Gemini Notebook (NotebookLM) vs Microsoft Copilot Notebooks: what's actually different

Microsoft's Copilot Notebooks, built into Microsoft 365 Copilot and OneNote, gathers your chats, files, and links into one scoped workspace and answers questions grounded only on what you added, the same pitch Google made for NotebookLM (renamed Gemini Notebook in July 2026) years earlier. Reviewers keep framing the two as "not really competing," which undersells how directly Copilot Notebooks was aimed at NotebookLM's territory. This comparison covers the parts existing write-ups leave out: the real source-limit numbers, the actual cost once you add up licensing, and which one wins on citation accuracy.

What each product actually is

Gemini Notebook is a standalone research tool: you add sources (documents, PDFs, web pages, YouTube videos, audio files), and it answers questions strictly grounded in what you added, with inline citations pointing back to the exact source passage. It also generates Audio Overviews (AI-hosted podcast-style discussions of your sources), video overviews, mind maps, quizzes, and slide decks.

Copilot Notebooks, per Microsoft's own documentation, lives inside the Microsoft 365 Copilot app (at m365.cloud.microsoft) and also opens inside OneNote for a fuller editing experience, Microsoft explicitly recommends using both together rather than picking one. A notebook gathers Copilot Chat threads, files, OneNote pages, meeting notes, and web links into one scoped context, then answers only from that content. It generates an auto-summary "Overview," an Audio Overview, infographics, mind maps, and quick-create outputs like drafts and flashcards.

Source limits: what Microsoft's own pages disagree on

This is messier than any single number can capture, and worth stating plainly rather than picking one figure and moving on. Microsoft licenses Copilot Notebooks two ways: a lighter Copilot Chat tier and the full Microsoft 365 Copilot tier, and the reference limit differs by which one you have. Per Microsoft's own how-to-add-references documentation, Copilot Chat users can add up to 50 references and all 50 are used for grounding. Full Copilot users can add more than 300, but only the first 300 are used.

                          Gemini Notebook              Copilot Notebooks
--------------------------------------------------------------------------------
Standard/lower tier         50 sources (free            Copilot Chat: up to 50
                             Standard tier)                references, all used for
                                                            grounding

Top consumer/enterprise    300-600 depending on          Full M365 Copilot: 300+ can
  tier                      plan (Pro/Ultra)               be added, first 300 used

Source: Google and Microsoft's own support documentation, verified 21 Aug 2026.
Gemini Notebook figures are secondary-source aggregates; verify against
support.google.com/gemininotebook before treating as exact.

Where it gets genuinely inconsistent: separate Microsoft support pages and community answers don't agree on that full-Copilot number either. One Microsoft documentation page states all 300 added references get used for grounding; other Microsoft-adjacent community answers put the real grounding ceiling closer to 100, with anything beyond that added but silently unused. We could not find one authoritative Microsoft page that resolves this discrepancy, so treat any single confident number, including ours, with caution, and expect Microsoft's own docs to keep shifting as the feature (still marked as evolving in its own FAQ) matures. We also could not confirm a hard per-upload-action cap in Microsoft's current documentation; if you've hit one in practice, it may be a UI batching limit rather than a documented rule.

Source types and what's missing

Gemini Notebook accepts Google Docs and Slides, pasted text, public URLs, YouTube links, PDF, TXT, Markdown, audio files, image files, DOCX, PPTX, and XLSX. Copilot Notebooks accepts .docx, .pptx, .xlsx, .pdf, OneNote pages (.page), Loop components, and web URLs, but no YouTube support at all, a real gap if any of your source material is video. Pointing Copilot at a whole SharePoint or OneDrive folder instead of individual files triggers a different behavior entirely: it auto-selects up to 300 of the most relevant files itself, rather than using everything you have access to.

Audio Overviews: 8 languages vs 80+

Both products generate an AI-hosted audio discussion of your sources, but the depth differs sharply. Gemini Notebook offers four distinct formats, per Google's support documentation: Deep Dive (two hosts, the default), Brief (a single host, under two minutes), Critique (two hosts evaluating your work), and Debate (a formal two-host debate), in more than 80 languages, with a custom-prompt option to steer focus or expertise level. Copilot's Audio Overview, confirmed via Microsoft's own feature page, supports 8 languages (English, Spanish, Japanese, French, German, Portuguese, Italian, Chinese) with a single format and no confirmed equivalent to Gemini Notebook's four distinct styles.

Citation accuracy: one open complaint worth knowing about

One data point worth flagging, though it needs a caveat before you weigh it. Microsoft's Learn Q&A community) has a thread titled "Citations consistently wrong in M365 Copilot," where one user describes testing that found a majority of responses contained at least one incorrect citation, in some cases pointing to a source unrelated to the claim. This is a single person's self-reported, unverified testing about general Microsoft 365 Copilot chat behavior, not a Copilot Notebooks-specific study and not an official Microsoft finding, so treat it as one open complaint rather than a documented product gap. It's still a reasonable point in Gemini Notebook's favor structurally: its design refuses to answer outside your added sources at all rather than blending in outside knowledge, which leaves less room for a citation to point somewhere wrong in the first place, but that's a design-based inference on our part, not a head-to-head measurement of the two products.

