Sidenote - 2026 Pricing, Features, Reviews & Alternatives

Sidenote is an AI reading assistant that runs in the browser side panel and turns any document into something you can question, summarize, and verify without leaving the tab.

Core functions:

- Summarize with citations: TL;DR bullets, a tight paragraph, or a structured deep read. Every key point carries a numbered citation chip.

- Chat with documents: answers stream in live, grounded in the open document, with citations back to the supporting passage. Clicking a citation scrolls the source into view and highlights it.

- Explain and glossary: explain difficult passages at different reading levels and build a one-tap glossary of jargon.

- Collections: group documents and run summaries, chat, and glossaries across the whole set. Answers cite which document said what.

Supported sources: web articles, PDFs including scanned files with built-in OCR, Confluence wikis, Notion pages, Google Docs, SharePoint and OneDrive files via Microsoft Graph, Gmail attachments, arXiv papers, Slack canvases, and direct uploads of Word and PowerPoint files.

Integrations: Google Drive and Google Docs, Microsoft SharePoint and OneDrive, Confluence, Notion, Gmail, and Slack. The Slack app answers questions across a team's saved documents from inside Slack. Google Docs access is read-only.

Security and privacy: data is hosted on UK-based servers with row-level security enforced at the database layer. Store mode retains documents for the life of the account; Discard mode purges document content within 24 hours. Shared links are static snapshots that can be revoked at any time.

Platforms and languages: Chrome, Edge, and Firefox extensions, plus a web viewer and Slack integration. The interface supports 17 languages. Cached documents reopen without consuming additional quota.