Caption.IM

Caption.IM is a privacy-first AI captioning assistant designed exclusively for macOS. It solves a common problem for professionals, students, and content consumers: the inability to generate real-time captions, translations, and structured notes from any audio source on your Mac without relying on third-party bots or browser extensions. Unlike typical solutions that only work within specific apps like Zoom or require a bot to join your meeting, Caption.IM captures system audio directly. This means it works universally across almost any application you use, including Zoom, Google Meet, Microsoft Teams, YouTube, online courses, podcasts, livestreams, webinars, and even recorded video files. The core value proposition is turning any conversation or audio stream into searchable, translatable, and actionable knowledge instantly. It provides a floating subtitle window that overlays elegantly on your screen, offering real-time transcription and instant translation of multiple languages. After a meeting or listening session, it can automatically generate structured summaries, key points, action items, and even mind maps. All of this processing is done locally on your device using local AI and Local LLMs, ensuring your conversations remain private and never leave your Mac. Caption.IM is optimized for Apple Silicon (M1, M2, M3, and later) to deliver ultra-fast speech recognition with minimal latency and efficient power usage. It is ideal for remote workers, multilingual teams, online learners, accessibility advocates, content creators, researchers, and students who need to capture and understand spoken information without friction or privacy concerns.

Real-Time Transcription

Caption.IM generates live captions for any audio playing on your Mac. Whether you are in a video call, watching a recorded lecture, or listening to a podcast, the app transcribes speech into text in real time. This feature is powered by local AI on your device, ensuring low latency and high accuracy. The transcription appears in a sleek, transparent floating window that can be positioned anywhere on your screen, making it easy to follow along without disrupting your workflow. You can also record these transcriptions for later review, turning ephemeral conversations into permanent, searchable text documents.

Instant Translation

Break down language barriers instantly with real-time translated subtitles. Caption.IM can translate spoken content from one language into another as it is being spoken. This is particularly useful for multilingual meetings, international webinars, or consuming foreign language content like news broadcasts or online courses. The translations appear alongside or in place of the original captions in the floating window, allowing you to understand and engage with content that would otherwise be inaccessible. All translation processing happens locally, preserving the privacy of your conversations.

Floating Subtitle Window

The user interface is designed for minimal disruption and maximum utility. Caption.IM provides an elegant, transparent overlay that floats on top of your other applications. You can resize, reposition, and customize the opacity of this window to suit your preferences. It seamlessly integrates with macOS, appearing unobtrusively while you work. This design ensures that you can read captions or translations without constantly switching windows or losing focus on the primary content, whether it is a video call, a presentation, or a video player.

AI Meeting Summaries

After a conversation, meeting, or lecture, Caption.IM does more than just provide a transcript. It automatically analyzes the recorded audio and generates structured summaries. These summaries include key points discussed, action items assigned, and a concise overview of the entire session. You can even generate mind maps to visualize the flow of ideas. This feature transforms hours of discussion into digestible, actionable information, saving you significant time on note-taking and review. It is a powerful tool for productivity, ensuring no critical detail is missed.

Remote Meetings and Video Calls

Professionals participating in virtual meetings on Zoom, Google Meet, or Microsoft Teams can use Caption.IM to get real-time captions of everything being said. This is invaluable for participants who are hard of hearing, non-native speakers, or those in noisy environments. The AI meeting summaries ensure that even if you miss a part of the call, you can quickly catch up on key points and action items without replaying the entire recording. It also allows you to focus on the discussion rather than frantic note-taking.

Online Learning and Education

Students taking online courses, watching recorded lectures, or participating in webinars can benefit greatly from Caption.IM. Real-time captions help with comprehension, especially for complex subjects or when the instructor speaks quickly. The ability to translate content in real time is a game-changer for international students. After a lecture, the AI-generated summaries and mind maps provide a powerful study aid, helping to reinforce learning and organize information for exams or projects. It turns passive video watching into an active, productive learning experience.

Multilingual Team Collaboration

For teams that work across different languages, Caption.IM serves as a universal translator. During meetings, participants can read real-time translations of what their colleagues are saying, regardless of the language being spoken. This fosters better understanding, reduces miscommunication, and ensures everyone can contribute equally. The recorded transcripts and summaries become a shared, searchable knowledge base that is accessible to all team members, regardless of their native language, improving overall collaboration and information equity.

Content Creation and Research

Content creators, journalists, and researchers can use Caption.IM to transcribe interviews, podcasts, and livestreams instantly. Instead of spending hours manually transcribing audio, they can generate accurate text in real time. The floating window allows them to monitor the transcription while recording or interviewing. Later, they can search the transcript for specific quotes, generate summaries for show notes, or use the mind maps to structure their articles or videos. This streamlines the entire content production workflow from capture to publication.

Does Caption.IM work with any app on my Mac?

Yes, that is one of its core strengths. Because Caption.IM captures system audio directly at the source, it works with virtually any application that produces sound. This includes video conferencing tools like Zoom, Google Meet, and Microsoft Teams, web browsers for YouTube and online courses, media players for podcasts and videos, and any other app with an audio output. There is no need for browser extensions or for a bot to join your meeting.

How does Caption.IM protect my privacy?

Privacy is a foundational principle of Caption.IM. All speech recognition and processing, including transcription and translation, can run entirely locally on your Mac using local AI and Local LLMs. This means your audio data and conversations never leave your device or are sent to external servers for processing. No bots join your meetings, and no third parties have access to your spoken content. This makes it a secure choice for sensitive business discussions or personal conversations.

Is Caption.IM optimized for my Mac's hardware?

Yes, Caption.IM is specifically designed and optimized for Apple Silicon (M1, M2, M3, and later chips). This optimization ensures ultra-fast speech recognition with minimal latency, allowing captions to appear almost instantly as words are spoken. It also results in efficient power usage, so it does not drain your battery excessively during long meetings or listening sessions. The app requires macOS 15.6 or later.

Can I get summaries and action items from a recorded meeting?

Absolutely. This is a key feature of Caption.IM. After you have recorded a meeting, lecture, or any audio session, the app can automatically process the recording to generate structured outputs. These include a concise summary of the discussion, a list of key points, specific action items, and even a visual mind map of the conversation. This turns lengthy audio recordings into practical, actionable documents that are easy to review and share.