No Subtitles? How to Get Bilingual Captions on Any Video or Livestream (Mac & iPhone)

TL;DR

When a video or livestream has no caption track, tools that only translate existing CC have nothing to work with. On Mac and iPhone, use BelliedMonkey’s Live Subtitles (macOS 26 / iOS 26): it listens to system audio, turns speech into captions on your device, and shows original + translation. The browser extension does not run speech recognition in the page for no-track video—it points you to the app. For videos that already have captions, the extension’s dual subtitles work on YouTube, X video, and podcasts.

Why some videos have no subtitles

Livestreams, many online courses, and raw uploads often ship without a caption track. Dual-subtitle extensions that only read a track then have nothing to translate—outside guides on “subtitles for any video” (for example Capisco) make the same distinction.

That gap is what Live Subtitles is for: speech → captions → translation, using what the device is playing, not a CC file on the page.

How speech-to-bilingual subtitles work

  1. Recognize speech from system audio on your Mac or iPhone (on-device recognition; no charge for that step).
  2. Correct and translate through the translation engine.
  3. Show the original and the translation together.

The small free credit from optional sign-in does not cover real-time listen-and-translate.

Get bilingual subtitles with BelliedMonkey Live Subtitles

What you need

Languages (Live Subtitles only — confirmed 1.19.4)

Do not reuse the website’s 13-language list or the Settings global「译成」13-language list (zh-CN / zh-TW). Live Subtitles uses a different registry (langs.config.js).

Some languages may appear disabled if the on-device engine doesn’t support them (Thai stays selectable per product); system speech packs may need downloading; “Auto” is not unlimited world coverage.

Mac setup (observed 2026-10-23)

UI labels below match the Chinese App UI from the capture. English readers: follow the same control order in your language.

  1. Open BelliedMonkey Translator.
  2. On the home screen, start Live Subtitles (实时字幕).
  3. On the setup screen, choose source language (视频语言) and translate to (译成), then tap Start (开始).
  4. If the app shows waiting for system authorization (等待系统授权), tap Allow (允许) in the system prompt.
  5. When listening is active, you should see listening / caption status in the app. Bilingual output in this Mac capture appeared as full-sentence pairs inside the App window (best evidence below). Do not assume a separate floating bilingual bar from the Mac shoot alone.
Mac Live Subtitles setup in BelliedMonkey Translator: source language (视频语言) set to English, translate to (译成) set to 中文, and the Start (开始) button, with a prompt to allow screen and system-audio recording (录屏与系统录音).
Mac Live Subtitles inside the BelliedMonkey Translator window on 整句定稿: finalized bilingual sentence pairs, English above Chinese, while listening. The pairs are in the app window.

iPhone setup (observed 2026-10-23)

Capture: ZHAO的iPhone · international TestFlight 1.19.4 (177).

  1. Open 大肚猴翻译 (or belliedmonkey://listen).
  2. On 实时字幕 setup, set 视频语言 to 自动 and 译成 to 中文, then tap 开始.
  3. Listening status shows ● 字幕中 / ● 正在听.
  4. Mic permission on this device was already authorized — the system dialog did not reappear. First-time users may still see a system prompt.
  5. With English audio playing, leave the App: a Picture-in-Picture bilingual floating window appears over Safari.
  6. Back in the App, 整句定稿 shows finalized bilingual pairs.
iPhone Live Subtitles setup: 视频语言 set to 自动, 译成 set to 中文, and the 开始 button.
iPhone Live Subtitles while listening, with status ● 正在听 and a partial English line about a government shutdown.
iPhone Picture-in-Picture bilingual floating window over Safari: English above the Chinese translation, on a page about a government shutdown.
iPhone Live Subtitles 整句定稿: finalized bilingual pairs, English above Chinese, for a passage about a government shutdown.

Mac vs iPhone: Mac shoot has no independent floating bilingual CGWindow bar (use the in-App 整句定稿 capture above). iPhone does have PiP bilingual float.

Engines and privacy

When the video already has captions

If the page already ships a caption track, you may not need Live Subtitles:

The extension does not turn raw audio into subtitles inside the tab. In current versions (1.19.4), tapping AI transcription / 「AI 转写字幕」 in the extension is to_app—it opens the app. The extension never captures system audio.

Options compared

Video’s own caption track + extension dual subs Browser/OS one-language live caption BelliedMonkey Live Subtitles (app)
Works with no CC track No (needs a track; extension confirmed on YouTube, X video, podcasts only) Yes (single language) Yes (system audio)
Shows original + translation Yes, when a track exists One line, one language Bilingual
Platforms Browser extension on supported sites Per vendor Mac (macOS 26+), iPhone (iOS 26+)
Captures system audio No — extension never does Per vendor Yes (with permission)
Cost Currently free Built in Currently free; small free credit with optional sign-in (credit does not cover real-time listen-and-translate)

Built-in browser or OS live caption (for example Chrome Live Caption) is typically one language at a time. This page does not claim it can run alongside BelliedMonkey, or that either replaces the other.

FAQ

How do I get bilingual subtitles on a video with no CC?

Use Live Subtitles in the BelliedMonkey app on Mac or iPhone (macOS 26 / iOS 26). It uses system audio, so it does not need a caption track on the stream.

Can the Chrome / Safari extension do this from the browser tab?

No in-page speech recognition for no-track video. The extension’s AI transcription control opens the app. Dual subtitles in the extension need an existing track and are confirmed on YouTube, X video, and podcasts.

Does it work on livestreams and online courses?

Yes, via system audio in the app, when screen and system-audio recording permission are granted—and the player is actually playing audio on the device.

What OS do I need?

iOS 26 or macOS 26, plus screen and system-audio recording permission.

Is recognition free?

On-device recognition is free. Correction and translation use the translation engine. The free credit does not cover real-time listen-and-translate.

Is the product free?

Currently free; no account needed. Optional sign-in adds a small free credit.

Where does my audio / text go?

Live Subtitles recognition runs on your device. If you use your own API key, your key is stored on your device and requests go to the provider you choose. The free-credit route is relayed through BelliedMonkey’s server, which doesn’t store content.

Get started

Primary CTA: Get BelliedMonkey on the App Store (Mac and iPhone). Currently free. Original and translation, together.

Get it on the App Store

Secondary (only when a caption track already exists on YouTube / X video / podcasts): browser extension — not the main CTA for no-track video or livestreams.

International build: belliedmonkey.cc. Mainland China App Store edition: belliedmonkey.com.