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Research · head to head

Obsidian vs Outline

Obsidian logo

Obsidian

Research

A powerful knowledge base on top of a local folder of plain text Markdown files

From
Free
Rated
-
Full reviewWebsite
Outline logo

Outline

Documentation

Team knowledge base under the Business Source Licence, self-hostable or vendor hosted

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Obsidian sync is a paid add-on at $4 per month billed annually rather than part of the app; Outline the Business Source Licence is not an open source licence, so anyone planning to host Outline for clients, resell it or embed it in a commercial service is prohibited until the per-release change date passes, and this is regularly discovered only at legal review.
  • They diverge on capability: Obsidian covers Bidirectional linking, Outline covers Structured collections.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Obsidian and Outline actually diverge.

Attributes where Obsidian and Outline differ
AttributeObsidianOutline
Pricing modelUnknownFree to self-host, per user per month when hosted by the vendor
PlatformsWeb, Windows, macOS, Linux, iOS, AndroidWeb, Self-hosted, Docker, iOS, Android
CategoryResearchDocumentation
Founded2020Unknown

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Obsidian

  • Bidirectional linking
  • Graph view visualization
  • Markdown support
  • Local file storage
  • Plugin ecosystem
  • Custom CSS themes
  • Search and tags
  • Zotero

Only in Outline

  • Structured collections
  • Block editor
  • Search
  • Backlinks and mentions
  • API and webhooks
  • Single sign-on
  • Self-hosting

Both cover

  • Templates

What people use each for

The jobs each tool is most often brought in to do.

Obsidian

  • Local-first markdown note taking with no account requirednot Outline
  • Linking notes into a personal knowledge graphnot Outline
  • Syncing a vault across devices with end-to-end encryption on the paid add-onnot Outline
  • Publishing a public site from a vaultnot Outline
  • Extending the editor with community pluginsnot Outline

Outline

  • Running an internal wiki on your own infrastructure when documentation cannot leave a specific jurisdictionnot Obsidian
  • Replacing a general-purpose workspace tool with something narrower where search speed and writing flow matter mostnot Obsidian
  • Keeping engineering decision records and postmortems in templated documents that link to each other automaticallynot Obsidian
  • Giving a company already standardised on Google or Okta a wiki that inherits identity and group membership directlynot Obsidian

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Obsidian

  • Sync is a paid add-on at $4 per month billed annually rather than part of the app
  • Publishing to the web is a further $8 per month per site
  • Commercial use asks for a $50 per user per year licence, though the vendor states it is not required
  • Collaboration is limited compared with a hosted notes tool, since the vault is local files first

Outline

  • The Business Source Licence is not an open source licence, so anyone planning to host Outline for clients, resell it or embed it in a commercial service is prohibited until the per-release change date passes, and this is regularly discovered only at legal review.
  • There is no local password authentication, so self-hosting requires an identity provider to be in place first, which turns a small internal wiki into a project with a dependency on Google, Okta, Entra or a Keycloak instance somebody has to run.
  • Self-hosting needs Postgres, Redis and S3-compatible object storage together, so the operational footprint is larger than the single database most internal wikis require.
  • The hosted plans offer no customer-selectable hosting region, so buyers with data residency obligations are pushed to self-hosting even when they would have paid to avoid running servers.
  • It is built for internal knowledge rather than public documentation, with no versioned documentation sets, no static output and limited public publishing, so it will not serve as a product documentation site.
  • Because it is a single-vendor project rather than a foundation-governed one, a future licence or pricing change applies to new releases and the only defence is staying on an older version.

Pricing, plan by plan

Obsidian

Free
  • Obsidian Sync$4/month
    • Sync notes across devices
  • Obsidian Publish$8/month
    • Turn notes into a website

Outline

Free
  • Self-hostedFree
    • Source available under the Business Source Licence
    • No licence fee for use inside your own organisation
    • Requires Postgres, Redis and S3-compatible storage
  • Team (hosted)$undefined/month
    • Charged per user per month
    • Hosted and maintained by the vendor
    • Single sign-on through Google, Slack or Microsoft
  • Enterprise (hosted)$undefined/month
    • SAML single sign-on and provisioning
    • Administrative controls and audit visibility
    • Negotiated terms and support

Which should you pick?

Choose Obsidian if

  • You need bidirectional linking.
  • You want to start without paying.
  • You work on Web, Windows, macOS, Linux, iOS, Android.
  • You also want graph view visualization.
Obsidian review

Choose Outline if

  • You need structured collections.
  • You want to start without paying.
  • You work on Web, Self-hosted, Docker, iOS, Android.
  • You also want block editor.
Outline review

Questions people ask

Is Obsidian or Outline better?
Neither clearly leads. Obsidian starts at Free and Outline at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Obsidian or Outline?
Obsidian starts at Free and Outline at Free.
Does Obsidian or Outline run on more platforms?
Obsidian runs on Web, Windows, macOS, Linux, iOS, Android. Outline runs on Web, Self-hosted, Docker, iOS, Android.
Can I use Obsidian for free?
Both have a free tier, so you can try either at no cost before committing.
What is Obsidian best used for?
Obsidian is most often used for local-first markdown note taking with no account required, linking notes into a personal knowledge graph, syncing a vault across devices with end-to-end encryption on the paid add-on, publishing a public site from a vault. Of those, local-first markdown note taking with no account required and linking notes into a personal knowledge graph are not what Outline is typically brought in for.
What can Obsidian do that Outline cannot?
Obsidian covers Bidirectional linking, Graph view visualization, Markdown support, Local file storage. Outline covers Structured collections, Block editor, Search, Backlinks and mentions. Both handle Templates.

Answered from the vendors’ own pages

Obsidian: Is Obsidian free?

Yes. The core Obsidian application is 100% free for personal and commercial use with no limitations. You can use unlimited vaults and every core feature without payment.

Source
Outline: Is Outline open source?

No, not in the OSI sense. It is source available under the Business Source Licence, which permits internal use and self-hosting but not offering it as a service to others, with each release converting to an open source licence after its change date.

Obsidian: What file format does Obsidian use?

Obsidian stores every note as a plain Markdown file. Because it uses standard Markdown instead of a proprietary format, your notes remain portable and can be edited with many other Markdown editors.

Source
Outline: Can I run it for free?

Yes, for your own organisation. Self-hosting carries no licence fee, only the cost of running Postgres, Redis, object storage and an identity provider.

Obsidian: Can I collaborate with others in Obsidian?

The core application does not include built-in team collaboration features. However, Obsidian offers optional add-ons and can be used with version control systems or cloud storage for collaboration.

Source
Outline: Can I choose where the hosted version stores data?

No. The hosted plans do not offer a region choice, so residency requirements mean self-hosting.

Outline: Does it work for public product documentation?

Poorly. It has no versioned documentation sets or static site output, so it is best kept for internal knowledge.

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