Sidenote is an AI reading assistant that lives in your browser's side panel and answers questions about whatever you're reading — a PDF, a web article, a Confluence page, a Notion doc, a Google Doc, a SharePoint file, or anything you upload. Every answer cites the exact passage it came from. Click a citation and the document scrolls to the source and highlights it, so you can check the answer in one click instead of taking the AI's word for it.
Most document AI is fluent, confident, and occasionally wrong. Sidenote is built around the opposite instinct: the model has to cite every claim, the server validates each citation against the source text, and anything it can't ground in the document is dropped before the answer reaches you. No silent hallucinations, no guessing at what a runbook or contract clause actually says.
Your documents are scattered across half a dozen tools, and each one wants to sell you its own AI add-on. Sidenote reads them all from a single browser extension — no per-platform seats, no admin rollout. Group related documents from different sources into a Collection and ask one question across all of them, with each answer citing the specific document it drew from. It's used by engineering teams querying runbooks and postmortems, product managers synthesising across PRDs and research, customer success pulling cited answers from knowledge bases, and legal and ops teams quoting the exact clause instead of guessing — and it works just as well on an arXiv paper or a long-form article.
Privacy is a default, not an upsell. Your data is stored encrypted in the UK, isolated to your account, and never used to train models; connectors are read-only, and you can purge documents within 24 hours or delete your account and everything in it yourself. Start free or on a seven-day Pro trial — no card required.
Key capabilities
Cited chat — ask questions about any document and get streamed answers with inline citations that scroll and highlight the source passage
Summaries — TL;DR bullets, standard, or detailed deep-reads, with every point cited
Explain simply — rewrite dense passages in plain language at the reading level you choose, without losing accuracy
Glossary builder — auto-generate a glossary of a document's terms, jargon, and acronyms, each entry cited to where it's defined
Collections — combine documents from different tools into one workspace and ask a single question across all of them
Works everywhere you read — PDFs, web pages, Confluence, Notion, Google Docs, SharePoint & OneDrive, Word and PowerPoint files, Slack canvases, and drag-and-drop uploads
Slack app — ask your library or run a semantic search from Slack; answers stream back privately with citations, and any message can be saved as a source
Cross-browser — Chrome, Edge, Firefox, and Opera
Private by design — UK data residency, encryption at rest, per-user isolation, no model training on your content, and self-serve deletion
