Captio AI
🦻 Accessibility + 💻 Productivity App

Japanese live captions and productivity tool for tv & media

For deaf and hard of hearing people.

Download for free

Download on theApp Store
Captio AI app showing live captions

Download for free

Download on theApp Store
Use Cases

Every situation covered

Designed for the real moments that matter — not just quiet controlled environments.

📺Live TV — news, sport, events

NHK and commercial broadcasters run live news and sport that pre-generated captions can lag behind. Point Captio AI at your TV and read the Japanese as it is spoken, not several seconds behind the anchor.

🎬Streaming content

TVer, Netflix, and other platforms vary in subtitle quality and availability. Captio AI works as a consistent fallback for any Japanese show or film that ships with wrong, delayed, or missing captions.

📱YouTube and social media

YouTube auto-captions for Japanese are often inaccurate and most social video has none. Point Captio AI at your phone and read accurate Japanese captions for any clip.

🌍Foreign-language content

A foreign film, a foreign documentary, a non-Japanese channel. Live Translator captions and translates in real time so anything becomes watchable in Japanese as it plays.

🎭Cinema

Not every cinema showing is captioned. Hold Captio AI near the audio and read real-time Japanese captions of the dialogue discreetly from your seat.

🎧Podcasts and audio content

Most Japanese podcasts have no transcript. Hold Captio AI near the audio or upload a recording, and read the whole episode in writing.

Performance

Most accurate and fastest models

Japanese
91.3%

character accuracy

independent benchmark, 2025

< 200ms
you speak
captions

real-time captions

first word appears as you speak

Download for free

Download on theApp Store
Captio AI in everyday use
Why Captio AI

Built for the content that subtitles fail

Captions any content in real time

Point the phone toward any speaker — TV, laptop, tablet, cinema screen. Captio AI captions whatever is playing, regardless of whether that platform provides subtitles.

Faster than built-in subtitles for live content

Pre-generated subtitles lag behind live TV by several seconds. Captio AI captions in real time — so you read what is being said as it is being said.

Works on any screen or device

No integration required. Point the phone toward the audio source — the same approach works for a large TV, a laptop screen, a cinema, or a phone held at arm's length.

Any language, translated in real time

For foreign-language content, switch to Live Translator. It translates as content plays — so a French film, a German documentary, or a Japanese series all become watchable.

No subtitle file needed

Captio AI captions from the audio directly. No subtitle file, no platform support, no creator requirement. If audio plays, Captio AI can caption it.

More accurate than auto-generated captions

The industry average for AI-generated subtitles is a 10–15% word error rate — roughly 1 in 10 words wrong (3Play Media). Captio AI is built for accuracy in real-world audio conditions.

Japanese

Why Japanese is hard to understand

Pitch accent

  • Words told apart by pitch, not by the lips
  • Japanese distinguishes many words only by pitch accent — the same sounds mean different things depending on where the pitch falls. Pitch is carried in the voice, not on the mouth, so a deaf viewer watching a drama or a news anchor gets none of the tonal information that fixes the meaning.

Homophone density

  • So many same-sounding words that context decides
  • Japanese has a small sound inventory and vast numbers of homophones, resolved by context and by the kanji in the speaker's mind. In a dense drama or a documentary voiceover, a deaf viewer who misses the context cannot recover which of many identical-sounding words was meant.

Mora timing

  • Length and rhythm that carry meaning
  • Japanese is mora-timed, and vowel and consonant length are contrastive — a long vowel or a doubled consonant makes a different word. These are timing distinctions, not lip shapes, so at broadcast pace they are invisible to a viewer watching a face on screen.

Keigo register

  • Formal honorific speech reshapes whole phrases
  • News and formal programming use keigo — layered honorific forms — that lengthen and restructure verbs and phrases far beyond casual speech. A deaf viewer who lip-reads everyday Japanese meets a formal register on the news in which familiar words take unfamiliar, extended shapes.

