Studying from lectures without uploading them

What runs entirely on your computer

• Saving the lecture. Your browser fetches the video from the course site, as it does when you watch. It goes to your own folders. Free.
• A transcript from captions. The lecture's own captions are saved as text. Free.
• Transcription. For a lecture with no captions, speech-to-text runs on your machine. The sound is not uploaded, and no minutes are counted. Pro.
• The reading edition. The lecture as a document, made from the transcript by rule: its headings, its contents list and its marks for what the lecturer stressed included. Pro.
• The study page. Slides matched to the transcript by comparing words. Pro.
• Reviewing flashcards. Your cards and your progress are kept in the browser on your computer. Pro.

None of these uses an AI account, and StreamSnag has no account of its own to sign in to. We run no servers that could receive a lecture.

The one step that sends text

A study pack (the study guide, quiz and flashcards) is written by an AI service, and so is the optional tidying of a reading edition. When you start one, that lecture's transcript and the text on its slides, with the speaker notes of a PowerPoint file, go from your computer straight to the AI provider you chose, under your own account. Pictures of slides and the video are never sent. Before each run you are shown what will go and where. If you never choose an AI provider, nothing is ever sent.

How to keep a lecture entirely offline

1. Save the lecture

   Download it from the lecture page. From here on the internet is not needed.

2. Transcribe it on this computer

   Use the captions if there are some. Otherwise press Transcribe on this computer. Setting it up is a one-time download of the speech-to-text program and a model, about 135 MB, which you start yourself in Settings. That is a download to you, not an upload.

3. Read the lecture without AI

   With no AI account chosen, Read the lecture makes the document by rule, at once. If you have chosen one, set “Reading edition: tidy with AI” to Off in Settings, or answer “Make it without AI” when it asks.

4. Make the study page

   Save the slide deck from Files on this page, then press Make study page on the lecture's path. The matching is done locally.

5. Leave the AI provider unset

   AI features are off until you turn them on in Settings. With no provider chosen, nothing can be sent: not a study pack, and not the smaller helpers in the popup (Ask your AI to find it, Summarize, Ask AI why), which in any case show what they would send before they send it.

How to check this for yourself

• The free downloader is open source under the GPL, version 3, so its code can be read.
• The Pro code ships inside the extension, and the licence lets you read it to check what it does.
• Your browser's developer tools show the requests an extension makes. Transcribe a lecture with them open and see for yourself.

Honest limits

• The course site still sees you. Saving a lecture is a download from that site, under your own login.
• A Pro key is checked online. The check carries the key, not your lectures.
• Local speech-to-text is good, not perfect. Speech models of this size misspell unusual drug and technical names. Check a term against the slides before you rely on it.
• Private does not mean permitted. Whether you may keep a recording is up to your course's rules, not to where the file is stored.

Questions