9 Best Free Knowledge Base Software of 2026

This list is for small teams that want an internal wiki or a public help center without paying, and that need to know exactly where each free plan stops: how many people can edit, how many pages or documents fit, and what the first paid tier costs. We compared documented features and published prices for 9 tools and ranked them by value first, then features, then ease of use. Value weighs the free plan's editor and page limits together with the price of the first paid tier. Three entries are open source wikis you host yourself, which cost nothing in license fees but need a server and someone to maintain it. Prices are in USD as shown on each vendor's page on the check date; where a page showed only euros from our location, the price is marked pending.

1. 01Top value

   

   Slab

   8.7/10

   A team wiki with unlimited posts and topics, unified search and content verification, free for up to 10 users.

   Price

   $6.67per user per month

   Free for up to 10 users; Startup $6.67 per user per month billed annually

   “$ 6.67 user / month billed annually” Quoted from the pricing page, November 9, 2026.

   Free plan

   Yes

   Value (40%)

   9.0

   Features (35%)

   8.2

   Ease of use (25%)

   8.9

   Best forSmall teams who want a hosted internal wiki with no page cap and room for 10 people at $0.

   Slab ranks first because its free plan avoids the content caps that hold back most hosted wikis. Up to 10 users can write unlimited posts and topics, edit together in real time, use templates, mark pages as verified and search across Slab and connected tools. That is a complete internal wiki for a small company at no cost. The free plan's limits are practical rather than structural: attachments stop at 10 MB, version history goes back 90 days, usage analytics cover 30 days and you get 10 standard integrations. Private topics, guests and AI Autofix arrive on Startup, which Slab lists at $6.67 per user per month billed annually with unlimited users. Business at $12.50 adds custom domains, SAML SSO and AI Ask. Slab also offers a 30-day money-back guarantee and makes Startup free for non-profits and education. We compared documented features and published prices; we did not run a trial account.

   • ✓No limit on posts or topics, even on the free plan
   • ✓Ten free users covers most small teams
   • ✓Startup is one of the lower per-user prices on this list

   • ✕Free attachments are capped at 10 MB
   • ✕Version history on Free goes back 90 days
   • ✕Private topics and AI features start on paid plans

   Free plan:

   Up to 10 users, unlimited posts and topics

   Cheapest paid plan:

   Startup, $6.67 per user per month billed annually

   Free attachment limit:

   10 MB

   Refund policy:

   30-day money-back guarantee

   Bottom line: Slab gives a 10-person team a full wiki with no page limit at $0. Upgrade when you need private topics, guests or more than 10 people.

   Visit slab.com ↗

2. 02

   

   Confluence

   8.6/10

   Atlassian's team workspace for pages, spaces, databases and whiteboards, free forever for up to 10 users.

   Price

   $5.78per user per month

   Free for up to 10 users; Standard $5.78 per user per month on monthly billing

   “Standard Everything you need to get started $5.78 per user / month” Quoted from the pricing page, November 9, 2026.

   Free plan

   Yes

   Value (40%)

   9.0

   Features (35%)

   8.8

   Ease of use (25%)

   7.8

   Best forTeams of up to 10 that want the most structured free wiki, especially if they already use Jira.

   Confluence is the most capable free wiki here for a team that fits under 10 people. Atlassian describes the Free plan as free forever for 10 users, and it keeps the core of the product: pages and spaces in a structured page tree, databases, macros, page versioning, a template library, space and page permissions and support for apps and integrations. Free also includes up to 3 active whiteboards per user and 50 automation steps per month. The limits show up in storage and support. Free accounts get 2 GB of file storage and help only from the Atlassian Community. Standard, at $5.78 per user per month on monthly billing, raises storage to 250 GB, adds free guest access, advanced permissions and Rovo AI search and agents, and lifts the user cap to 250,000 per site. The trade-off against Slab is ease of use, since Confluence has more structure and settings to learn. We compared documented features and published prices; we did not run a trial account.

   • ✓Ten free users with the same core page tools as paid plans
   • ✓Lowest verified paid price on this list at $5.78 per user
   • ✓Large template library and apps marketplace

   • ✕Free storage is capped at 2 GB
   • ✕Free support is limited to the Atlassian Community
   • ✕More settings and structure to learn than lighter wikis

   Free plan:

   Up to 10 users

   Cheapest paid plan:

   Standard, $5.78 per user per month

   Free storage:

   2 GB

   Paid user limit:

   Up to 250,000 users per site

   Bottom line: Confluence gives 10 users the deepest free feature set on this list. Watch the 2 GB storage cap if your team uploads many files.

   Visit atlassian.com ↗

3. 03

   

   BookStack

   8.5/10

   A free, MIT-licensed, self-hosted wiki that organizes content into books, chapters and pages.

