About half of Notion's supported embed types are generic iframes. The rest either have edge cases, custom formatting, or use a third-party script to embed content.

YouTube

Twitter

(uses the official Twitter embedding SDK)

Spotify Playlist

Spotify Podcast

Spotify Podcast 2

Spotify Preserve Scale

Google Maps

Figma

Loom

SoundCloud

Airtable

Google Drive (Doc)

Google Drive (Sheet)