Your voice stays yours.

What happens on your device

• Recording, loudness, pauses and pitch are measured in your browser. That audio does not leave your device for these measurements.
• Your attempt history is kept in this browser tab only. If you switch on “Remember attempts on this device”, the numbers (not the audio or transcript) are kept in your browser's storage until you clear them.
• The student build bench keeps code and notes in your browser only. Download a backup to keep them.

What happens only if you opt in

• Transcription. If you tick the box and press Transcribe, the recording is sent over HTTPS to our server on Cloudflare and processed by a speech-recognition model (Whisper, running on Cloudflare Workers AI). The text comes back to your browser. We do not store the audio or the text.
• Structure check. If you tick the box and press Check structure, the transcript is sent to a language model (running on Cloudflare Workers AI, or Anthropic's Claude where a deployment enables it). The scores and quotes come back to your browser. We do not store the transcript or the result. Providers process the request under their own terms; we do not use your content to train models.
• Each opt-in covers one request. The boxes reset after every send.
• AI steps need a demo code handed out by an adult host. Unlocking sets one cookie, limited to our API, that expires after 12 hours. It contains no personal information.

What we never do

• No accounts, no names, no email addresses collected by the app.
• No advertising, no analytics scripts, no third-party trackers, no request logs of content.
• No rating of confidence, emotion, accent, personality or “speaking ability”; no diagnosis of any kind.
• No selling or sharing of anything you say.

Children

Speech Lab is designed for students. Students under 13 should use it with a parent, guardian or teacher present, and the AI steps are only available through an adult with a demo code. Because the app collects no personal information and stores nothing on our server, there is no account or record to delete — closing the tab or clearing browser storage removes everything.

中文摘要

不需要账号；服务器不保存任何录音、文字稿或结果。声音的测量在浏览器内完成。只有在您勾选同意后，录音才会发送到语音识别模型、文字稿才会发送到语言模型，处理完即丢弃。AI 步骤需要成人主持人提供的邀请码。我们从不评价自信、情绪、口音或"演讲能力"，也不做任何诊断。13 岁以下请在家长或老师陪同下使用。