Plain note-taking on Android has been a solved problem for a decade. What changed in the last two years is that a note app can now read what you have written, find related notes you forgot about, summarize a 90-minute meeting transcript, and turn a brain dump into a usable outline. The seven AI note-taking apps for Android below are the ones where the model actually does work, not the ones that bolt on a chat bubble and call it AI.
For a broader cut without the AI lens, our best apps for note-taking and second brain apps for Android cover the underlying note app market. This list is narrower: each pick uses an LLM to transform notes in a way the non-AI version cannot.
What an AI note app actually does
Most apps in this category cluster around four use cases:
- Summarize long inputs. Meeting transcripts, PDFs, voice memos. The model collapses 10,000 words into the action items.
- Query your own notes. Ask “what did the legal team flag last quarter” and get an answer cited from notes you wrote.
- Generate structure. A bullet brain dump becomes a tagged outline with related notes linked in.
- Cross-source synthesis. Upload PDFs, articles, audio. Ask one question across all of it with citations back to the source.
We tested each app on Android with the same three jobs: a 45-minute voice memo (rambling product idea), a 120-page PDF (academic paper), and a year of accumulated meeting notes. The picks that follow are ranked by how well they handled all three, not by how much marketing copy each company writes about AI.
Quick comparison
| App | Best for | AI model | Free plan | Paid starts at |
|---|---|---|---|---|
| Microsoft OneNote | Mainstream notes plus Copilot | GPT-class via Copilot | Yes, full notes | $20/mo (Copilot Pro) |
| NotebookLM | Source-grounded synthesis | Gemini 2.5/3 | Yes, capped | $19.99/mo (Google AI Pro) |
| Notion | Database notes with AI | Multi-model (OpenAI, Anthropic) | 1 user, no AI | $10/mo + $10 AI |
| Obsidian | Local-first AI on your vault | Bring-your-own key | Yes, plugins free | API costs only |
| Mem | Auto-organizing AI notes | OpenAI-backed | Limited trial | $14.99/mo |
| Reflect | Fast notes with GPT assist | GPT-class | 7-day trial | $15/mo |
| Evernote | Legacy capture with AI Edit | OpenAI-backed | Yes, 50 notes | $14.99/mo |
The apps
1. Microsoft OneNote, best mainstream AI note-taking
Microsoft OneNote is the default pick because the underlying app has been a solid free notebook for fifteen years, and Copilot now sits inside it on Android. Drafts, summaries, rewrites, and Q&A across a notebook all happen in a side panel without leaving the page you are writing on. The model handles ink-and-text mixed pages, which most AI note apps still trip over.
The price story matters too. Anyone with a Microsoft 365 Personal or Family subscription already has Copilot built in, so the AI features cost nothing on top. Without 365, Copilot Pro at $20 per month is the standalone path. OneNote itself stays free for unlimited notebooks synced through OneDrive.
Where it falls short: Copilot inside OneNote works per notebook section, not across your entire OneNote library, so cross-notebook synthesis still needs a separate trip to Microsoft Copilot or Bing Chat. The Android tablet experience is sharper than the phone one, where the side panel covers the page on smaller screens.
Pricing:
- Free: unlimited OneNote, OneDrive sync, no Copilot.
- Microsoft 365 Personal: $9.99/month, includes Copilot in OneNote, Word, Excel.
- Copilot Pro: $20/month standalone if you do not want 365.
Platforms: Android, iOS, Windows, Mac, web.
Bottom line: Pick OneNote if you already use Microsoft 365 or you want a free notebook with a paid AI layer you can switch on later.
2. NotebookLM, best for source-grounded synthesis
NotebookLM is the AI note-taking app for people whose actual job is reading. Upload PDFs, slide decks, web pages, YouTube transcripts, and audio. Ask questions and get answers with footnoted citations pointing to the exact passage each claim came from. The Android app caught up with the web client over 2025 and now includes the Studio panel for Audio Overviews, the briefing podcast format Google made famous.
This is the only mainstream tool that refuses to step outside your uploaded sources by design. Hallucinations are rare because the model is forbidden from going freelance. For lit reviews, research projects, or any workflow where citations matter, that constraint is the whole product.
Where it falls short: Free tier caps sources per notebook at 50 and notebooks per account at 100. There is no cross-notebook search in NotebookLM itself, although the Gemini app can now mount a notebook as a source. Source-grounded design also means it does not work as a freeform brain dump tool, you have to write your notes somewhere else first.
Pricing:
- Free: 50 sources per notebook, around 3 Audio Overviews per day.
