Outline

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

As of 30 August 2026, Outline is free to use. A fast internal wiki with a structured document editor and strong search. Softwr lists it under Documentation. Outline is available on Web, Self-hosted, iOS, Android.

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Overview

What Outline does

Outline is a knowledge base for internal team documentation: nested documents inside collections, a block-based editor with slash commands, backlinks, comments, templates, keyboard-driven navigation and search across everything the reader is permitted to see. It can be self-hosted with Postgres, Redis and S3-compatible storage, or bought as a hosted plan from the company behind it. The licence is the fact that changes shortlists. Outline is not open source in the OSI sense. It is distributed under the Business Source Licence, which permits use and modification, including running it inside your own organisation, but withholds the right to offer Outline as a service to third parties, with each release converting to an open source licence after a stated change date. For an internal wiki this is usually irrelevant and the software is effectively free. For a hosting provider, an agency planning to run instances for clients, or a company embedding it in a product it sells, it is a blocker that a procurement review will find late if nobody reads the licence first. Teams that adopted it expecting Apache or MIT terms have been caught by this. Buyers are engineering-led companies that want a wiki people actually use, with search that returns in one keystroke and an editor that does not fight Markdown. The trade-off is operational and structural: self-hosting means running Postgres, Redis, object storage and an identity provider, because Outline has no local password authentication and requires SSO. The hosted plans remove that work but offer no choice of hosting region, so a European buyer with residency requirements is pushed back to self-hosting whether they wanted the servers or not.

What people use it for

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

Where it falls short

Concrete and checkable, so you can decide whether any of them matter to you. This is the half of a review a vendor will not write about 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.

Cross-shopped

What people choose instead of Outline

Each pairing was judged by two reviewers asking whether a buyer would genuinely weigh the two against each other. The ones that failed were deleted rather than published.

Outlinevs
Nuclino
Nuclino: If you want a hosted knowledge base without a licence review or an identity provider dependency
Outlinevs
GitBook
GitBook: If some of the content has to be published externally as product documentation
Outlinevs
MkDocs
MkDocs: If the documentation belongs in Git as Markdown rather than in a database behind an application

Pricing

What Outline costs

Taken from the vendor's own pricing page. Prices move, so check before you buy.

Self-hosted

Free

Source available under the Business Source Licence
No licence fee for use inside your own organisation
Requires Postgres, Redis and S3-compatible storage
Requires an external identity provider for login
No right to offer it as a service to third parties

Team (hosted)

On request

Charged per user per month
Hosted and maintained by the vendor
Single sign-on through Google, Slack or Microsoft
No choice of hosting region

Enterprise (hosted)

On request

SAML single sign-on and provisioning
Administrative controls and audit visibility
Negotiated terms and support
Pricing on application

Capabilities

Features

Structured collections
Documents nested inside collections with per-collection permissions and ordering
Block editor
Markdown-aware editing with slash commands, embeds, tables, code blocks and diagrams
Search
Ranked full text search across permitted documents, reachable from anywhere by keyboard
Backlinks and mentions
Automatic reverse links between documents and mentions of people
Templates
Reusable document skeletons for meeting notes, decisions and postmortems
API and webhooks
REST API and event webhooks for automation and content migration
Single sign-on
Authentication through Google, Slack, Microsoft, OIDC or SAML, with no local password option
Self-hosting
Docker deployment against Postgres, Redis and S3-compatible object storage

Answered, with sources

Questions people ask

Each answer names the page it came from, so you can check it rather than take our word for it.

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.

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.

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.

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.