TL;DR: Capacities vs Obsidian, opposite data models. Obsidian is plain-text Markdown, free without limits personal per Obsidian pricing page (May 2026), offline-first, 2,000+ plugins, flat folder + tags for structure. Capacities is object-based: every note is a typed object (Person, Book, Idea, Place) with structured properties, $9.99/mo Pro or $7.99/mo annual per public listings (May 2026), cloud-first. Pick Obsidian for data ownership + customization; pick Capacities for structure-out-of-the-box without plugin work. Atlas ($20/mo, free tier) wins for AI-grounded synthesis with source-cited Q&A.
Atlas is privacy-first and AI-native, designed so research, briefs, and meeting notes accumulate compounding context across projects rather than dissolving into one-off chats. Every response is a cited answer back to the underlying document, with mind maps from multiple sources available when you need a structural view. Free tier covers solo use; Pro is $20/mo. Get started.
At a glance: Obsidian founded 2020 by Erica Xu + Shida Li, 2M+ users (2024). Free without limits personal per Obsidian pricing page (May 2026); Sync $4/user/mo annual ($48/yr) or $5/mo monthly, Publish $8/site/mo annual ($96/yr) or $10/mo monthly, Commercial $50/user/year, Catalyst $25 one-time. 2,000+ community plugins. Capacities founded ~2022 by Steffen Bleher, German-built, object-based PKM. Free tier; Pro $9.99/mo monthly or $7.99/mo annual per public listings (May 2026); Believer lifetime per capacities.io/pricing (May 2026). Both run on Web (Capacities) + macOS, Windows, Linux (Obsidian), iOS, Android. Obsidian: data lives locally as .md files. Capacities: data lives in the cloud, downloadable.
The Obsidian vs Capacities question is whether you want a programmable plain-text vault or a typed object graph. Obsidian gives you raw materials and asks you to build your system; Capacities gives you a pre-built system with named object types. This guide tests both and tells you which fits which workflow.
How We Tested
Tested over 4 weeks on macOS Sonoma, iPadOS 18, iOS 18, Windows 11. Obsidian free with Sync. Capacities Pro subscription. Workloads: 200-note research vault, daily-notes journal, Books + Papers + Authors typed objects, weekly-review template.
Disclosure: we make Atlas, one of the products discussed in this post. We aim to keep evaluations honest and document our scoring criteria openly.
1. Pricing
Obsidian. Free without limits for personal use per Obsidian pricing page (May 2026). Sync $4/user/month annual ($48/year) or $5/month monthly. Publish $8/site/month annual ($96/year) or $10/month monthly. Commercial $50/user/year. Catalyst $25 one-time. The free tier has no feature limits, an outlier across PKM tools per public surveys.
Capacities. Free tier with limits. Pro $9.99/month monthly or $7.99/month annual per public listings (May 2026). Believer lifetime per capacities.io/pricing (May 2026). The Believer tier is the unusual move: pay once, keep updates forever, a model only a handful of indie PKM tools ship.
Verdict. Obsidian free wins for solo users who don't need first-party sync. Capacities Pro is the cheaper "everything included" tier (sync, AI, mobile all built in). Anyone weighing Obsidian against simpler defaults should also see obsidian alternatives simpler.
2. Data Model
Obsidian. Plain-text Markdown files per Obsidian pricing page (May 2026). Structure via folders, tags, frontmatter, and links. You design the system. Mueller & Oppenheimer 2014 research framed this as the "external storage" problem, notes that get re-encoded by the writer outperform notes that sit in a database, and Markdown's friction (you choose tag names, link targets) is the kind of friction that drives encoding.
Capacities. Typed objects per capacities.io/pricing (May 2026). Every note has a type (Page, Person, Book, Idea, Place, Project, Quote, Image, Tweet, etc.) with structured properties per type. The system designs you, which removes the blank-page paralysis Obsidian users frequently cite per public reports on the Obsidian forum.
Verdict. Obsidian wins for flexibility and ownership. Capacities wins for users who want structure without thinking about it.
3. Daily Notes and Backlinks
Capacities. Daily notes are a built-in core feature. Bidirectional links and backlinks are first-class.
Obsidian. Daily notes are a default plugin. Bidirectional links and backlinks are first-class.
Verdict. Tie on the feature itself; Capacities is set up for you, Obsidian needs the plugin enabled.
4. Plugins and Extensibility
Obsidian. 2,000+ community plugins per Obsidian's plugin directory (May 2026). Dataview (query as database), Excalidraw, Templater, Smart Connections, Calendar, Mind Map. Karpicke & Roediger 2008 research on retrieval practice (80% vs 36% one-week recall) maps onto Dataview queries; "show notes touched in the last 14 days" surfaces material at exactly the spaced-repetition window the studies recommend.
