Desk No. 05 · Lectures, webinars, training
AI video summarizer for lectures and webinars
For uploaded recordings, not YouTube. April 2026.
For uploaded recordings (MP4, WebM, MOV), Memories.ai and WayinVideo are the specialists. For meeting-style recordings with multiple speakers, Otter Pro produces the best speaker-tagged summaries. For YouTube recordings, see our YouTube summarizer review which has dedicated tooling for URL-based inputs.
§ I.Three use cases
Lecture recordings
Best tools: Otter Pro, WayinVideo
University lecture captures, MOOC recordings, training videos. Single presenter, structured content. Otter Pro's meeting-note format works well for linear lecture content.
Webinar archives
Best tools: Memories.ai, ScreenApp
Recorded webinars with presenter slides, Q&A sections, and panel discussions. Benefits from tools that handle multi-speaker content and can index across a library of recordings.
Training video libraries
Best tools: Memories.ai, WayinVideo
Corporate training content, product demo archives, onboarding recordings. Key use case: building a searchable library where employees can find relevant video clips by topic.
§ II.File format and length matrix
| Tool | Formats | Max length | Price | Speaker diarization |
|---|---|---|---|---|
| Memories.ai | MP4, WebM, MOV, MP3, M4A | Up to 5 hours | $9.99/mo | Yes (basic) |
| WayinVideo | MP4, MOV, AVI, WebM | Up to 3 hours | Freemium | Yes (basic) |
| ScreenApp | MP4, WebM, browser recording | Up to 2 hours | Free / $15/mo | No |
| Otter Pro | MP3, MP4, M4A, WAV (upload) | No stated limit | Mid-tier monthly | Yes (strong, trainable) |
| Fireflies Pro | MP4, MP3, M4A, WAV | No stated limit | Low monthly tier | Yes (good) |
| tl;dv | Zoom cloud recordings, Google Meet | No stated limit | Free / $18/mo | Yes (basic) |
Format support and limits verified April 2026.
§ III.Common questions
Q.01Can AI summarize an MP4 video file?
Yes. Tools like Memories.ai, WayinVideo, and ScreenApp accept MP4 and other common video formats via direct upload. The AI transcribes the audio track and generates a summary from the transcript. Quality depends on audio clarity: videos with clear speech and minimal background noise produce much better transcriptions and summaries than those with music, multiple overlapping speakers, or poor recording quality.
Q.02What is the best AI for lecture recording summarization?
For university lecture recordings, Otter Pro is the best combination of transcription accuracy and meeting-note format. Upload the MP4 or connect to your lecture capture system. For YouTube lecture recordings, NoteGPT or Eightify work directly from the URL. For private lecture archives you want to build a searchable library from, Memories.ai or WayinVideo support batch upload and multi-video search.
Q.03How does AI video summarization handle multiple speakers?
Speaker diarization (the ability to distinguish and label different speakers) is the key differentiating feature. Otter Pro has strong speaker diarization and can be trained to recognise specific voices. Fireflies and tl;dv both support speaker labels for meeting-style content. General video upload tools (Memories.ai, WayinVideo) have weaker speaker diarization because they are not specialised for multi-speaker conversational content.