The story behind Sidenote.

Useful AI you can actually check.

Most document AI is fluent, confident, and sometimes quietly wrong. Sidenote was built around the opposite instinct: every answer is forced to cite the passage it came from, the server validates those citations, and anything it can't ground is dropped. Click a citation and the page scrolls to the exact source. If the document doesn't answer your question, it says so.

That same idea now runs across the tools you already use — Confluence, Notion, SharePoint, Google Docs, PDFs and the web — so you get one assistant that reads everything and cites everything. See how citations work or every source it reads.

A solo, independent UK product.

Sidenote is designed, built and supported by Lewis Hadden, a solo developer in the United Kingdom, trading as Sidenote. No venture backing and no growth team — just a focused product and a real person reading every support email. That's deliberate: it keeps the incentives simple and the product honest.

Private by default.

Your documents are never used to train AI models. Data is stored in a UK region (eu-west-2), encrypted at rest, and isolated per account. Connected accounts are read-only and per-document, and disconnecting one deletes its tokens immediately. The full detail is in the privacy policy and security page.