- Google AI Pro: $19.99/month bundles NotebookLM Pro, Gemini 3 Pro, and 2 TB storage.
Platforms: Android, iOS, web.
Bottom line: Pick NotebookLM when your notes are a research vault and you want grounded answers, not freeform AI rewrites.
3. Notion, best AI notes inside a database
Notion is the AI note-taking app for people who already think in tables. Notion AI sits inside every page, summarizes long docs, drafts and rewrites in your style, fills database properties from page content, and answers questions across your whole workspace. The Android app rebuilt the editor in 2025 so AI invocation feels native rather than a webview shim.
What makes Notion different from the freeform AI tools is the schema. A meeting note is not just a page, it is a row in a Meetings database with attendees, decisions, and action items as typed properties. Ask “summarize all customer calls last month where pricing came up” and the AI uses both the structured filters and the page contents. That is harder to replicate in any markdown-vault tool.
Where it falls short: Notion AI is a paid add-on at $10 per user per month on top of the regular plan, which gets expensive for solo users. Offline mode is partial, sync conflicts still happen, and AI features are cloud-only.
Pricing:
- Free: 1 user, unlimited pages, no AI.
- Plus: $10/user/month for sharing and unlimited file uploads.
- Notion AI: $10/user/month add-on for unlimited AI generations and Q&A.
Platforms: Android, iOS, web, Mac, Windows.
Bottom line: Pick Notion if you already organize work in databases and want AI that understands both rows and prose.
4. Obsidian, best local-first AI on your own vault
Obsidian is the AI note-taking app for people who refuse to send their vault to a third party. The base app stays free, the vault stays as plain markdown files on the phone, and AI arrives through plugins like Smart Connections, Copilot for Obsidian, and Text Generator. You bring your own API key, the model runs against your own notes, and the results stay local. Power users on XDA have written up workflows for running an entire Obsidian vault from a phone with Claude piping into the vault over MCP, which gives you something close to a personal coding agent for your second brain.
The other angle is choice. Smart Connections runs embeddings on-device against a quantized model if you want full offline AI, or against OpenAI, Anthropic, or local Ollama servers if you want the bigger models. Nothing else on this list gives you that range without forcing a subscription.
Where it falls short: Plugin setup is fiddler-grade on Android. Some heavier plugins do not run on mobile, and configuring API keys, sync, and model selection is a one-evening project rather than a one-tap install. There is no out-of-the-box AI experience, you build the one you want.
Pricing:
- Free: full base app, all community plugins.
- Sync: $8/month for first-party sync (optional).
- AI: cost is whatever your chosen API charges per token, typically a few dollars per month for personal use.
Platforms: Android, iOS, Mac, Windows, Linux.
Bottom line: Pick Obsidian when you want your AI to read your vault without sending it to anyone else’s server.
5. Mem, best AI-native auto-organizing notes
Mem is the AI note app that picks up where the others stop tagging. Write a quick note in the Android app, and Mem auto-tags it, links it to related notes you wrote months ago, and surfaces relevant context the next time you open a similar note. There are no folders by design. The thesis is that the AI does the filing so you do not have to.
Mem Chat lets you ask questions across your entire note graph, which is the cross-vault Q&A that Notion AI and Obsidian only do with extra setup. The app feels closer to a journal with infinite memory than a structured workspace, which suits people whose notes are scattered fragments rather than long-form pages.
Where it falls short: No offline mode of substance, everything is cloud-first. The free trial is short and the paid plan starts at $14.99 per month per user, which puts it above mainstream rivals. Auto-organization is also opinionated, you cannot easily override how the model decides things relate.
Pricing:
- Free trial: limited, 7 to 14 days depending on the cohort.
- Standard: $14.99/month for unlimited notes, AI features, and Mem Chat.
Platforms: Android, iOS, web, Mac.
Bottom line: Pick Mem if you write fragments all day and want the AI to do the filing instead of building a folder hierarchy.
6. Reflect, best fast AI notes with daily journaling
Reflect is the AI note-taking app for journalers and quick capturers. The Android app opens to a daily note in under a second, supports voice-to-text with on-device transcription, and GPT-class AI is one keystroke away to summarize, expand, or query past entries. Backlinks work the same way Roam and Obsidian use them, every [[term]] becomes a node in the graph.
Where Reflect stands out is the speed and the journaling angle. The base unit is the day, not the project, and the AI is tuned to surface relevant past notes when you start writing about a recurring theme. For people whose thinking happens in journal entries rather than research projects, this lands closer to the workflow than the database-first tools.
