AI Speech to Text
Free AI-powered speech to text converter. Transcribe audio and video files to text with timestamps. 100% private, browser-based using OpenAI Whisper.
About AI Speech to Text
This AI-powered transcription tool uses OpenAI's Whisper model to convert speech to text with high accuracy. Unlike cloud-based services, all processing happens directly in your browser using WebGPU/WebAssembly - your audio files are never uploaded to any server, ensuring complete privacy.
How does browser-based transcription work?
The tool uses Transformers.js to run OpenAI's Whisper model directly in your browser. When you first transcribe, the AI model is downloaded and cached in your browser. All audio processing and transcription happens locally on your device using your CPU/GPU, without sending any data to external servers.
Which model size should I choose?
There are three model options:
- Tiny (~40MB): Fastest to load and process. Good for clear audio with minimal background noise.
- Base (~75MB): Balanced option with better accuracy than Tiny.
- Small (~250MB): Best accuracy, especially for challenging audio with accents or background noise. Recommended for important transcriptions.
Larger models provide better accuracy but require more download time and processing power.
What languages are supported?
Whisper supports over 99 languages including English, Spanish, French, German, Chinese, Japanese, Korean, Arabic, Hindi, Portuguese, Russian, Vietnamese, and many more. You can either select the language manually for better accuracy, or let the AI auto-detect the language.
What audio and video formats are supported?
All common audio formats are supported: MP3, WAV, M4A, AAC, FLAC, OGG, OPUS, and WebA. Video files are also supported - the audio track is automatically extracted from MP4, WebM, MKV, AVI, MOV, and other video formats.
How accurate is the transcription?
Whisper provides state-of-the-art accuracy for automatic speech recognition. Results are best for:
- Clear recordings with minimal background noise
- Native speakers with standard accents
- Single-speaker audio
Accuracy may vary for:
- Heavy accents or dialects
- Multiple overlapping speakers
- Poor audio quality or heavy background noise
- Technical jargon or uncommon words
Can I get timestamps and subtitles?
Yes! Enable 'Include timestamps' to get timestamped segments perfect for creating subtitles. You can download the transcript as an SRT file ready for video editing. Enable 'Word-level timestamps' for even more precise timing of individual words.
Why is processing slow on my device?
Transcription speed depends on your hardware. Modern devices with WebGPU support (Chrome 113+) will be significantly faster. To improve performance:
- Use Chrome or Edge browser for WebGPU acceleration
- Close other tabs and applications
- Use the Tiny model for faster processing
- Desktop/laptop computers are faster than mobile devices
- Audio files up to 10 minutes work best
Is my audio data private?
Absolutely. Unlike cloud transcription services, your audio never leaves your device. All AI processing happens locally in your browser using WebGPU or WebAssembly. No audio is uploaded, stored, or processed on any server. When you close the page, all data is cleared from memory.
What's the maximum file size and duration?
Maximum file size is 100MB. For optimal performance, we recommend audio files under 10 minutes. Longer files can be processed but may take significantly more time and memory. If you have longer recordings, consider splitting them into smaller segments.