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Video subtitle translator — tap a word to translate

CIRCØ includes a video player with tap-to-translate subtitles. Play a local video, turn on subtitles, and tap any subtitle word — or select a phrase — to translate it on the fly. It's the easiest way to learn a language from films, shows, and clips. No account, no install, and your video never leaves your device.

How it works

1. Open circ0.com and upload a video file (MP4, MKV, MOV, WEBM, AVI, FLV).
2. Show subtitles — use ones embedded in the file or upload a sidecar SRT/VTT.
3. Set the From and To languages in the header.
4. Tap a subtitle word or select a phrase to translate it instantly while the video plays.

Player features

• Tap-to-translate subtitle overlay for word and phrase lookups.
• Subtitle translate scrubbing — skip directly subtitle-by-subtitle using keyboard arrows or touchscreen double-taps when translating.
• Embedded subtitle extraction plus sidecar SRT/VTT uploads.
• Subtitle timing shift to fix out-of-sync captions.
• Multi-track audio selection and external audio uploads.
• Local playback — your video is never uploaded.

Great for language learning

Watch in your target language and translate only the subtitle words you don't recognize, building vocabulary in context as you watch. Every word you translate is saved to your history, so the time you spend watching also tracks your progress. Only the subtitle text you tap is sent off-device.

What is tap-to-translate for video subtitles?

Tap-to-translate lets you watch a video with foreign-language subtitles and instantly translate individual words or phrases by tapping them. Instead of pausing to look up a dictionary or translating the entire subtitle track at once, you interact with the exact word you don't understand — and the translation appears as an overlay while the video keeps playing.

CIRCØ brings this experience to your browser for free. Open any local video file, enable subtitles (embedded or a sidecar SRT/VTT), and tap to translate. There is nothing to install: it works on desktop and mobile in Chrome, Firefox, Safari, and Edge.

How is CIRCØ different from subtitle translation extensions?

Most subtitle translation tools are browser extensions tied to a single streaming platform. CIRCØ takes a different approach — it is a standalone web app that works with any video file you already have. Here's how it compares:

• No extension or install required — open circ0.com in any modern browser and start immediately. No Chrome Web Store, no desktop download, no account signup.
• Privacy-first architecture — your video file stays on your device and is never uploaded to a server. Only the specific subtitle text you tap is sent off-device for translation.
• Combined reader and video player — CIRCØ is not just a video tool. The same app also lets you read and translate EPUB books, PDFs, and comics, so you can keep all your language-learning content in one place.
• Built-in vocabulary tracking — every word you translate is saved to your vocabulary history. Review what you've learned, track progress over time, and see which words you look up most often.
• Works offline as a PWA — install CIRCØ to your home screen and use it without an internet connection (translations require connectivity, but playback and reading work offline).

Which languages are supported for subtitle translation?

CIRCØ currently supports nine languages for subtitle translation. You can translate between any pair — for example, Japanese subtitles to English, or Spanish subtitles to French:

1. English
2. Spanish
3. French
4. German
5. Italian
6. Portuguese
7. Russian
8. Japanese
9. Chinese

Set the From language (the language the subtitles are in) and the To language (the language you want translations in) using the header bar at the top of CIRCØ.

Can I translate Netflix or YouTube subtitles?

CIRCØ works with local video files — MP4, MKV, MOV, WEBM, AVI, and FLV — rather than streaming services directly. It does not inject into Netflix, YouTube, or other streaming platforms the way a browser extension would.

However, many streaming services let you download videos for offline viewing. Once you have a downloaded file, you can open it in CIRCØ and use tap-to-translate on its subtitles. This approach also works with videos you record yourself, educational content, and any other video file you own.

Is subtitle translation free and private?

Yes — CIRCØ is completely free to use and built with privacy as a core principle. Your video files are never uploaded; they play locally in your browser using the device's own media engine. The only data sent off-device is the specific subtitle text you tap for translation.

There is no account required, no tracking of what you watch, and no ads. You can review the full privacy policy for details. Because CIRCØ is a progressive web app, you can install it to your device and use the player offline — only live translations need an internet connection.

Questions? Email circ0@circ0.com. See our privacy policy and terms of use.