What each one costs, all-in

Neither product is sold on its own; both ride on a broader subscription, which is where total-cost comparisons usually go wrong by quoting only the add-on price:

                     Gemini Notebook                    Copilot Notebooks
--------------------------------------------------------------------------------
Free option           Yes: Standard tier, 50 sources     No standalone free tier, but
                                                            Copilot Chat (a lighter,
                                                            often already-bundled tier
                                                            for many M365 subscribers)
                                                            gets you 50 references too
Consumer price        $4.99/mo (AI Plus) or               ~$19.99/mo (Microsoft 365
                       $19.99/mo (AI Pro), whole-           Premium, consumer bundle
                       Gemini-ecosystem plan                including Copilot)
Enterprise price       Bundled into Google AI Ultra         Full Copilot: $30/user/month
                       (20TB/30TB) or Cloud                 ADD-ON on top of a qualifying
                       Enterprise licensing                 base Microsoft 365 plan, real
                                                              per-seat cost commonly
                                                              $66-$87/user/month all-in

Source: Google and Microsoft pricing pages, verified 21 Aug 2026.

The headline $30/user/month figure is for the full Microsoft 365 Copilot add-on and understates the real cost, since it requires an eligible base Microsoft 365 plan underneath it; independent pricing trackers put the true all-in enterprise cost closer to $66 to $87 per user per month. What most comparisons miss is that Copilot Notebooks is also reachable through the lighter Copilot Chat tier, which many organizations already have bundled at lower or no incremental cost, and which gets the same 50-reference grounding limit as the full tier's lower band. If your organization already has Copilot Chat access, Notebooks may effectively cost nothing extra to try, closer to Gemini Notebook's free-tier proposition than the $30 add-on price suggests on its own.

Mobile, editing, and workflow friction

Gemini Notebook has dedicated iOS and Android apps (a lighter-featured "Lite" version on mobile); Copilot Notebooks has no native mobile app at all, web and Windows OneNote only. On editing, the relationship flips: OneNote's note editor is more full-featured, with slash commands and a modern block-based interface, while Gemini Notebook's own note editor is comparatively basic. Workflow-wise, Gemini Notebook opens a cited source in a non-disruptive side panel; Copilot Notebooks tends to open sources in separate windows, which several hands-on reviews flagged as breaking flow during active research.

Data handling and training

Both vendors make the same core promise: neither trains its underlying model on your notebook content. Microsoft's FAQ states plainly that "Copilot Notebooks doesn't use user data to train the large language model" and that Copilot "doesn't access your entire OneDrive, email, Teams chats, or the web," only the references you explicitly added. Google states an equivalent no-training policy for Gemini Notebook. The meaningful enterprise difference isn't training, it's governance surface: Copilot Notebooks inherits Microsoft 365's existing compliance boundary (sensitivity labels, DLP, eDiscovery) automatically, something consumer-tier Gemini Notebook doesn't natively offer. Google's answer to that gap is a separate product, Gemini Notebook Enterprise, run through Google Cloud with its own VPC-SC, CMEK, and audit-logging setup, so the comparison isn't consumer-vs-enterprise by default; it's a matter of which product tier you're actually buying.

The practical decision rule

Skip the "they don't really compete" framing some reviews reach for; both tools now do grounded Q&A over a bounded source set with citations and audio overviews, they compete directly. The decision that actually matters: if your organization already pays for a Microsoft 365 Copilot seat, Copilot Notebooks is a marginal-cost add, and it wins on SharePoint/OneNote-native workflows and inherited compliance controls. If you don't already have a Copilot seat, Gemini Notebook's free tier gets you started with no procurement step, broader source types, more output formats, and a native mobile app, at the cost of a plainer note-editing experience. A common real-world pattern from hands-on write-ups: use Copilot for broad exploratory research inside your existing Microsoft workflow, then paste the findings into Gemini Notebook to build a curated, citable source base and generate audio overviews or mind maps from it.

People also ask

Is Copilot Notebooks free like NotebookLM's Standard tier?

No. Copilot Notebooks requires a Microsoft 365 Copilot or Copilot Chat license (consumer path through Microsoft 365 Premium at roughly $19.99/month, enterprise add-on $30/user/month on top of a qualifying base plan). Gemini Notebook has a genuine free Standard tier with 50 sources and the full Audio Overview feature set.

How many sources can Copilot Notebooks actually use?

It depends on your license: Copilot Chat supports 50 references, all used for grounding. Full Microsoft 365 Copilot supports 300+, but Microsoft's own documentation doesn't agree on whether all 300 or only around 100 are actually used to generate an answer, and we couldn't find a page that resolves the discrepancy. Nothing in the interface flags which sources make the cut.

Does Copilot Notebooks support YouTube videos as a source?

No. This is a real gap versus Gemini Notebook, which accepts YouTube links directly as a source type.

Which one is more accurate for citations?

One user's self-reported testing on a Microsoft Learn Q&A thread found frequent citation mismatches in general Microsoft 365 Copilot chat, though it's a single anecdotal report, not a Notebooks-specific or official finding. Gemini Notebook's stricter refuse-to-answer-outside-sources design should give it a structural edge on citation reliability, though that's a design-based inference rather than a measured comparison.

Can I use Gemini Notebook and Copilot Notebooks together?

Yes, and it's a common workflow: some users run broad exploratory research in Copilot (already embedded in their Microsoft 365 workday) and then paste the findings into Gemini Notebook to build a curated, citable source base with audio overviews or mind maps.

Does Copilot Notebooks work on mobile?

There's no native mobile app; it's web and Windows OneNote only. Gemini Notebook has dedicated iOS and Android apps, though the mobile version has a lighter feature set than the web app.

Is my data used to train AI models in either product?

Both vendors state they don't train their models on your notebook content. Verify Google's current wording on support.google.com/gemininotebook directly, since Gemini Notebook was renamed from NotebookLM in July 2026 and some pages may still be transitioning.