Comparison

Sidenote vs ChatDOC

Both let you ask a document questions and both cite their answers. The difference is where you work: ChatDOC loads a file or a fetched web page into its own reading viewer, while Sidenote is a browser side-panel reader that reads the page you already have open — including pages behind your login — and cites it in place.

Sidenote

A reader that rides along in your browser, on the page you're already on.

ChatDOC

A document chat viewer you load files and fetched web pages into, then chat with them there.

The short answer

Should you use Sidenote or ChatDOC?

Choose Sidenote if…

You read across PDFs, private Confluence, Notion and SharePoint pages, and live web articles, and you want answers in place — no separate viewer — with citations that scroll the real page to the exact passage and a server-side check that drops unsupported claims.

Choose ChatDOC if…

You want cross-file querying over unlimited files and folders, EPUB and Markdown support, or a developer API to build document parsing and chat into your own product.

Plenty of people use both. They solve overlapping problems from different ends — one is a viewer you load documents into, the other rides along with your reading.

Compared honestly

Sidenote vs ChatDOC: feature by feature.

CapabilitySidenoteChatDOC
Reads the page or document you already have open Yes Partial
Works on private Confluence, Notion & SharePoint pages Yes No
Works on web articles & live web pages Yes Partial
Citations scroll & highlight the exact passage Yes Partial
Server-side citation check drops unsupported claims Yes No
One-click glossary of jargon & acronyms Yes No
Ask across many documents at once Yes Yes
Reads scanned PDFs with built-in OCR Yes Yes
Per-document Store / Discard retention control Yes No
Upload your own PDFs Yes Yes
Developer API No Yes
Reads EPUB e-books No Yes

Two rows go to ChatDOC, and we are not pretending otherwise — see Where ChatDOC is the better tool below. ChatDOC's Chrome and Edge extension can open a local PDF or a web page you're on, which is why the top row is a partial rather than a no; but it loads that content into ChatDOC's own viewer to chat, whereas Sidenote reads and cites the live page in place. The cross-document row is powered by Sidenote Collections; ChatDOC earns its own yes there with unlimited multi-file and folder querying. The cross-document row is powered by Sidenote Collections.

The core difference

A viewer you load documents into, or a reader that rides along.

ChatDOC is a document chat viewer. You give it a PDF, DOC, scan, EPUB, or a web page URL, it processes the content, and you chat with it inside ChatDOC's own reader — its TapSource footnotes tap back to the source passage in that viewer. There's a Chrome and Edge extension that can open a local PDF or the page you're on, but it still loads that content into ChatDOC to chat with it. It does that job well; it's just a separate reading surface from the documents in your day.

Sidenote never asks you to leave the page. It sits in the side panel of every tab, reads what you already have open — a PDF, a private Confluence runbook, a Notion doc, an article — and answers in place. Click a citation and it scrolls the real, live page and highlights the exact passage, not a copy inside another viewer. Every cited quote is validated on the server against the document, and anything it can't ground is dropped before you see it.

The difference in one example

Take a private Confluence runbook behind your company login. ChatDOC works on files you give it or public web pages it fetches on its own servers, so a page that only exists inside your signed-in session is out of reach. Sidenote runs in your browser on your session, so it reads exactly what's on your screen — and cites it back on that same live page.

Giving credit

Where ChatDOC is the better tool.

ChatDOC is a genuinely strong, accuracy-focused document chat tool. If these are what you need, it's the better choice:

Developer API

ChatDOC offers an API — and a standalone PDF Parser — so you can build document parsing and chat into your own product or workflow. Sidenote is an end-user reading assistant, not a platform you build on.

Deep multi-file workspaces

Unlimited files organised into unlimited folders, all queryable together — upload a whole folder and chat across every file at once. Built for people who live inside a large document library.

Broad file support including EPUB

Alongside PDF, DOC and DOCX, ChatDOC's Pro plan handles EPUB, Markdown, plain text and scanned files, so e-books and other formats are first-class citizens.

FAQ

Sidenote vs ChatDOC — common questions

If you mostly load standalone files into one viewer and chat with them, ChatDOC is a focused, accuracy-minded tool. If you read across PDFs and the wider web — Confluence runbooks, Notion docs, SharePoint files, articles, arXiv papers — and want answers in place with citations that scroll the live page to the exact passage, Sidenote is the better fit because it rides along in your browser instead of asking you to load everything into a separate viewer first.
No. ChatDOC works on files you give it or public web pages it fetches on its own servers — it can't sign in as you, so a page behind your company login is out of reach. Sidenote runs inside your browser on your own session, so it reads what's on your screen, including private wikis and intranet pages.
Yes. ChatDOC's TapSource links each answer back to the source passage and highlights it inside its viewer, which is a real strength. Sidenote adds two things: every answer is checked server-side against the passages actually retrieved, so unsupported claims have their citation dropped before you see them; and clicking a citation scrolls the real, live document and highlights the exact sentence.
Yes — a couple of things. ChatDOC offers a developer API for building document chat into your own product, supports EPUB e-books, and lets you organise unlimited files into unlimited folders queryable together. Sidenote is a desktop browser extension with no API and no EPUB support, focused on cited reading in place.
Of course. Some people keep ChatDOC as a workspace for a big library of loaded files, or use its API, and use Sidenote for everything they read in the browser day to day. They overlap, but they're not the same shape of tool.
Both have a login-based free tier. Sidenote is free to install with a 7-day Pro trial that needs no card; paid plans start at £10/month. ChatDOC has a free tier (a couple of PDF uploads a day, capped pages) and a Pro plan at roughly $8.99/month, or about $89.90 billed annually.
Try it on the page you are on

Read anything. With citations.

Add Sidenote to Chrome and ask the document in front of you a question. No separate viewer, no new tab — just the answer, and the passage on the live page that proves it.

7-day Pro trial · No card required · Free tier forever