Sidenote

Overview

Sidenote is an AI reading assistant for asking questions about documents in a browser and tracing answers back to their source passages. It suits readers who work across PDFs and connected workspaces and want summaries, notes and searchable collections alongside document chat.

Its strongest distinction is the citation workflow: answers point to passages that readers can jump to and inspect. The trade-off is a tiered set of quotas and a compliance gap for organizations that require SOC 2.

Key features

Citations do more than label an answer: clicking one scrolls to and highlights the supporting passage. That makes Sidenote more useful for checking claims than a summarizer that returns only a condensed account, though readers still need to judge whether the cited passage supports the answer.

Reading tools include summaries, explanations, glossaries, document search, notes, highlights, tags and starred documents. Multi-document collections let readers group related material, while uploaded files can be PDF, DOCX, PPTX, TXT, MD, MDX or RTF. Sidenote also reads browser-rendered PDFs, including scanned PDFs with OCR. Short summary-length control and Markdown export provide some flexibility, but do not imply broader export options.

Dedicated integrations connect Confluence, Notion, Google Docs, Slack canvases, SharePoint and OneDrive. Confluence indexing is separately capped on eligible paid plans, so the integration list should not be read as unlimited indexing. The 7-day Pro trial needs no card, but its 10-document, 20-summary and 10-chat-turn limits make it a bounded preview rather than an open-ended evaluation.

The maker says user content is not used to train AI models and its AI providers use no-training defaults on the API tiers involved. Documents are stored in Supabase’s UK eu-west-2 London region, encrypted at rest and isolated by account with row-level security. Users can keep documents while their account is open or choose Discard, which purges a document within 24 hours; library documents can also be deleted at any time. Sidenote is not yet SOC 2 certified, a material drawback for buyers whose procurement rules require that attestation.

Pricing

The Free plan costs nothing, billed forever. It allows 3 documents per month at 5 MB each, 10 summaries, 10 explanations, 3 glossary builds and 10 chat turns per month. With no collections or Confluence space indexing, it is best for occasional individual reading, not an ongoing team library.

Pro costs £10 a month, billed monthly. It raises the caps to 25 documents per month at 20 MB each, 75 summaries, 70 explanations, 15 glossary builds and 35 chat turns, with collections of up to 5 documents. This is the clearest fit for a regular solo reader; the Free plan’s smaller quotas and lack of collections are the meaningful sacrifices.

Pro+ costs £20 a month, billed monthly, and doubles many Pro allowances: 50 documents at 40 MB each, 150 summaries, 140 explanations, 30 glossary builds and 50 chat turns per month. Collections can hold up to 10 documents, and Confluence indexing is capped at 200 pages per month. It suits heavier individual use, but the step up is worthwhile only if those larger quotas matter.

Pro Max costs £100 a month, billed monthly. Its 250 documents at 75 MB each, 750 summaries, 700 explanations, 150 glossary builds and 250 chat turns per month, plus collections of up to 25 documents and 500 indexed Confluence pages, target high-volume work rather than ordinary reading. Team costs £18 a month, billed monthly, or £14.40 a year, billed annually. Both Team plans provide Pro-level caps per member, shared team collections and SAML SSO with domain auto-join; team owners and admins receive Confluence indexing at 500 pages per month. The annual option costs less per stated billing term, while the monthly option avoids an annual billing commitment. Team does not raise each member’s Pro caps.

Platforms

Sidenote is available as a browser extension and on the web. The site lists Chrome, Edge and Firefox extensions; Opera is described as coming soon. This suits browser-based document work, but does not amount to a listed native mobile app.

Who it's for

Sidenote is a good match for researchers and for engineering, product, customer success, legal and operations teams that need to query documents and verify answers against passages. Individuals can start on Free or move to Pro as monthly reading outgrows the caps. Teams that need shared collections or SAML SSO have a dedicated tier, but organizations that require existing SOC 2 certification should look elsewhere.

Pros and cons

• Pros: Clickable citations take readers directly to highlighted source passages, making answer-checking concrete.
• Pros: OCR for scanned browser-rendered PDFs and support for common office, text and Markdown file types broaden its usefulness beyond clean web pages.
• Pros: Store or Discard retention choices, account-level isolation and deletion controls give users practical control over documents.
• Cons: Monthly quotas apply across core activities, and Free allows only 3 documents and no collections, limiting sustained or collaborative use.
• Cons: Pro Max costs £100 a month, a substantial commitment suited to high-volume quotas rather than typical personal reading.
• Cons: Sidenote is not yet SOC 2 certified, which can rule it out under formal compliance requirements.

Alternatives

For a broader selection of tools in this category, browse AI Summarizers.

• Choose Scholarcy if its free article summarizer and one-at-a-time flashcard export better fit an article-focused workflow.
• Choose smry if you want a free option spanning extension, iOS and web.
• Choose SMMRY if a web or API summarizer with a free monthly allowance is a closer fit.
• Choose Kagi Summarize if you prefer a paid service without a free plan and need its listed Android, iOS, API, extension and web platforms.
• Choose genei if its free Chrome webpage summarizer or listed PDF and webpage import on Genei Basic better matches your reading.
• Apogee is a free, extension-only alternative.
• Choose Summify if you want an iOS or web option with daily analyses and Learn cards.
• Choose Lemora if you need listed Android, iOS, macOS or Windows apps alongside web access.

Verdict

Choose Sidenote if your work involves asking questions across documents and you want to verify answers by jumping to their cited passages. Its mix of file support, retention controls and connected workspaces makes it more than a one-click summarizer. Look elsewhere if your organization requires SOC 2 certification, if you need a listed mobile app, or if the monthly document and interaction caps do not suit your workload.