Notion AI vs Mem vs Obsidian AI: Best Note-Taking AI (2026)

I’ve been searching for the perfect AI-powered note-taking system for two years now.

I’ve used Notion since 2020. Then I tried Mem when the AI features launched. I experimented with Obsidian plus various AI plugins. Each has real strengths—and real frustrations.

If you’re trying to decide between these three, I’m going to share everything I’ve learned from actually using them. Not marketing bullet points, but honest assessments from someone who’s tried to build their second brain in each.

Let’s find out which one fits YOUR workflow.

The Contenders at a Glance

Feature	Notion AI	Mem	Obsidian + AI
Primary Strength	All-in-one workspace	Self-organizing notes	Local-first, customizable
AI Focus	Writing assistant	Surfacing connections	Plugin-based (varies)
Data Storage	Cloud (Notion servers)	Cloud (Mem servers)	Local (your device)
Pricing	$10/mo + $10/mo AI	$10/mo (includes AI)	Free + plugin costs
Learning Curve	Medium	Low	High
Offline Access	Limited	Limited	Full

Before diving deep, I should note: these tools aim at different things. Notion is a workspace platform with AI added. Mem is AI-first note-taking. Obsidian is a local-first tool that can add AI. Keep that in mind.

Notion AI: The All-in-One Powerhouse

What It Is

Notion AI integrates directly into Notion’s workspace—databases, docs, projects, and wikis all in one place. The AI assistant helps with writing, summarizing, brainstorming, and querying your workspace.

What I Love About Notion AI

1. AI Across All Content Types

Notion AI works with everything in your workspace:

Summarize meeting notes
Draft documents from scratch
Fill in database properties automatically
Brainstorm ideas with prompts
Edit and improve existing text

2. Q&A Across Your Whole Workspace

This is Notion AI’s killer feature. Ask questions like “What were the action items from our Q3 planning meeting?” and it searches your entire workspace to answer. I use this constantly.

3. Seamless Integration

The AI isn’t a separate tool—it’s embedded in the writing experience. Hit a key, give a command, and it modifies your existing content. No copy-pasting between apps.

4. Template Intelligence

Create AI-powered templates that generate content automatically. Meeting note templates that produce summaries, project briefs that fill in default sections—real efficiency gains.

What Frustrates Me About Notion AI

1. The Extra Cost

Notion already costs $8-10/month. AI is another $10/month per person. For teams, this adds up fast. Mem includes AI in its base price.

2. Search Quality Issues

The Q&A feature is impressive when it works, but sometimes misses relevant content or produces incomplete answers. It’s gotten better, but still inconsistent.

3. Not Actually Note-Taking

Notion is designed for collaboration, structured databases, and project management. It’s not optimized for quick capture of fleeting thoughts. The mobile app is notably slow for this.

4. Your Data Lives in Their Cloud

For privacy-conscious users, having all your notes on Notion’s servers might be a concern. You can export, but you’re dependent on their platform.

Best For

Teams that already use Notion for projects and docs
People who want AI assistance primarily for writing and summarizing
Users who value an all-in-one workspace over specialized note-taking
Knowledge workers with structured information needs

Mem: The Self-Organizing Brain

What It Is

Mem is designed from the ground up as an AI-native note-taking tool. Its core premise: throw everything into it, and AI will help you find connections and surface relevant information when you need it.

What I Love About Mem

1. Zero Organization Required

This is Mem’s magic. You don’t need to file notes into folders. Just dump thoughts, meeting notes, ideas—and Mem’s AI finds them when they’re relevant. It actually works.

2. Automatic Connections

Mem surfaces related notes you forgot you had. Writing about a project? It shows notes from three months ago that are relevant. This has genuinely improved my work.

3. AI-First Design

Every feature assumes AI is there. Writing continues intelligently, search understands context, and the interface is built around letting AI do the organizing.

4. Lightning-Fast Capture

The mobile app is optimized for quick capture. Opened, typed, done. Notes get processed later—you just get thoughts out of your head.