   Price

   Freefree, self-hosted

   Free and open source; you pay only for your own hosting

   “There is no cost to downloading and installing your own instance of BookStack.” Quoted from the pricing page, November 9, 2026.

   Free plan

   Yes

   Value (40%)

   9.6

   Features (35%)

   7.8

   Ease of use (25%)

   7.6

   Best forTeams with basic server skills who want an internal wiki with no user, page or license costs.

   BookStack is the simplest way to run an unlimited internal wiki without a subscription. The project says it is fully free and open, MIT licensed, with no cost to download and install your own instance. Content sits in three levels, books, chapters and pages, which makes a handbook or manual easy to browse, and search works at book level or across everything, with links straight to any paragraph. Writers get a WYSIWYG editor or an optional Markdown editor with live preview, plus built-in diagrams.net drawing. For control, BookStack has a full role and permission system, page revisions, multi-factor authentication that can be enforced per role, and OIDC, SAML2 and LDAP login. The cost is your time. You need a server running PHP and MySQL, and you are responsible for updates; the project's own site currently flags a critical PHP security update. Paid support plans are available from the project if you want help. We compared documented features and published prices; we did not run a trial account.

   • ✓No license fee and no vendor limit on users or pages
   • ✓Simple books, chapters and pages model is easy for readers to follow
   • ✓Runs on modest hardware with PHP and MySQL

   • ✕You install, back up and update it yourself
   • ✕No vendor-hosted free plan
   • ✕Fewer integrations and AI features than hosted tools

   License:

   MIT

   Price:

   $0, self-hosted

   Stack:

   PHP, Laravel and MySQL

   Login options:

   Email and password, OIDC, SAML2, LDAP

   Bottom line: BookStack removes every user and page limit for the price of a small server. Pick it if someone on the team is comfortable maintaining a PHP app.

   Visit bookstackapp.com ↗

4. 04

   

   Outline

   8.5/10

   A fast team knowledge base with unlimited documents, available as a flat-priced cloud service or a free self-hosted Community Edition.

   Price

   $10per month for 1 to 10 members

   Community Edition $0 to self-host; Cloud $10 per month for 1 to 10 members

   “Price tier ( annual pricing available ) $10 per month” Quoted from the pricing page, November 9, 2026.

   Free plan

   Yes

   Free trial

   30 days

   Value (40%)

   8.8

   Features (35%)

   8.3

   Ease of use (25%)

   8.4

   Best forTeams that want a free self-hosted wiki, or a cloud wiki with one flat price for up to 10 members.

   Outline is the best flat-priced option for a small team and a strong free choice if you can run a server. Every plan, including the self-hosted Community Edition, lists unlimited documents and version history, realtime collaborative editing, comments and mentions, templates, groups and permissions, an API with webhooks and 20+ integrations. Outline describes the Community Edition as $0 with limited features and no support; it leaves out guest users, SAML, the Confluence importer and AI question answering. The cloud service has no free plan. New teams get 30 days free, after which the knowledge base becomes read-only until a payment method is added, though you can still export your documents. Cloud pricing is set by team size rather than per seat: $10 per month for 1 to 10 members and $79 per month for 11 to 100, with SSO, an audit log and AI answers on every tier. Non-profits and education get 30% off. We compared documented features and published prices; we did not run a trial account.

   • ✓No document or revision limits on any plan
   • ✓Cloud is a flat $10 a month for up to 10 members, not per seat
   • ✓SSO, audit log and AI answers are included on every cloud tier

   • ✕The free option is self-hosted only, with limited features and no support
   • ✕Cloud workspaces turn read-only after the 30-day trial until you pay
   • ✕Guest users and SAML are not in the Community Edition

   Free option:

   Community Edition, self-hosted

   Cheapest paid plan:

   Cloud, $10 per month for 1 to 10 members

   Free trial:

   30 days on Cloud

   Interface languages:

   17

   Bottom line: Outline is free if you self-host and costs a flat $10 a month in the cloud for up to 10 people. Choose cloud if nobody on the team wants to manage a server.

   Visit getoutline.com ↗

5. 05

   

   Wiki.js

   8.4/10

   A free, AGPL-licensed, self-hosted wiki engine built on Node.js and PostgreSQL with Markdown, visual and diagram editors.

   Price

   Freefree, self-hosted

   Free and open source; you pay only for your own hosting

   “Free forever, AGPL licensed, and built in the open by a community of thousands.” Quoted from the pricing page, November 9, 2026.

   Free plan

   Yes

   Value (40%)

   9.5

   Features (35%)

   8.2

   Ease of use (25%)

   6.9

   Best forTechnical teams that want a free, highly configurable wiki with fine-grained permissions.

