle area to reveal the drag handle, then move the subtitles anywhere vertically on the video. The position:

Persists during playback
Works in fullscreen mode
Stays within video bounds

Smart Translation: Batch Processing

We don't translate all subtitles upfront—that would waste API tokens on videos you might not finish.

Instead, Read Frog uses intelligent batch pre-translation:

When	What Happens
Video starts	First 50 seconds translated
Within 40s of next batch	Next 60s batch begins
User seeks ahead	Relevant batch translates immediately
Background	Silent translation, no loading states

Token efficient: Only translates what you'll actually watch. Skip to the end? Those earlier batches stay untranslated.

Auto-Start Translation

Don't want to click the translate button every time?

Enable Auto-Start in settings, and subtitles automatically begin translating when you open a YouTube video. The translation runs silently in the background—you'll only see a "Processing" state if you jump to an untranslated section.

Auto-start settings toggle

Better ASR Subtitle Segmentation

YouTube's auto-generated subtitles (ASR) often have awkward breaks:

Before:

"I think that"
"this is really"
"important because"

After:

"I think that this is really important because..."

We improved the segmentation algorithm to:

Accumulate text across events until natural sentence boundaries
Handle CJK languages with character-based limits
Add proper spacing for English when merging
Support international punctuation (Chinese、Arabic، Hindi।)

International Support

Subtitles work across languages—not just English to your language, but any source to any target.

We've added support for sentence-ending punctuation in:

Chinese: 。？！；
Arabic: ؟
Urdu: ۔
Hindi: । ॥
And more...

This means cleaner subtitle breaks regardless of the video's original language.

How to Get Started

1. Enable Video Subtitles

Go to Options → Video Subtitles and flip the toggle.

2. (Optional) Enable Auto-Start

Turn on auto-start if you want translations to begin automatically.

3. (Optional) Customize Your Style

Adjust display mode, fonts, colors, and positioning to your preference.

4. Watch a Video

Navigate to any YouTube video. Click the Read Frog button in the player controls (or let auto-start handle it).

Supported Platforms

Currently supported:

✅ YouTube (all videos with available subtitles)

Coming soon:

🔜 Additional video platforms

Note: Video subtitles require the video to have subtitles available (either uploaded or auto-generated by YouTube).

Technical Highlights

For those curious about how it works:

XHR Interception: Captures subtitle data directly from YouTube's API
Multiple Formats: Supports standard, karaoke, and scrolling ASR captions
Separate Queue: Video translations use their own processing queue, separate from article translations
Shadow DOM: Subtitles render in isolation, preventing style conflicts

What's Next?

This is the public beta—we're just getting started:

🎨 More styling options (outlines, shadows)
🌐 Additional video platforms
📝 Subtitle export functionality
🔊 Combined with TTS for audio translation

Try It Now

Update to the latest version of Read Frog and experience YouTube in any language.

Found a bug? Have a suggestion? Share your feedback on GitHub Issues—your input shapes what we build next.

Happy watching! 🎬