5. Smart Reminders

Mem suggests when older notes need attention based on content and timing. It actively helps you resurface important information.

What Frustrates Me About Mem

1. Limited Structure

If you WANT hierarchical organization, Mem fights you. There are Collections, but the philosophy is anti-folder. Some people’s brains don’t work this way.

2. Less Versatile Than Notion

Mem is notes. That’s it. No databases, project boards, or team wikis. If you need those, you’ll need other tools or return to Notion.

3. Cloud Only

All data on Mem’s servers. No local-first option. If Mem disappears or you lose access, export is your only protection.

4. Newer Platform

Mem is younger than Notion. The company is well-funded, but there’s more platform risk with a younger startup. Notion feels more established.

5. Connection Overload

Sometimes the AI surfaces TOO many connections, and you spend time dismissing irrelevant suggestions. Fine-tuning this is an ongoing process.

Best For

People who hate organizing but want to find things later
Quick-capture enthusiasts who write lots of short notes
Researchers and creatives who benefit from unexpected connections
Users who want AI to handle the cognitive load of organization

Obsidian + AI Plugins: The Customizable Option

What It Is

Obsidian is a local-first, markdown-based note-taking app with a massive plugin ecosystem. Various plugins add AI capabilities—there’s no single “Obsidian AI,” but rather a choose-your-own-adventure approach.

What I Love About Obsidian + AI

1. Your Data Stays Yours

Notes are markdown files on your computer. Obsidian is just a viewer—if the company disappeared tomorrow, your notes remain. This matters to me.

2. Incredible Customization

The plugin ecosystem is enormous. Want AI autocompletion? There’s a plugin. Semantic search? Plugin. Custom GPT integration? Plugin. You can build exactly the experience you want.

3. Full Offline Access

Works completely offline. Edit anywhere, sync when connected. No waiting for servers, no dependency on internet.

4. One-Time or Low Cost

Obsidian is free for personal use. Sync costs $4/month if you want their sync solution. Most AI plugins are free or have one-time costs. Long-term, this is cheapest.

5. Linking and Graphs

Obsidian’s bidirectional links and graph view for visualizing connections predates AI and remains excellent. AI plugins enhance but don’t replace this.

Popular AI Plugins

Plugin	What It Does	Cost
Smart Connections	AI-powered related notes	Free
Copilot	ChatGPT in Obsidian	Free (needs API)
Text Generator	AI writing assistance	Free (needs API)
Various Summary plugins	Summarize notes/docs	Varies

What Frustrates Me About Obsidian + AI

1. Steeper Learning Curve

You need to install plugins, configure API keys, and understand how to set things up. Not plug-and-play like Notion or Mem.

2. Fragmented AI Experience

No unified AI vision—you’re cobbling together plugins that may not work perfectly together. Quality varies by plugin.

3. API Costs

Many AI plugins require your own OpenAI API key, meaning you pay per use. This can get expensive with heavy usage.

4. Sync Complexity

If you want cloud sync plus mobile access, you need to figure out sync (Obsidian Sync, iCloud, Syncthing, etc.). More setup required.

5. Less “Smart” Organization

Unlike Mem, Obsidian doesn’t auto-organize. The AI plugins help with writing and connections, but you still need to create structure yourself.

Best For

Privacy-focused users who want local-first storage
Power users who enjoy customizing their tools
Long-term thinkers who want data longevity
Budget-conscious users willing to invest setup time
Developers and technical users comfortable with configuration

Head-to-Head Comparisons

For Quick Note Capture

Winner: Mem

Mem’s mobile app and zero-organization philosophy make it fastest for dumping thoughts. Notion is slower and more structured. Obsidian requires opening the right vault and file.

For Writing Assistance

Winner: Notion AI

Notion’s inline AI commands—continue writing, improve, expand, summarize—are polished and seamlessly integrated. Mem’s AI is good but more focused on connections. Obsidian depends on which plugins you install.

