Caption.IM

Caption.IM is a privacy-first AI captioning assistant built exclusively for macOS. It transforms any audio from your Mac into real-time captions, instant translations, recordings, and structured meeting notes. Unlike browser extensions or meeting bots that require integration with specific apps, Caption.IM captures system audio directly, making it compatible with virtually any application on your computer. This includes Zoom, Google Meet, Microsoft Teams, YouTube, online courses, podcasts, livestreams, webinars, and recorded videos. The product is designed for remote workers, online learners, multilingual teams, content creators, researchers, students, and anyone who needs accessibility features or improved information retention. The core value proposition is simple: turn any conversation into searchable, translatable knowledge instantly. Caption.IM runs locally on your device using local AI and Local LLMs, ensuring your conversations remain private and never leave your Mac. It is optimized for Apple Silicon (M1, M2, M3, and later) to deliver ultra-fast speech recognition with minimal latency and efficient power usage. The setup is straightforward with no complicated configuration required. You simply open the app and start using it immediately. The elegant floating subtitle window works seamlessly with macOS, providing a transparent overlay that does not interfere with your workflow.

Real-Time Transcription

Generate live captions for meetings, videos, podcasts, and calls. The speech recognition engine processes audio in real time, displaying accurate subtitles as words are spoken. This feature works with any application that produces audio on your Mac, including video conferencing tools, media players, and web browsers. The transcription is processed locally on your device, ensuring low latency and complete privacy.

Instant Translation

Understand content in multiple languages with real-time translated subtitles. Caption.IM can detect the source language and provide instant translations into your preferred language. This is particularly useful for multilingual meetings, international webinars, or foreign language content. The translation engine runs locally, so there is no need for an internet connection to access this feature.

Floating Subtitle Window

An elegant transparent overlay that works seamlessly with macOS. This floating window can be positioned anywhere on your screen and resized to your preference. It stays on top of other applications, ensuring you never miss a word. The design is minimal and unobtrusive, allowing you to focus on your content while still having access to live captions.

AI Meeting Summaries

Automatically generate structured summaries and key insights after conversations. Once a meeting or discussion ends, Caption.IM processes the transcription to extract key points, action items, and main takeaways. You can also generate mind maps to visualize the discussion structure. This feature transforms long conversations into concise, actionable information that you can review later.

Remote Meetings and Video Conferencing

For remote workers who participate in multiple video calls daily, Caption.IM provides real-time captions that help with note-taking and information retention. You can capture every word spoken in Zoom, Google Meet, or Microsoft Teams meetings without needing to take manual notes. After the meeting, the AI generates structured summaries with action items, ensuring you never miss important details. This is especially valuable for team members who need to review discussions later or for non-native speakers who benefit from reading captions alongside audio.

Online Learning and Education

Students and researchers can use Caption.IM to caption online courses, lectures, and educational videos. The real-time transcription makes it easier to follow complex material, especially in noisy environments or when the speaker has a heavy accent. After a lecture, you can review the transcript and AI-generated summaries to reinforce learning. This feature is also helpful for creating searchable archives of educational content that can be referenced later.

Multilingual Team Collaboration

For teams working across different languages, Caption.IM provides instant translation of conversations. During international meetings, participants can read translated subtitles in their preferred language, reducing misunderstandings and improving collaboration. This eliminates the need for separate translation services or interpreters, making communication more efficient. The local processing ensures that sensitive business conversations remain private and are not sent to external servers.

Accessibility and Inclusivity

Individuals with hearing impairments or auditory processing difficulties can use Caption.IM to access audio content that would otherwise be inaccessible. The floating subtitle window ensures captions are always visible without interfering with the primary content. This makes video calls, online courses, podcasts, and entertainment content fully accessible. The tool also benefits people in noisy environments or those who prefer reading over listening.

How does Caption.IM capture system audio without browser extensions?

Caption.IM uses macOS system audio capture capabilities to access audio directly from your computer's audio output. This means it can capture audio from any application that produces sound, including video conferencing tools, web browsers, media players, and recording software. There is no need for browser extensions or meeting bots. The app creates a virtual audio device that intercepts system audio, processes it locally, and displays captions in real time.

Is Caption.IM compatible with all Mac models?

Caption.IM is optimized for Apple Silicon Macs (M1, M2, M3, and later) to deliver the best performance with ultra-fast speech recognition and minimal latency. It requires macOS 15.6 or later. While it may work on Intel-based Macs, the performance and accuracy may be reduced. The app is designed to take full advantage of the neural engine in Apple Silicon chips for efficient local processing.

Can I use Caption.IM offline?

Yes, Caption.IM can run entirely offline because all speech recognition and translation processing happens locally on your device. You do not need an internet connection to generate captions, translations, or summaries. This is a key privacy feature that ensures your conversations never leave your Mac. However, some features like cloud-based model updates may require an internet connection.

How does Caption.IM ensure my privacy?

Caption.IM is built with a privacy-first architecture. All audio processing, speech recognition, translation, and summary generation are performed locally on your Mac using local AI models. Your conversations are never sent to external servers or third-party services. No bots join your meetings. No audio data is recorded or stored unless you explicitly choose to save recordings. The app does not collect any personal data, as confirmed by the developer's privacy policy.