Best Free Knowledge Base Software 2026: 6 Options Compared
Best free Knowledge Base Software compared: BookStack, Docmost, Outline, XWiki and 2 more, with free-plan limits, platforms and prices from official pages checked October 22, 2026.
•3 min read•Customer Support & Help Desk
Quick comparison
| Tool | Price | Platforms | Best for | Tested |
|---|---|---|---|---|
| BookStack | Free (open-source wiki you host yourself) | Web, Self-hosted | Structured internal documentation | Docs only |
| Docmost | Free (open-source Community edition); paid from $6 per seat/month, billed annually, 10-seat minimum (Business) | Web, Self-hosted | Teams that want a modern wiki they can host | Docs only |
| Outline | Free (self-hosted Community Edition with limited features and no support); paid from $4 per user/month, billed annually, 10-user minimum (self-hosted Business) | Web, Self-hosted | Teams that value a polished editor | Docs only |
| XWiki | Free (self-hosting under the LGPL-2.1) | Web, Self-hosted | Organizations that need a flexible, extensible wiki | Docs only |
| Notion | Free (unlimited pages and blocks for individuals but limited for workspaces of 2 or more members, 5 MB per file, 10 guests, 7-day page history); paid from $10 per member/month (Plus; check the pricing page for the billing term) | Web, Windows, macOS, iOS, Android | Solo users and tiny teams | Docs only |
| Confluence | Free (Free plan for 10 users with 2 GB of file storage); paid from $5.78 per user/month (Standard, at the page's default team size) | Web | Small teams in the Atlassian ecosystem | Docs only |
Independent comparison. Paid placements are labelled separately; editorial links earn no affiliate commissions. Learn more.
Good fit if
- You want a tidy book-style structure (BookStack is the pick)
- You want a hosted wiki for a small team (Confluence is the pick)
- You write alone or in a pair (Notion is the pick)
- You want a modern editor and can host it (Docmost is the pick)
Not ideal if
- You need paid-tier features, uptime guarantees or support that these free plans leave out
Free knowledge base software ranges from a team wiki to a customer-facing help center, and picking the right one starts with who reads it. For internal documentation, BookStack, Docmost, Outline and XWiki are strong. BookStack organizes pages into books and chapters, which suits people who like fixed structure, while Docmost and Outline feel closer to a collaborative document editor. XWiki is a heavier wiki platform with a long history. Confluence and Notion are hosted and free for small teams, but Notion's free plan is limited once a workspace has two or more members, and Confluence's free plan stops at 10 users and 2 GB of storage. Self-hosted options have no seat limit, but you carry the server, backups and upgrades. One thing to check is the license. Outline's source is available under a Business Source License, which is not an OSI open-source license, and some tools keep enterprise features under a separate license. If you want a public help center that customers search, check whether the tool can publish pages publicly and show them in a clean layout. If your docs are for engineers, check Markdown import and export so you are not stuck if you change tools later.
BookStack
MIT-licensed wiki you host yourself. Organizes content into shelves, books and chapters, which keeps a large documentation set tidy. You manage the server, but there is no seat limit.
Price: Free (open-source wiki you host yourself) (BookStack pricing, checked 2026-10-22).
Platforms and license: Web, Self-hosted. MIT (open source).
Project activity: 19.1k GitHub stars · latest release v26.09.2 (Oct 20, 2026) · last commit Oct 27, 2026
Best for: Structured internal documentation.
Worth knowing: You provide the hosting; the project lists sponsor hosts but says it has not vetted them.
Docmost
AGPL-3.0 core, with enterprise features under a separate license. Self-hosted community edition is free; paid plans start at $6 a seat per month. A modern editor with real-time collaboration.
Price: Free (open-source Community edition); paid from $6 per seat/month, billed annually, 10-seat minimum (Business) (Docmost pricing, checked 2026-10-22).
Platforms and license: Web, Self-hosted. AGPL-3.0 (core; enterprise features under a separate license) (open source).
Project activity: 22.1k GitHub stars · latest release v0.97.0 (Oct 25, 2026) · last commit Oct 27, 2026
Best for: Teams that want a modern wiki they can host.
Worth knowing: Some features live in an enterprise directory under a separate Docmost Enterprise license.
Outline
Source-available under Business Source License 1.1, not OSI open source. Self-hosted Community Edition is free with limited features and no support; hosted paid starts at $4 per user a month.
Price: Free (self-hosted Community Edition with limited features and no support); paid from $4 per user/month, billed annually, 10-user minimum (self-hosted Business) (Outline pricing, checked 2026-10-22).
Platforms and license: Web, Self-hosted. Business Source License 1.1 (source-available, not OSI open source).
Best for: Teams that value a polished editor.
Worth knowing: Outline's own cloud has no free tier: $10 a month for 1 to 10 members, with a 30-day trial.
XWiki
LGPL-2.1 wiki that you self-host. A mature platform with a large feature set, but heavier to run than the lighter wikis here.
Price: Free (self-hosting under the LGPL-2.1) (XWiki pricing, checked 2026-10-22).
Platforms and license: Web, Self-hosted. LGPL-2.1 (open source).
Project activity: 1.3k GitHub stars · latest release xwiki-platform-18.9.0 (Oct 26, 2026) · last commit Oct 27, 2026
Best for: Organizations that need a flexible, extensible wiki.
Notion
Free for individuals with unlimited pages and blocks, limited for workspaces of two or more members. Paid Plus is $10 per member a month. Easy to start, but the free plan has file and collaboration limits.
Price: Free (unlimited pages and blocks for individuals but limited for workspaces of 2 or more members, 5 MB per file, 10 guests, 7-day page history); paid from $10 per member/month (Plus; check the pricing page for the billing term) (Notion pricing, checked 2026-10-22).
Platforms and license: Web, Windows, macOS, iOS, Android. Proprietary.
Best for: Solo users and tiny teams.
Compare: Notion alternatives
Confluence
Free plan for 10 users with 2 GB of file storage. Paid Standard starts at $5.78 per user a month. Fits teams already using Jira or other Atlassian tools.
Price: Free (Free plan for 10 users with 2 GB of file storage); paid from $5.78 per user/month (Standard, at the page's default team size) (Confluence pricing, checked 2026-10-22).
Platforms and license: Web. Proprietary.
Best for: Small teams in the Atlassian ecosystem.
Worth knowing: Atlassian also sells a self-managed Data Center edition on request.
Compare: Confluence alternatives
Which one to pick
- You want a tidy book-style structure: BookStack
- You want a hosted wiki for a small team: Confluence
- You write alone or in a pair: Notion
- You want a modern editor and can host it: Docmost
Limits of this review
Docs-only for BookStack, Docmost, Outline, XWiki, Notion, Confluence: we did not install or run them, so feature claims come from vendor pages. Vendor prices and free limits change; confirm on the linked pricing page before you commit.
Related guides
Sources
Kevin Fan
Kevin Fan is a SaaS founder. He runs Free Instead Of, which tracks free and open-source alternatives to paid software and checks each price and free-plan limit against the vendor's own pages.
Methodology
Based on official pricing, license and product pages checked 2026-10-22: BookStack, Docmost, Outline, XWiki, Notion, Confluence. Prices, free limits and licenses are the figures shown on those pages on those dates. No tool on this page was installed or run. No accounts were created.