Katakana English on screen

  • English terms reshaped into Japanese sounds
  • Variety shows, dramas, and vlogs are full of English loanwords rendered in Japanese sound patterns, plus raw English dropped into Japanese sentences. A deaf viewer must track a term that is neither fully Japanese nor recognisably English, with no lip to read after a fast cut.

Download for free

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The Challenge

Japan captions much of broadcast TV — but not the local and live gaps

Japan has one of the world's oldest populations, and hearing loss rises sharply with age — the number of people with moderate or greater hearing loss is estimated at around 6 million and projected to reach 10 million by 2025. Japan's broadcasting accessibility guidelines require captions on effectively all of NHK's and the major commercial stations' covered programmes, with a target of 80% for regional commercial broadcasters by 2027.

Yet the gaps are real. Over a hundred local TV channels struggle to caption live programmes because of the cost of equipment and staff, so live and regional content is least accessible. Streaming platforms vary and often fail to caption foreign-language content for deaf viewers in Japan, and social and short-video content is largely uncaptioned. Even where captions exist, live programming can lag behind the picture.

Captio AI does not depend on the broadcaster or the platform. Point the phone at any screen — a live NHK bulletin, a regional station, a streaming drama — and read Japanese captions in real time from the audio, whether or not that content was ever captioned.

Download for free

Download on theApp Store
Privacy

What you hear stays with you.

Gone the moment it ends

Captio AI processes your audio in real time and discards it immediately. Nothing is recorded. Nothing is kept.

Not a product

Your conversations are not something Captio AI sells, shares, or monetizes — to anyone, for any reason.

Not used to train anything

What you say in a doctor's appointment or a job interview never ends up in a training dataset. Not ours. Not anyone else's.

100% PRIVATE

Private by default

Download on theApp Store
Reviews

People love Captio AI

"NHK captions a lot, but live news still lags behind the picture and the keigo stretches every sentence. Captio AI captions it in real time from the audio. The words finally line up with the screen."

Haruto S. 🇯🇵
haruto.s***@gmail.com
Hard of hearing, Tokyo — live news viewer

"Local stations here barely caption live shows. Captio AI captions whatever is playing from the audio. I stopped missing the regional programmes just because they were not subtitled."

Yuki T. 🇯🇵
yuki.t***@gmail.com
Deaf, Osaka — regional TV viewer

"Streaming dramas mix katakana English into Japanese constantly and the captions are inconsistent. Captio AI captions all of it from the audio. I follow the whole story now."

Aoi N. 🇯🇵
aoi.n***@gmail.com
Hard of hearing, Kyoto — streaming viewer

"Japanese YouTube auto-captions are unreliable and pitch decides the word anyway. Captio AI captions any clip accurately from the audio. It covers exactly the content the platforms never do."

Ren K. 🇯🇵
ren.k***@gmail.com
Deaf, Yokohama — YouTube viewer

"NHK captions a lot, but live news still lags behind the picture and the keigo stretches every sentence. Captio AI captions it in real time from the audio. The words finally line up with the screen."

Haruto S. 🇯🇵
haruto.s***@gmail.com
Hard of hearing, Tokyo — live news viewer

"Local stations here barely caption live shows. Captio AI captions whatever is playing from the audio. I stopped missing the regional programmes just because they were not subtitled."

Yuki T. 🇯🇵
yuki.t***@gmail.com
Deaf, Osaka — regional TV viewer

"Streaming dramas mix katakana English into Japanese constantly and the captions are inconsistent. Captio AI captions all of it from the audio. I follow the whole story now."

Aoi N. 🇯🇵
aoi.n***@gmail.com
Hard of hearing, Kyoto — streaming viewer

"Japanese YouTube auto-captions are unreliable and pitch decides the word anyway. Captio AI captions any clip accurately from the audio. It covers exactly the content the platforms never do."

Ren K. 🇯🇵
ren.k***@gmail.com
Deaf, Yokohama — YouTube viewer

Download for free

Download on theApp Store
FAQ

Frequently asked questions

Watch anything in Japanese.

Captio AI is free to start

Download for free

Download on theApp Store