Peek is a browser extension that shows previews for links to files and supported services in web pages. Just hover your mouse over a link, and Peek will display a small popup with an interactive preview of the link's content. Peek can show previews for PDFs, Microsoft Office documents, YouTube video links, audio files, Google Docs, and much more. It uses the browser's built-in rendering features, in combination with the Google Docs Viewer, Microsoft Office Web Viewer, and other third-party embedded viewers to display rich previews. Supported file types:

PDF, TXT, and RTF documents
WebM, MP4, M4V, OGG, OGV, and Imgur GIFV video
MP3, M4A, OGA, OGG, and WAV audio
Word documents (.doc, .docx)
Excel spreadsheets (.xls, .xlsx)
PowerPoint files (.ppt, .pptx)
OpenDocument files (.odt, .ods, etc.)
JPG, PNG, APNG, SVG, GIF, ICO, and BMP images

Supported links:

Google Docs links
iCloud Keynote links
YouTube videos and Shorts
Reddit links
Imgur links
TikTok videos
Mastodon posts
Facebook posts
Instagram posts and reels
Threads posts
Spotify tracks, albums, and podcast episodes

Peek is built to be private and secure. Check the Privacy Policy for more information. The code is open-source on GitHub.