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. $20/mo Pro. 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
For the deeper framework, Cognitive Load, Vendor Lock-in, and Knowledge-Graph Density, applied across eight leading second-brain apps, see our second-brain apps guide.
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). $20/month Pro. Try Atlas.
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 |
Three-Year Cost in Real Numbers
Both apps have free tiers. Real cost depends on the add-ons.
| Scenario | Obsidian | Capacities |
|---|---|---|
| Solo, free tier | $0 (free personal) | $0 (free, basic) |
| Solo with sync | $144 (Obsidian Sync, $4/mo × 36) | $432 (Believer, $12/mo × 36) |
| Solo with AI | bring own API key, ~$5-20/month | included in Believer ($432) |
| Commercial use | $1,800 (Commercial, $50/user/mo × 36) | $432 (no separate license) |
Obsidian's pricing page lists Sync at $4/month, Publish at $8/month, and Commercial at $50/user/month. Capacities' pricing page lists Pro at $7.99/month and Believer (5-year prepaid) at $399 (about $80/year). The honest cost picture: for casual personal use both are free; for commercial use Obsidian's $50/user/month is the line item that surprises companies that picked Obsidian for individual employees and then had to retroactively license it.
Privacy and Data Handling
| Property | Obsidian | Capacities |
|---|---|---|
| Encryption at rest | Local (your disk) | AES-256 (Capacities cloud) |
| Encryption in transit | n/a (offline) or TLS via Sync | TLS 1.2+ |
| End-to-end encryption | Yes (Obsidian Sync) | No (server-side encryption only) |
| Trains on your data | No (no cloud, no AI) | No (per Capacities terms) |
| Data residency | Your machine | EU (Germany, per Capacities security) |
| Open file format | Yes (Markdown) | Partial (JSON export) |
Obsidian's posture is the strictest available: by default the data never leaves your device. Obsidian Sync adds end-to-end encryption with a passphrase you hold; Obsidian's servers cannot read your notes. Capacities is cloud-first with EU data residency, which is a meaningful advantage for European users with GDPR-driven preferences. For users with the highest privacy bar (medical, legal, journalism), Obsidian without Sync is the strongest answer in this category.
Migration Between the Two
Obsidian → Capacities. Capacities imports Markdown files and tries to map folders to object types. Wikilinks usually convert to Capacities backlinks; Dataview queries do not transfer (Capacities has its own query language). A 1,000-note Obsidian vault takes 3-6 hours to clean up post-import. Most plugin-driven features (Templater, QuickAdd, custom dataviews) do not have direct equivalents in Capacities.
Capacities → Obsidian. Capacities exports JSON. Obsidian does not import JSON natively; you need a script (community templates exist on GitHub) to convert each Capacities object type into a Markdown file with frontmatter. The typed-object structure becomes Obsidian frontmatter properties. A 5,000-object Capacities database takes 8-15 hours to migrate cleanly. Per the Capacities export documentation, the JSON is complete but the import-side work is yours.
Real-World Workflows Compared
A typical Obsidian day. Open the vault. Today's daily note auto-creates from the Daily Notes plugin. Capture during meetings, link to project notes with [[wikilinks]]. Lunch: tweak a Templater snippet to add a new field to the meeting template. Afternoon: run a Dataview query to surface all open action items across the vault. End of day: commit the vault to Git for version history. The pattern is do-it-yourself and infinitely customizable.
A typical Capacities day. Open the app. Today's daily note opens with the typed-object graph in the sidebar. Capture a meeting note (typed Object: Meeting), link to a Project (typed Object: Project) with the typed-relation picker. Capacities AI summarizes the meeting on the right panel. End of day: review the dashboard of recent activity across all object types. The pattern is plug-and-play and structurally constrained.
The two apps answer different questions. Obsidian answers "what system do I want to build?" Capacities answers "what does the system want me to capture?"
When You Should Run Both
Rare in practice. Both tools want to be the canonical knowledge base, and dual-writing notes wastes time. The only realistic split: Capacities for short-term project work (its typed objects accelerate setup) and Obsidian for the long-term reference vault (its plain-Markdown longevity protects 10-year archives). A monthly transfer ritual moves completed projects from Capacities into Obsidian. Most users pick one and commit.
Plugin Ecosystem Reality
Obsidian. The community plugin store has 1,500+ plugins, covering everything from advanced dataview queries to Excalidraw-style drawing canvases to AI integrations with any LLM provider. The downside: plugin sprawl. A vault with 30 plugins takes 5-10 seconds to open and develops obscure interaction bugs. The discipline of installing only the 5-10 plugins you actually use is the difference between a fast Obsidian setup and a slow one.
Capacities. No third-party plugin ecosystem. Capacities ships features in batches; users request features through the Capacities feedback portal and the team prioritizes them. The advantage: no plugin-induced slowdowns or bugs. The disadvantage: features the team has not built do not exist. The bet is on the company's roadmap rather than on a community.
Mobile and Sync Reality
Obsidian mobile. The iOS and Android apps are full-featured: same plugins, same vault structure, same Markdown editor. The catch is sync. Without Obsidian Sync ($4/month), users wire up iCloud Drive (Apple-only), Google Drive, Dropbox, or Syncthing themselves. Each free option has failure modes (iCloud has occasional sync delays; Dropbox occasionally creates conflict-suffix files when two devices edit the same note). Obsidian Sync is the friction-free path and uses end-to-end encryption.
Capacities mobile. Cloud-native sync means no setup is required: log in on the phone and the workspace appears. The mobile app is well-designed for capture but does not expose every feature of the desktop app (some advanced object operations are desktop-only). For users whose capture moment is on the phone, Capacities is the lower-friction path.
Conflict resolution. Obsidian's third-party sync paths are the most likely place for conflicts to appear; the standard advice is to close the vault on one device before editing on another, or to use Obsidian Sync which handles conflicts gracefully. Capacities resolves conflicts server-side and rarely surfaces them to the user, with the tradeoff that you cannot always tell which version "won" if two devices edited the same field within seconds.
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.