Capacities. No plugin system. Built-in features only; the team ships updates. The closed system means fewer dependencies to break across upgrades, a tradeoff cited by users who left Obsidian to escape plugin churn per public reports.
Verdict. Obsidian wins decisively for power users. For a Notion-vs-Obsidian framing of the same trade-off, see Notion vs Obsidian.
5. Mobile
Capacities. Mobile apps for iOS and Android per capacities.io/pricing (May 2026). Cloud-synced; works offline once content is loaded. Cold-start is around 2-3 seconds on a 2024 iPhone per user reports.
Obsidian. Mobile apps for iOS and Android. Sync requires Obsidian Sync at $4/user/month annual ($48/year) per Obsidian pricing page (May 2026), iCloud Drive, Syncthing, or Git. A 1,000-note vault opens in 2-4 seconds on a 2024 iPhone per public benchmarks; large vaults (10K notes) push that to 6-8 seconds, which the Microsoft Work Trend Index 2024 research framed as a productivity tax across knowledge workers using 3+ devices weekly.
Verdict. Capacities wins for mobile users who want zero sync setup. For Apple-only Markdown writers comparing mobile-polished options, Bear vs Obsidian covers that axis.
6. AI Features
Capacities. AI Assistant (Pro) for summaries, rewrites, Q&A inside the app per capacities.io/pricing (May 2026).
Obsidian. Smart Connections plugin (free, BYO OpenAI key), Copilot for Obsidian plugin, local LLM via Ollama. More flexible but more setup. The Ahrefs 600K-page AI-content study reported 86.5% of top-ranked pages now use some AI assistance, so a vault with semantic-search AI is a baseline expectation in 2026, not an upgrade.
Verdict. Capacities wins out-of-box. Obsidian wins on flexibility and BYO-key cost. For an Evernote-flavored take with built-in AI Search, Obsidian vs Evernote tests that path.
7. Web Clipper
Capacities. Browser extension clips to typed objects (e.g., clip a tweet creates a Tweet object) per capacities.io/pricing (May 2026). The typed-clipper pattern means a clipped book auto-fills author, year, and ISBN where Capacities can detect them, which removes friction at capture time.
Obsidian. Official Web Clipper (2024) clips to Markdown per Obsidian pricing page (May 2026). The clipper output is a .md file in your vault, which the Microsoft Work Trend Index 2024 research framed as the kind of low-friction capture pattern knowledge workers default to.
Verdict. Capacities wins on typed-clipping workflow. Obsidian wins on Markdown ownership of clips.
8. Data Portability
Obsidian. Markdown files in a folder per Obsidian pricing page (May 2026). Open with any editor. Migrate freely. Public reports indicate that vaults from 2020 still open cleanly in 2026 builds; the Markdown-spec stability is the architectural reason.
Capacities. Markdown export with frontmatter per capacities.io/pricing (May 2026). Round-trip works for typed objects but views and queries don't transfer. A 1,000-note migration plus query rebuild in Obsidian Dataview takes a few hours per user reports.
Verdict. Obsidian wins decisively. For a smart-notes synthesis layer that sits above either tool, see smart notes app.
When to Pick Obsidian
You want plain-text data ownership. You build a long-term knowledge base and worry about tool lock-in. You want a plugin ecosystem (Dataview, Excalidraw, Smart Connections). You're fine with upfront system design. You're on Linux or want offline-first behavior.
When to Pick Capacities
You want structure without plugin tinkering. You think in typed objects (Books, People, Projects, Concepts). You want daily notes, backlinks, mobile sync, and AI Assistant all included. You're fine with cloud-first storage. You want to be productive in 30 minutes, not 30 hours.
When to Pick Atlas
Neither does AI synthesis with source citations well at scale. Atlas turns notes, PDFs, and research into a navigable mind map and answers cross-source questions with citations to the specific passage. Pair Atlas with Obsidian (reads your vault) or Capacities (export Markdown to Atlas). Free tier, $20/month Pro. Try Atlas free.
Comparison Table
| Axis | Obsidian | Capacities |
|---|---|---|
| Price | Free + $48/yr Sync (annual) | $9.99/mo or $7.99/mo annual |
| Storage | Local .md files | Cloud (downloadable) |
| Data model | Plain text, you shape | Typed objects, pre-shaped |
| Plugins | 2,000+ | None |
| Mobile sync | $48/yr annual or BYO | Built in |
| AI | BYO via plugins | Assistant included |
| Web Clipper | Markdown | Typed objects |
| Daily notes | Plugin (one click) | Built in |
| Best for | Power users, owners | Plug-and-play PKM |
Final Take
Obsidian wins for users who want plain-text plain-folder data ownership and a plugin ecosystem to extend the tool. Capacities wins for users who want a typed object graph out of the box with sync and AI included. The split is taste: shape your own system or use someone else's. For AI-grounded synthesis with source citations across either tool's content, Atlas beats both.
