Speech-to-Text (STT) technology has been widely applied in areas such as meeting transcription, video subtitles, note-taking, and customer service bots. With the proliferation of AI technology, more and more free and effective STT tools have emerged. In this article, we will compare five popular free AI speech-to-text tools: Whisper, Vosk, AssemblyAI (free tier), macOS built-in Dictation, and Speechnotes.
Features:
- Open-source and free, supports multi-language recognition, with especially high accuracy for English.
- Can handle noisy recordings and different accents, offering strong robustness.
- Provides various model sizes (tiny, small, medium, large) to suit different hardware.
- Can run locally, ensuring privacy without needing an internet connection.
Ideal For: Developers, advanced users, and individuals or businesses that prioritize privacy.
Features:
- A lightweight offline speech recognition library, suitable for embedding into mobile devices and IoT devices.
- Supports 20+ languages with minimal resource usage.
- Does not require a powerful GPU; can run on ordinary computers or Raspberry Pi.
- Open-source and free, ideal for customized development.
Ideal For: Developers and technical teams needing local recognition and deployment on small devices.
Features:
- Cloud-based AI transcription service with a monthly free tier (typically around 5 hours of audio).
- Supports automatic interruption detection (paragraph segmentation), keyword extraction, sentiment analysis, and other rich features.
- Fast recognition speed, with particularly good transcription accuracy for English.
- Simple API, ideal for quick integration.
Ideal For: Developers who need short-term project testing or small-scale use of cloud services.
Features:
- Built into the macOS system, completely free to use.
- The local dictation feature (with enhanced dictation enabled) can be used offline, ensuring strong privacy and security.
- Fast recognition speed, ideal for real-time meeting notes and writing input.
- Good compatibility, seamlessly integrates with macOS system apps (such as Notes, Mail, etc.).
Ideal For: Mac users with lightweight speech input needs.
Features:
- Browser-based, ready to use immediately without registration.
- The free version supports unlimited transcription, ideal for quick note-taking and meeting minutes.
- Supports automatic punctuation recognition and basic voice commands.
- Has an Android app for seamless mobile experience.
Ideal For: Casual users, students, and light office workers who need quick access and zero learning curve.
Summary and comparison
| Tool | Advantages | Ideal For |
|---|---|---|
| Whisper | Strong multi-language support, noise resistance, local privacy protection | Developers, privacy-conscious users |
| Vosk | Ultra-lightweight offline operation, low resource requirements | IoT devices, embedded development |
| AssemblyAI | Rich features + API integration, free tier for short-term use | Small project testing, cloud application developers |
| Mac Built-in dictation | Native seamless integration, offline dictation, super simple | Mac users, light office workers |
| Speechnotes | Browser-based, no registration, easy to use | Students, general note-taking users |