Where it falls short: The pricing tier is $15 per month with no real free option beyond the trial, which is steep for what is essentially a journaling app. Limited file uploads, no support for long PDFs in the same way NotebookLM or Claude handle them.
Pricing:
- Free: 7-day trial.
- Standard: $15/month or $120/year, all AI features included.
Platforms: Android, iOS, Mac, Windows, web.
Bottom line: Pick Reflect if you journal every day and want a single shortcut to query, summarize, or expand a past entry.
7. Evernote, best for legacy capture with an AI layer
Evernote is on this list because the AI features added in 2024 and refined through 2026 are genuinely useful, and the underlying capture engine still beats most competitors. Web Clipper, document scanning, OCR on images, and audio recording in one app, with AI Edit and AI Search now sitting on top to summarize, rewrite, and answer questions across the whole notebook collection. For users sitting on a decade-old Evernote vault, this is the cheapest way to make those notes searchable in a useful way.
The AI features became Personal-tier or higher in 2024, so the free plan covers basic notes only. Where Evernote earns its place over the newer AI-native tools is the long history and the data portability, you can export the whole thing to HTML or ENEX whenever you want to leave.
Where it falls short: The brand has been through three ownership changes, and the UI still carries the visual baggage of those eras. Mobile performance on very large notebooks is noticeably slower than newer apps. The free plan’s 50-note ceiling makes it useless for new users, treat the Personal plan as the real entry point.
Pricing:
- Free: 50 notes, no AI features.
- Personal: $14.99/month with AI Edit, AI Search, unlimited notes.
- Professional: $17.99/month adds team sharing.
Platforms: Android, iOS, Mac, Windows, web.
Bottom line: Pick Evernote if you already have years of notes locked inside it and you would rather pay for AI on top than migrate everything.
How to pick the right one
- You want the cheapest mainstream pick that works: OneNote, free with capable Copilot once you have any Microsoft 365 subscription.
- You are a researcher reading PDFs and papers: NotebookLM, no other tool grounds answers in your sources as strictly.
- Your notes are databases of meetings, projects, and tasks: Notion with the AI add-on.
- You refuse to send your notes to a third party: Obsidian with Smart Connections and a bring-your-own-key model.
- You write fragments and want the AI to file them: Mem.
- You journal every day and want fast AI on your daily page: Reflect.
- You have a decade of notes in Evernote already: Stay there and turn on AI Edit.
If you find the AI features feel like a chat box stapled to a notes app, you are using the wrong tool. The picks above all do something the non-AI version of themselves cannot, which is the bar this category needs to clear.
FAQ
What is the best free AI note-taking app for Android?
Microsoft OneNote is the strongest free pick once you account for any existing Microsoft 365 subscription, which already bundles Copilot. Without 365, NotebookLM’s free tier handles document Q&A on up to 50 sources per notebook with no cost. Obsidian is free at the app level, but the AI plugins charge per token through whichever model you point them at.
Is Notion AI worth paying for?
If you already pay for Notion Plus and your notes live in databases, the $10 per month Notion AI add-on pays off quickly. The Q&A across the whole workspace and the database-aware drafting are features no other tool on this list does in the same shape. For solo users with simple page-based notes, it is harder to justify the cost.
Does NotebookLM work fully on Android in 2026?
The Android app reached feature parity with the web client for the core workflow in late 2025, including Audio Overviews, source uploads from your phone, and the Studio panel. A few features still launch on the web first by a few weeks, and the Pro tier’s notebook caps are higher than the free tier’s.
Can I use AI on my Obsidian vault without sending notes to OpenAI?
Yes. Smart Connections runs embeddings on-device or against a local Ollama server, and the Copilot for Obsidian plugin supports local models via Ollama, LM Studio, or LocalAI. Setup takes an evening, after which the AI runs entirely on your hardware.
What AI note app is best for meeting transcripts?
OneNote with Copilot handles meeting transcripts well if you record into the app or paste a transcript, especially for action item extraction. NotebookLM is better for longer recordings where you want a structured summary and grounded follow-up questions. Mem and Reflect handle short voice memos cleanly but are not built for hour-long meeting transcripts.
Are my notes used to train the model?
Most paid plans on this list opt you out by default, but the specifics vary. NotebookLM does not train on user data. Notion AI and OneNote Copilot for business plans contractually exclude training. Free tiers and consumer plans on some apps include data use clauses you should read before uploading sensitive material. Obsidian with a local model is the only setup where the question does not apply.
