Silestis: Find the moment in your video
Silestis turns supported lectures, webinars and portal videos into searchable transcripts and answers, starting right in Safari. The extension comes with the Mac app. Timestamps are available with supported modes.
Mac app + Safari extension · Free to start
[02:14]Today we'll cover gradient descent and why the learning rate matters more than you think.
[08:41]The key insight is that a learning rate too high causes divergence, while too low gets stuck in local minima.
[16:33]Let me show you Adam optimizer — it adapts the learning rate per parameter, which is why it works so well in practice.
[22:47]Now, backpropagation through the network...
* Typical benchmark for On-device and supported on-demand sources using the fast path. Actual time varies by source, selected mode, file format, device, and service load.
From the page you're on to answers
Three steps, right where you're watching.
Open the video you already have access to
A gated lecture portal, a webinar, a SharePoint or Drive video, a podcast — the extension detects the stream on the page, even with no transcript.
One click, right on the page
For supported pages, the extension starts the workflow without manually downloading or copying captions. Processing continues in the background.
Get answers — and a searchable memory
Ask questions and get timestamp references when the selected mode supports them. Generate summaries, notes, and flashcards, then search across your library.
Turn hard-to-reach video into answers
From gated lectures and transcript-less webinars to your podcast backlog — then a searchable memory you can ask
No transcript? Transcribe the supported source
When there's no caption to lean on, Silestis transcribes the audio on the page with 3 focused AI modes for lectures, meetings, interviews, and podcasts — so gated and transcript-less video still becomes answers, fast.
Ask questions, get answers
"What were the key takeaways?" — AI answers with clickable [mm:ss] timestamps when the selected transcription mode provides them.
Structure from supported recordings
AI generates structured notes, chapter marks, and key-point flashcards — from meetings, interviews, or lectures.
A searchable memory of what you capture
"What did the professor say about the exam?" — Semantic Search finds the relevant transcript across your library. Timestamp-capable modes can link back to the source moment.
Works in your language
Broad multilingual transcription and translation. Exact language and mixed-language support depends on the selected mode.
Know who said what
Speakers mode separates voices automatically. Rename "Speaker 1" to real names for clean meeting minutes.
Your format, your way
Export as TXT, PDF, DOCX, SRT, or VTT. Share via link, organize in folders, collaborate with your team.
Built for people who learn from video and audio
Right where you watch — a lecture hall, a newsroom, or a meeting room.
Students
Turn supported lecture recordings into searchable notes and generate flashcards for exams.
Notes, chapters & flashcards
Researchers
Transcribe interviews, code qualitative data, search across hundreds of recordings for specific quotes.
Semantic search across recordings
Journalists
Turn press conferences and interviews into answers on deadline. Export as text or SRT. Cite exact timestamps.
~30s On-device or on-demand per audio hour
Teams
Use Speakers mode for labelled meeting transcripts. Share folders with colleagues. Search across team recordings.
Speaker separation available
EU storage. Privacy-first processing.
Sensitive recordings deserve more than fine print. Here's what that means in practice.
EU storage
Account data, transcripts, and retained playback media use EU-configured storage.
Deleted by default
Source media is removed after transcription unless you choose to keep a playback copy.
Not our training data
Silestis does not sell your content or use it to train its own models.
Encrypted & private
Encrypted in transit; transcripts are tied to your account and shared only when you choose.
Pay for what you use. Cancel anytime.
Start with 100 one-time credits for up to 3 successful transcriptions. Upgrade when you need more — no commitment.
Free
See if you like it
- Up to 3 successful transcriptions (lifetime)
- 100 credits (lifetime) — about 2 full 30-min Fast recordings
- Fast model only
- Videos up to 30 min each
- TXT, SRT, VTT export
Go
For students & creators
- 2,000 credits / month (≈ 2,000 On-device or 1,000 Long & Flexible min)
- 50 transcriptions / month
- Fast + Long & Flexible
- Videos up to 2 hours
- 10 GB saved playback audio
- Transcript chat: 20 AI requests / 24h
- Flashcards for studying
- All export formats
Pro
For professionals
- 5,000 credits / month (≈ 5,000 On-device or 2,500 Long & Flexible min)
- 200 transcriptions / month
- All 3 cloud transcription modes
- Videos up to 5 hours
- Speaker diarization
- Chat & AI search: 100 shared requests / 24h
- Notes, chapters, action items & Work Products
- Folder sharing
- 50 GB saved playback media
- Everything in Go
Max
For power users
- 20,000 credits / month (≈ 20,000 On-device or 10,000 Long & Flexible min)
- 500 transcriptions / month
- Videos up to 10 hours
- 200 GB saved playback media
- Up to 10 simultaneous jobs
- Chat & AI search: 200 shared requests / 24h
- Everything in Pro
Questions? Answers.
What can Silestis do that ChatGPT or NotebookLM can't?
General AI tools need a public URL, an existing transcript, or a file you upload. Silestis adds a browser workflow for supported lecture portals, webinars, cloud-drive videos, and other sources you can already access. It does not bypass logins, paywalls, DRM, or source permissions.
Does it work on videos with no transcript, or behind a login?
Silestis supports many videos without an existing transcript and many authenticated sources, including common lecture and cloud-drive platforms. Support depends on the site's player and stream format. Silestis does not bypass DRM, paywalls, logins, or source permissions.
How fast can I get answers from a video?
Videos with usable captions can return text in seconds. AI transcription time varies with source duration, selected mode, media format, and current service load; jobs continue in the background while you work.
Do I need to upload or paste anything?
Not for supported browser sources. The Safari extension, included with the Silestis Mac app, can start the workflow from the page you are watching. Chrome is coming next; join the Chrome launch waitlist at /chrome/. You can also paste a supported link or upload a file in the web app.
Is my data secure?
Files are encrypted in transit, and account data, transcripts, and retained playback media use EU-configured storage. Source media is deleted after transcription by default. AI processing may use vetted providers outside the EU under appropriate transfer safeguards.
Which languages are supported?
Silestis supports broad multilingual transcription and translation, including English, German, French, Spanish, Chinese, Japanese, Korean, Arabic, and more. Exact source languages, translation directions, and timestamp support depend on the selected mode.
What happens after my 3 free transcriptions?
Your existing transcripts, chats, notes, and flashcards stay in your account. To transcribe more, upgrade to Go (€8.99/mo), Pro (€19.99/mo) or Max (€44.99/mo), all prices incl. VAT. Annual billing saves about 25% compared with paying monthly. Cancel anytime.
Can I ask questions about YouTube videos and podcasts?
Yes. Open a supported YouTube, TikTok, Vimeo, Instagram, or SoundCloud page and use Silestis for a transcript, summary, and timestamped answers when the selected mode provides timestamps. Link support varies by source, permissions, and stream format.
See where Silestis fits your workflow
Compare it to the tools you know, or jump straight to your use case.
Guides
- For the videos general AI tools often can't open directly
- How to summarize a YouTube video without downloading it
- Can ChatGPT summarize a YouTube video? When you need Silestis instead
- How to get timestamped answers from a podcast
- How to search inside a long video or lecture
- How to ask questions about supported online video
- How to turn a lecture into study notes
- How to transcribe a video in Safari
- How to export SRT or VTT subtitles
Compare Silestis
Use cases
Start from the supported lecture page you already use.
Open the video and click Silestis to start a transcript, summary, and notes workflow on the page. Timestamp-capable modes can also return cited answers, including when no source transcript exists.
Get the Safari Extension