Answers from the videos AI can't reach
No transcript? Behind a login? Silestis works right on the page you're watching — lectures, webinars, SharePoint, Drive, course portals — where ChatGPT and NotebookLM can't. One click gives you a summary, timestamped answers, and notes; everything else you watch becomes a searchable memory.
[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...
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
No upload, no copy-paste — the extension grabs the audio on the page. A one-hour recording is ready in about 30 seconds.
Get answers — and a searchable memory
Ask questions and get timestamped answers. Generate summaries, notes, and flashcards. Everything you capture becomes a searchable memory you can ask across.
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? Answered in about 30 seconds
When there's no caption to lean on, Silestis transcribes the audio on the page with 6 AI models optimized 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. Like ChatGPT for any video or podcast you find online.
Instant structure from any recording
AI generates structured notes, chapter marks, and key-point flashcards — from meetings, interviews, or lectures.
A searchable memory of everything you watch
"What did the professor say about the exam?" — Semantic Search finds the exact moment across everything you've captured. No more scrubbing through hours of audio.
Works in your language
100+ languages. Transcribe a German call, translate to English, or handle mixed-language recordings — all automatic.
Know who said what
Meeting mode detects each speaker. 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 lecture recordings into searchable notes. Generate flashcards for exams. Never miss what the professor said.
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 per hour of audio
Teams
Document meetings with speaker labels. Share folders with colleagues. Search across all team recordings.
Speaker detection built in
Your audio never leaves the EU
Sensitive recordings deserve more than fine print. Here's what that means in practice.
EU-hosted
Processed on Cloudflare's EU edge and stored in the EU — built for GDPR from day one.
Deleted after transcription
Source audio is removed once your transcript is ready. We keep the result, not the recording.
Never trains AI
Your recordings and transcripts are never used to train models. Your content stays yours.
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 3 free transcriptions and 70 lifetime credits. Upgrade when you need more — no commitment.
Free
See if you like it
- 3 transcriptions (lifetime)
- 70 credits (lifetime)
- Fast model only
- Videos up to 15 min
- TXT, SRT, VTT export
Go
For students & creators
- 2,000 credits / month
- 50 transcriptions / month
- Fast + Gemini long-form/translation
- Videos up to 2 hours
- 10 GB saved audio playback
- AI Chat with transcript
- All export formats
Pro
For professionals
- 5,000 credits / month
- 200 transcriptions / month
- All 6 models (incl. Cohere best quality)
- Speaker diarization
- Semantic search
- Notes, Chapters & Flashcards
- Folder sharing
- 50 GB saved playback media
- Everything in Go
Max
For power users
- 20,000 credits / month
- 500 transcriptions / month
- Videos up to 10 hours
- 200 GB saved playback media
- Up to 10 simultaneous jobs
- Higher chat & search rate limits
- Everything in Pro
Questions? Answers.
What can Silestis do that ChatGPT or NotebookLM can't?
ChatGPT, NotebookLM and Perplexity can only work with content they can reach — a public URL, an existing transcript, or a file you upload. They can't reach a gated lecture portal, a webinar behind a login, or a SharePoint, OneDrive, or Drive video — and for a video with no transcript, the only way to feed it to them is to download and upload it yourself. Silestis runs in your browser on the page you already have open, captures it there, transcribes it when there's no caption, and turns it into answers. For public YouTube with captions, those tools work fine — Silestis is for everything they can't reach.
Does it work on videos with no transcript, or behind a login?
Yes — that's the point. If you can play the video in your browser (a Panopto/Zoom/Kaltura lecture, a webinar, a SharePoint/OneDrive or Google Drive video), Silestis works on it right on the page, and transcribes the audio when there's no caption to use. You only ever process content you already have access to, in your own session — Silestis doesn't bypass DRM, paywalls, or permissions.
How fast can I get answers from a video?
Fast — a one-hour recording is typically ready in about 30 seconds. You're already on the page, so one click gives you a summary, timestamped answers, and notes. Videos with existing captions can return text in seconds.
Do I need to upload or paste anything?
No. With the Silestis extension for Safari and Chrome you stay on the page you're watching and get answers with one click — no downloads, no copy-paste. You can also paste a link or open the web app if you prefer.
Is my data secure?
Yes. Files are processed on Cloudflare's edge network (EU), encrypted in transit, and stored in Cloudflare R2. Audio files are deleted after transcription. We never sell or share your data.
Which languages are supported?
Over 100 languages including English, German, French, Spanish, Chinese, Japanese, Korean, Arabic, and more. Translation between languages is built in.
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). Annual billing saves about 25% compared with paying monthly. Cancel anytime.
Can I ask questions about YouTube videos and podcasts?
Yes — open any YouTube, TikTok, Vimeo, Instagram, or SoundCloud video and click Silestis for a summary and timestamped answers, right on the page. You can also paste a link; 1800+ sites are supported via yt-dlp, with no download needed.
See where Silestis fits your workflow
Compare it to the tools you know, or jump straight to your use case.
Guides
- For the videos ChatGPT & NotebookLM can't open
- 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 any online video
Compare Silestis
- Silestis vs Google NotebookLM
- Silestis vs Otter.ai
- Silestis vs Notta
- Silestis vs Fathom
- Silestis vs Fireflies.ai
- Silestis vs Tactiq
- Silestis vs Descript
- The NotebookLM alternative for video & audio
- Silestis vs free transcripts & doing it manually
- Silestis vs Rev
- Silestis vs Sonix
- Silestis vs TurboScribe
Use cases
The next lecture your AI tools can't open — Silestis can.
Open the video, click Silestis, done — a summary, timestamped answers, and notes, right on the page. Even when there's no transcript.
Get Started Free