Shadowing Player
Chrome Web Store: coming soon

A Chrome extension for language learners

Turn YouTube into an interactive language practice player.

Practice directly while you watch, one sentence at a time.

  • Shadowing
  • Recall
  • Random sentences
  • Interactive quizzes
Chrome Web Store: coming soonSee how it works

For learners of English and Korean. Works with your own subtitles or a Shadowing Player lesson.

Illustration of the Shadowing Player interface

Don't just watch. Practice every sentence.

Watching is input. Shadowing Player adds the part that makes it stick: you stop on a sentence, say it, and hear it again, without leaving the video.

Just watching
With Shadowing Player

  • Your subtitle, in two languages

    Load a bilingual subtitle and see each sentence in English and Korean, in the panel and on the video.

  • One sentence at a time

    Repeat a sentence once, three times, five times, or until you stop it.

  • Your turn, built in

    The video pauses and waits for you, for a time that follows the length of the sentence.

Four ways to practice

Pick one. The video does the rest.

Listen, then say it

Shadowing

  1. Replay one sentence
  2. Listen
  3. Speak
  4. Repeat

The video stops at the end of each sentence and gives you time to say it before it plays again.

Say it before you hear it

Recall

  1. See or hear the prompt
  2. Think
  3. Speak
  4. Hear the real answer

You get the sentence in the language you know. After a countdown, the video itself gives the answer.

A shuffled session

Random practice

  1. 100 sentences
  2. Shuffled
  3. Each one once
  4. Then a new shuffle

Turn a lesson into a drill. No sentence comes up twice until every sentence has come up once.

Answer on the video

Interactive quiz

  1. Video pauses
  2. Question appears
  3. Choose an answer
  4. Video jumps to feedback

Multiple-choice questions on the video itself, with a different explanation for each answer.

Interactive quiz

Make YouTube lessons interactive.

The video asks a question and pauses. The question and its choices appear right on the video. Pick one, and the video jumps to the part that explains the answer you chose, right or wrong.

  1. Video paused
  2. Question on the video
  3. A / B / C / D
  4. Video branches to feedback
  • A separate explanation for every choice, not one generic "wrong".
  • Mouse or keyboard. The rest of the player keeps working.
  • A score for the session, kept only in your browser tab.

Quizzes come from lesson data. A quiz appears when the video has a Shadowing Player lesson that contains questions; ordinary videos do not turn into quizzes by themselves.

Illustration of the Shadowing Player interface

One player. Two learning directions.

Choose what you are learning. Prompts and answers follow.

Learn English

Korean prompt

체크인하고 싶습니다.

English response

I'd like to check in.

For Korean speakers. Read or hear the Korean, say it in English, then hear how the video says it.

Learn Korean

English prompt

One hot americano, please.

Korean response

따뜻한 아메리카노 한 잔 주세요.

For English speakers. Read or hear the English, say it in Korean, then hear how the video says it.

The language of the interface and the language you are learning are separate settings. The panel is available in English and Korean either way.

How it works

  1. Open a video on YouTube

    Shadowing Player adds a small panel next to regular YouTube videos.

  2. Load subtitles or a lesson

    Use your own bilingual subtitle file, or a Shadowing Player lesson made for that video.

  3. Choose how to practice

    Shadowing, Recall or Quiz; in order or shuffled; then press Play.

What you can load

SRT, VTT
Subtitle files with an English line and a Korean line per sentence.
JSON
The same sentences as data.
Shadowing Player lesson
Sentences plus quizzes, units and the language the video speaks.

Files are read in your browser. Shadowing Player does not fetch or copy the captions of the video.

Everything else you need to practice

  • Sentence repeat1, 3, 5 times or until you stop.
  • Adaptive speaking timeLonger sentences give you longer to speak.
  • Playback speedFrom 0.5× to 1.5×.
  • Subtitle positionMove your subtitle up or down on the video.
  • Show English, Korean or bothHide the language you are testing yourself on.
  • Linear or Random orderIn video order, or shuffled without repeats.
  • Stop or Auto nextStay on a sentence, or keep going.
  • Favorites and masteryMark sentences, and skip the ones you know.
  • Target scopePractice one unit of a lesson at a time.
  • On the videoSubtitle and quiz are drawn inside the player.

For creators

Create videos that become interactive lessons.

If you make language videos, you can publish a lesson file to go with them. Your viewers load it and your video becomes something they can practice with, not only watch.

Guides for teachers: how to film and build a lesson

Lesson format documentation: coming soon

A lesson file can describe

  • sentence timing
  • translations used as recall prompts
  • units for focused practice
  • multiple-choice quizzes
  • a feedback clip for each answer

Private by default

Your lesson data stays in your browser by default.

  • No account

    Nothing to sign up for, and no server that holds your files.

  • Local storage

    Subtitles, settings and your progress are stored in your own browser profile.

  • No video downloads

    Shadowing Player does not download video or audio from YouTube, and does not copy its captions.

  • Honest about voices

    Prompts can be read aloud by the speech built into your browser. How that voice is produced depends on your browser and operating system, and may involve their own services. You can turn it off.

Read the privacy policy

Built for practice, not just viewing

  • WatchingPractice
  • SubtitlesRecall
  • VideoInteractive quiz
  • SentencesRandom drills

Questions

What is Shadowing Player?

A Chrome extension that adds language practice to videos on YouTube. It works sentence by sentence: repeat a sentence, shadow it, recall it from its translation, or answer quiz questions on the video.

Does it work with every YouTube video?

It runs on regular YouTube video pages. To practice you need sentences for that video: your own subtitle file or a Shadowing Player lesson. It does not work on Shorts, embedded players or YouTube Music.

Do I need subtitles?

Yes. You load a subtitle file (SRT, VTT or JSON) or a lesson file. Shadowing Player does not download or read the captions provided on YouTube.

Can I learn English?

Yes. Set the learning target to English: prompts are in Korean and the answers are the English spoken in the video.

Can I learn Korean?

Yes. Set the learning target to Korean: prompts are in English and the answers are the Korean spoken in the video. Use a video that is spoken in Korean.

Does it download YouTube videos?

No. It controls the video player on the page (play, pause, position, speed). It does not download or record video or audio.

Does it work in fullscreen?

The subtitle and the quiz are drawn inside the video player, so they are built to stay with the video in theater mode and fullscreen. Fullscreen is still being verified before launch. The side panel itself is not shown in fullscreen.

What is a Shadowing Player lesson?

A small file a creator makes for a video. It holds the timing and text of each sentence and can add units, quizzes and a feedback clip for each quiz answer.

Is the extension free?

Pricing details will be announced before public launch.

Turn watching into practice.

Add Shadowing Player to Chrome.

Chrome Web Store: coming soon