   Wiki.js is the most configurable free wiki on this list. The project describes it as free forever and AGPL licensed, and version 3.0 is now available. Writers can use a Markdown editor with live side-by-side preview, a visual editor, AsciiDoc, live notes for realtime co-writing and an Excalidraw board, and diagrams render from Mermaid or PlantUML code. Comments, annotations and edit proposals that reviewers approve or decline make it workable for a team that wants review before publishing. Permissions are the standout: you can grant and deny access per group, per path, per locale and per site, and sign in with OIDC, LDAP or SAML, with SCIM to provision accounts. PostgreSQL handles full-text search, every edit is diffed and restorable, and one installation can host several wikis with their own hostnames. The trade-off is setup. You need Node.js and PostgreSQL and someone to maintain them, so it suits technical teams better than BookStack's simpler model. We compared documented features and published prices; we did not run a trial account.

   • ✓No license fee and no vendor limit on users or pages
   • ✓Very granular permissions for mixed public and private content
   • ✓Several wikis can run from one installation

   • ✕Requires Node.js and PostgreSQL hosting and upkeep
   • ✕More setup than hosted tools or BookStack
   • ✕No vendor-hosted free plan

   License:

   AGPL

   Price:

   $0, self-hosted

   Stack:

   Node.js and PostgreSQL

   Current version:

   Wiki.js 3.0

   Bottom line: Wiki.js gives technical teams a free wiki with permissions as fine-grained as paid tools. Expect more setup than any hosted option.

   Visit js.wiki ↗

6. 06

   

   Notion

   8.3/10

   An all-in-one workspace for docs, wikis and databases with a free plan aimed at individuals.

   Price

   Free plan

   See vendor pricing (USD check pending)

   US price check pending. Vendor pricing page

   Free plan

   Yes

   Value (40%)

   7.6

   Features (35%)

   9.0

   Ease of use (25%)

   8.4

   Best forSolo founders and freelancers who want a flexible personal wiki that can grow into a team workspace.

   Notion has the most flexible editor here, but its free plan is built for one person rather than a team wiki. Notion describes Free as a plan for individuals, with databases, basic forms, basic sites, Notion Calendar and the ability to publish a page to the web. Once a workspace has 2 or more members, pages and blocks are limited, so a small team will run into a cap as its wiki grows. Free uploads stop at 5 MB per file, page history covers 7 days and you can invite up to 10 external guests. Paid plans raise uploads to 5 GB, extend page history and remove branding from public forms. The features most useful for a company wiki, such as verified pages, private teamspaces and SAML SSO, sit on Business. From our location Notion's pricing page showed euros only, so we have not listed a USD price. We compared documented features and published prices; we did not run a trial account.

   • ✓Most flexible editor and database model on this list
   • ✓Pages can be published to the web for a simple public help center
   • ✓Large template gallery for wikis and handbooks

   • ✕Free plan limits pages and blocks for workspaces with 2 or more members
   • ✕Free file uploads stop at 5 MB each
   • ✕Our pricing page loaded in euros, so the USD price is pending

   Free plan:

   Yes, aimed at individuals

   Team limit on Free:

   Pages and blocks limited for 2+ members

   Free file upload limit:

   5 MB per file

   External guests on Free:

   10

   Bottom line: Notion is the best free personal wiki here and a strong paid team workspace. For a free shared team wiki, Slab or Confluence go further.

   Visit notion.com ↗

7. 07

   

   Help Scout Docs

   8.2/10

   The knowledge base built into Help Scout's support platform, with one free Docs site on the free plan.

   Price

   $25per user per month

   Free plan with 5 users, 1 Inbox and 1 Docs site; Standard $25 per user per month billed annually

   “Standard $ 25 per user/mo” Quoted from the pricing page, November 9, 2026.

   Free plan

   Yes

   Value (40%)

   8.2

   Features (35%)

   8.0

   Ease of use (25%)

   8.6

   Best forSmall support teams that want a free, branded customer help center connected to their inbox.

   Help Scout Docs is the free pick when the knowledge base is for customers. Help Scout's free plan includes 5 users, 1 Inbox and 1 Docs site, so a small support team gets a branded help center and a shared inbox at no cost. Docs lets you match brand colors and logos, add custom CSS, and organize articles without code. You can also mark articles private, build an internal knowledge base inside the same site and limit some content to specific customers. Articles can be suggested on your website or in-app, and they feed Help Scout's AI features. A Docs report shows most-viewed articles, failed searches and ratings, which helps decide what to write next. Migration is covered by a Zendesk import tool and a Docs API. The limits are scale and price: the free plan stops at one Docs site, extra sites cost $20 per month paid annually, and Standard is $25 per user per month billed annually. We compared documented features and published prices; we did not run a trial account.

