What Is the AI Speech-to-Text Tool?
The AI Speech-to-Text tool converts audio recordings into written text using OpenAI's Whisper model running entirely inside your web browser. Powered by WebGPU acceleration, the transcription process happens locally on your device — your audio files are never uploaded to any external server. This makes it ideal for transcribing confidential meetings, interviews, lectures, voice memos, and any audio content where privacy is a priority.
How to Use This Speech-to-Text Tool
- Choose a Whisper model from the dropdown. Smaller models are faster to load and transcribe but less accurate, while larger models produce higher-quality results at the cost of longer processing times.
- Select the language of your audio, or leave it on "Auto Detect" to let the model identify the language automatically.
- Click "Load AI Model" to download the model weights to your browser. This only needs to happen once — the model is cached locally for future visits.
- Once the model is loaded, drag and drop an audio file onto the upload area, or click it to browse your files.
- Optionally enable the "Include timestamps" checkbox to get time-stamped segments in your transcription output.
- Click "Transcribe" and wait for the result. Longer files may take a few moments depending on your hardware.
How It Works
This tool leverages OpenAI's Whisper automatic speech recognition model, compiled to run in the browser through the ONNX Runtime Web framework with WebGPU as the execution backend. WebGPU is a modern browser API that gives web applications direct access to GPU hardware, enabling machine learning inference at near-native speed without any server-side processing. The audio is decoded, resampled to 16 kHz mono, and fed through the Whisper encoder-decoder architecture to produce a text transcript. When timestamps are enabled, the decoder outputs segment-level timing data alongside the transcribed text.
Supported Audio Formats
The tool accepts most common audio formats that your browser can decode. This includes MP3, WAV, FLAC, OGG (Vorbis and Opus), M4A (AAC), and WEBM audio. The maximum file size is 100 MB. For best results with long recordings, files under 25 minutes typically produce the most reliable transcriptions. Longer recordings are split into segments automatically.
Frequently Asked Questions
Is my audio sent to any server?
No. The Whisper model runs entirely in your browser using WebGPU. Your audio file stays on your device throughout the entire transcription process. Nothing is uploaded, streamed, or transmitted to any external service. This approach guarantees complete privacy for sensitive recordings such as medical dictations, legal depositions, or private conversations.
What languages are supported?
Whisper supports over 90 languages including English, Japanese, French, German, Spanish, Chinese, Korean, Arabic, Hindi, Portuguese, Russian, and many more. You can select a specific language from the dropdown for better accuracy, or use the auto-detect feature to let the model identify the spoken language on its own. Multilingual audio files with code-switching may produce mixed results — selecting the primary language manually often improves output quality in such cases.
What is the maximum file size?
The tool supports audio files up to 100 MB in size. For optimal performance, shorter files (under 25 minutes) tend to produce the most accurate transcriptions. Longer recordings are automatically segmented and processed in chunks. If your file exceeds the limit, consider splitting it into smaller segments using a free audio editor before uploading.