For Finding Old Notes

Winner: Mem

Mem’s automatic surfacing of relevant notes is genuinely impressive. Notion’s Q&A is good but inconsistent. Obsidian’s search is fast but requires you to know what to search for.

For Team Collaboration

Winner: Notion AI

Notion is built for teams—permissions, databases, real-time collaboration are mature. Mem has some team features but is primarily individual. Obsidian with vault sharing is possible but clunky.

For Data Privacy

Winner: Obsidian

Local files on your device = you control your data. Both Notion and Mem store your notes on their cloud servers.

For Power Users

Winner: Obsidian

If you want to customize everything, Obsidian’s plugin system is unmatched. Notion and Mem are more constrained by design.

For Beginners

Winner: Notion AI (or Mem)

Both have lower barriers to entry than Obsidian. Notion if you want structure, Mem if you want to just dump notes without organizing.

Pricing Breakdown

Notion AI

Plan	Cost	AI Included
Free	$0	No
Plus	$8/mo	No
Plus + AI	$18/mo	Yes
Business + AI	$25/mo	Yes

Mem

Plan	Cost	AI Included
Free	$0	Limited
Mem+	$10/mo	Yes
Teams	$15/mo per user	Yes

Obsidian + AI

Component	Cost
Obsidian	Free (personal)
Obsidian Sync	$4/mo (optional)
OpenAI API	~$5-20/mo (usage varies)
Plugins	Usually free

Bottom line: Mem is cheapest for full AI features. Obsidian is cheapest if you’re willing to manage API costs. Notion is most expensive but includes the full workspace. For more on this topic, see our free vs paid AI tools comparison.

My Recommendations

Choose Notion AI If…

You already use Notion for work
You need team collaboration features
You want an all-in-one workspace, not just notes
You value polished AI writing assistance
Organization and structure are important to you

Choose Mem If…

You capture lots of quick notes
You hate organizing but want to find things later
You trust AI to surface relevant connections
You work mostly solo or in a small team
You want the simplest possible workflow

Choose Obsidian + AI If…

Data ownership and privacy matter to you
You enjoy customizing your tools
You want offline access without compromise
You’re comfortable with some technical setup
You’re building a long-term knowledge system

What I Actually Use

Here’s my honest setup: I use Notion for team projects and structured work documentation. I use Obsidian for personal notes and research where I want local storage and long-term access. I tried Mem and loved the AI connections, but ultimately wanted more structure and local access.

There’s no rule that says you can only use one. Different tools serve different purposes.

FAQ: AI Note-Taking Apps

Can I migrate between these apps?

Yes, but with friction. Notion exports to Markdown/CSV. Mem exports to Markdown. Obsidian uses Markdown natively. The notes transfer; the organization and connections don’t always.

Which has the best AI?

They’re using similar underlying technology. The difference is integration and approach. Notion focuses on writing assistance. Mem focuses on automatic organization. Obsidian depends on which plugins you choose.

Is my data safe in these cloud services?

Notion and Mem both have security measures and are used by businesses. But cloud = your data on someone else’s servers. Only Obsidian gives you true local control.

Can I use multiple AI note apps together?

Yes. I know people who use Mem for quick capture and Notion for structured work. The friction is copy/pasting between them.

Which is best for research?

Mem for surfacing connections across sources. Notion for structured research databases. Obsidian for linked notes and long-term research archives. Depends on your research style.

Making Your Choice

The best AI note-taking app is the one you’ll actually use consistently.

If you’re drowning in notes and hate organizing, try Mem for a month. The self-organizing approach might be revelatory.

If you live in Notion already, adding AI is a no-brainer—the integration makes it seamless.

If you care deeply about owning your data and want maximum control, Obsidian with AI plugins is your path, even if it takes more setup.

For more AI tool comparisons, check out my best AI tools everyone should use, explore free AI tools worth using, or see our guides to AI productivity tools and the best AI writing tools.

All three are excellent. The question is which one matches how YOUR brain works. Try the free tiers, see what clicks, and commit to building your system in the one that feels right.