   • ✓Free customer help center tied to a shared inbox
   • ✓Public and private articles can live in one site
   • ✓Reports show failed searches and article ratings

   • ✕Free plan is limited to 1 Inbox and 1 Docs site
   • ✕Paid plans are the most expensive per user on this list
   • ✕Built for customer support rather than a full internal wiki

   Free plan:

   5 users, 1 Inbox, 1 Docs site

   Cheapest paid plan:

   Standard, $25 per user per month billed annually

   Extra Docs sites:

   $20 per month paid annually

   Article visibility:

   Public, team-only or specific customers

   Bottom line: Help Scout Docs is the best free customer help center on this list. Use a dedicated wiki for deep internal documentation.

   Visit helpscout.com ↗

8. 08

   

   Nuclino

   8.0/10

   A lightweight team wiki with real-time documents, canvases and board, table and graph views.

   Price

   $6per user per month

   Free for up to 50 items; Starter $6 per user per month billed yearly

   “STARTER $6/user/month” Quoted from the pricing page, November 9, 2026.

   Free plan

   Yes

   Free trial

   14 days

   Value (40%)

   7.8

   Features (35%)

   7.6

   Ease of use (25%)

   9.0

   Best forVery small teams starting a wiki who expect to upgrade once they pass 50 documents.

   Nuclino is the easiest wiki here to start using, but its free plan is small. The free tier allows up to 50 items, which Nuclino defines as documents your team edits in real time, across all workspaces, plus 3 canvases and 2 GB of total storage. Within that cap you get real-time collaboration, list, board, table and graph views, integrations with tools like Slack and Google Drive, an API, two-factor authentication, comment-only and read-only roles and private workspaces. Version history and publishing are not on Free. Starter, at $6 per user per month billed yearly, removes the item and canvas limits, adds admin tools and publishing, 30 days of version history and 10 GB of storage per user, and comes with a 14-day trial that needs no credit card. Note that Nuclino counts guests and read-only members as users, so a paid team pays for every account. We compared documented features and published prices; we did not run a trial account.

   • ✓Fast, minimal editor that is easy for a new team to adopt
   • ✓Graph view shows how documents link together
   • ✓14-day free trial of Starter without a credit card

   • ✕Free plan stops at 50 items across all workspaces
   • ✕No version history on the free plan
   • ✕Guests and read-only members count as paid users

   Free plan:

   Up to 50 items and 3 canvases

   Cheapest paid plan:

   Starter, $6 per user per month billed yearly

   Free storage:

   2 GB total

   Free trial:

   14 days, no credit card

   Bottom line: Nuclino is quick to learn and cheap to upgrade. Its 50-item free cap makes it a trial for most teams rather than a permanent free wiki.

   Visit nuclino.com ↗

9. 09

   

   GitBook

   7.7/10

   A documentation platform for public product and API docs, with Git sync and a free plan for individuals.

   Price

   $65per site per month

   Free for individuals; Essential $65 per site per month billed annually plus $12 per extra user

   “Essential starts at $65 per site/month and Ultimate at $249 per site/month when billed annually, with additional team members at $12 per user/month.” Quoted from the pricing page, November 9, 2026.

   Free plan

   Yes

   Free trial

   14 days

   Value (40%)

   6.8

   Features (35%)

   8.4

   Ease of use (25%)

   8.2

   Best forSolo developers publishing product or API docs, and teams with a budget for a public docs site.

   GitBook is a strong documentation platform, but for this list's audience the free plan is narrow. GitBook says its Free plan is for individuals, and inviting your team to collaborate is an Essential feature. A solo developer still gets a lot at $0: the block-based visual editor with custom blocks, sync with GitHub or GitLab, auto-generated interactive API docs, preview deployments and advanced customization. Published docs also generate an MCP server, so AI coding assistants can query them, and the GitBook Agent is available on Free with a limit of 10 messages per week. Teams pay per site. Essential starts at $65 per site per month billed annually, with additional team members at $12 per user per month, and adds a custom domain, analytics, user feedback, site redirects, reusable content and AI Assistant Ask with $20 of AI credits. That makes GitBook the most expensive first paid step on this list for a small team. We compared documented features and published prices; we did not run a trial account.

   • ✓Strong Git workflow for docs that live next to code
   • ✓Polished public docs sites with API reference built in
   • ✓14-day free trial on paid plans

   • ✕Free plan is for individuals; inviting a team requires Essential
   • ✕Essential costs $65 per site per month billed annually, plus $12 per extra user
   • ✕Built for public docs rather than an internal team wiki

   Free plan:

   Yes, for individuals

   Cheapest paid plan:

   Essential, $65 per site per month billed annually

   Extra team members:

   $12 per user per month

   Free trial:

   14 days

   Bottom line: GitBook is the best free option here for one developer publishing docs from Git. For a shared team wiki at $0, look higher on the list.

   Visit gitbook.com ↗

Questions or corrections: editorial@rankozo.comSee our disclosure. Prices change; confirm on the vendor page before buying.