Practice with real voices
Use the captioned English videos you already choose to watch.
English shadowing, without the clutter.
Hear the rhythm.
Say it back.
Hear the difference.
Install once, then open any captioned YouTube video and click Deep Shadow. The first-run guide can launch a proven example and the practice panel together in one click.
Free · Desktop Chrome 116+ · No account
One phrase. One clear loop.
A speaking drill that keeps moving.
Deep Shadow handles the timing so you can listen with intent and answer while the speaker’s rhythm is still in your ear.
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01
Listen
Hear one natural phrase in the original speaker’s voice.
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02
Speak
Echo the phrase after the cue. Recording ends on silence.
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03
Compare
Hear the original and your take automatically, back to back.
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04
Repeat
Drill the same phrase again or deliberately move to the next.
Practice by ear
Focus on how English moves.
Control the pace
Work from 0.5× to 1×, then finish at the speaker’s natural speed.
Focus by ear
Hide the picture without losing audio or the practice controls.
Stay in control
Stop a repetition with one click or Escape, or switch to Watch mode anytime.
Private by design
Your voice stays on this device.
Your microphone is used only during your speaking turn. The recording stays in memory, plays once for comparison, and is discarded after the repetition or when practice ends.
- No account
- Audio stays local
- Diagnostics are optional
- No saved recordings
Questions, answered
Before you start shadowing.
Which videos work?
Use a YouTube video with English subtitles or closed captions. Human-authored captions usually produce the cleanest phrase breaks; auto-generated captions can work too.
Why does Deep Shadow need my microphone?
It records your speaking turn so you can immediately compare it with the original phrase. Chrome asks you before access begins.
Does my voice leave the device?
No. Audio is neither uploaded nor sent to the developer.
Are recordings saved?
No. Each take remains in memory for its comparison and is discarded afterward or when the session ends.
Do I need an account?
No. Deep Shadow has no sign-in, subscription, advertising, or cloud sync. Anonymous diagnostics are optional.
What browser do I need?
Desktop Google Chrome version 114 or later on macOS, Windows, or Linux.
Should I use headphones?
They are recommended. Headphones keep the model phrase out of the microphone and make the A/B comparison clearer.
What if captions or the microphone do not work?
Reload the video after installation, start playback once, confirm English captions are available, and review Chrome’s microphone site settings. More help is available on the support page.
Deep Shadow 1.0
Real English. One phrase at a time.
Available free on the Chrome Web Store.
Get Deep Shadow