Glean Alternatives: 9 Options Sorted by the Stack You Already Run

The best Glean alternative is usually the AI search that already ships with the suite your company lives in. If you run on Microsoft 365, look at Microsoft 365 Copilot first. If you run on Google Workspace, look at Gemini Enterprise. If your team really works out of Notion or Slack, their own enterprise search features may cover most of what you wanted from Glean. The standalone tools only win when you need something those suites don't do well.

Here is the short version:

• Microsoft 365 shop: Microsoft 365 Copilot, with Copilot Search across Microsoft 365 and connected non-Microsoft sources.
• Google Workspace shop: Gemini Enterprise, which Google now markets as Gemini for business.
• Your knowledge already lives in one tool: Notion AI's Enterprise Search or Slack's enterprise search.
• You care most about whether answers are correct and current: Guru, which is built around verified knowledge.
• You want to self-host or read the code: Onyx (the project formerly called Danswer).
• You're building search into your own product or portal: Elastic or Coveo.

One thing to know before you compare: Glean doesn't publish prices. Its pricing page routes you to a demo, so any number you see in a roundup is someone else's quote. That matters, because the main reason people search for Glean competitors is cost. The other reasons are a narrow stack where Glean's 250-plus connectors are overkill, or a hard requirement to keep everything on infrastructure you control.

If you want the category explained first (how these systems index, why permissions are the hard part, and what to ask vendors), read our guide to AI-driven enterprise search. This post is the shortlist.

Quick comparison

Glean vs Microsoft Copilot (Microsoft 365 companies)

This is the comparison most buyers are actually making. If your email, files, meetings and chat already sit in Microsoft 365, Copilot sees most of your company's knowledge without a separate indexing project.

The licensing is the part to get right. Microsoft's Copilot overview splits things into Copilot Chat (Basic), Microsoft 365 Copilot (Basic) and Microsoft 365 Copilot (Premium). Only Premium, the paid add-on, grounds answers in your organizational data automatically through Microsoft Graph and Work IQ. On the Basic tiers, Copilot answers from the web, and you have to upload or open the content yourself. So "we already have Copilot" often means "we have the free chat," which is not a Glean replacement.

With the add-on, Copilot Search is Microsoft's universal search across Microsoft 365 apps and connected non-Microsoft data sources, and answers respect each user's permissions. Microsoft has also renamed things recently: the Microsoft 365 Copilot app is now called Microsoft Copilot, and the chat app is now Microsoft Copilot Chat. Older comparison pages still use the old names. If you're also weighing Copilot against a general assistant, see our Claude vs Microsoft Copilot comparison.

Pick Copilot over Glean when most of your knowledge is in SharePoint, OneDrive, Outlook and Teams, and you're already paying for the add-on. Stay with Glean when a big share of your knowledge sits in non-Microsoft tools and you want one neutral layer over all of them.

Gemini Enterprise (Google Workspace companies)

Google's answer sits in Google Cloud. Its documentation describes Gemini Enterprise as "an intranet search, AI assistant, and agentic platform," and the marketing page now calls it Gemini for business. The editions are Business, Standard, Plus, Pay-as-you-go and Frontline, and the edition comparison lists different seat requirements and indexing storage for each.

The connector list is broader than people expect. Google's product page lists more than 100 integrations, including Google Workspace, Microsoft 365, Slack, Confluence, Notion, Jira, Salesforce, ServiceNow and GitHub. It says Gemini indexes selected sources where they live and follows each user's existing permissions.

Pick it over Glean when your company runs on Google Workspace and already buys from Google Cloud. Check the edition table carefully, because the Business edition is documented separately from the others and has its own help center.

Workspace-native search: Notion AI and Slack

If your knowledge mostly lives in one collaboration tool, that tool's own search may be enough.

Notion AI Enterprise Search

Notion's help center says Enterprise Search is a feature of Notion AI, available on the Business and Enterprise plans. It searches your workspace and connected apps such as Slack, Google Drive and Jira, and it cites its sources. The product page also lists GitHub, Microsoft Teams, SharePoint and OneDrive, and says Notion AI only surfaces what the user already has permission to see.

It works well when Notion is your wiki and your project tracker. It's weaker when most of your knowledge sits in systems Notion doesn't connect to. If you're weighing Notion AI against other assistants more broadly, our Notion AI alternatives post covers that.

Slack enterprise search

Slack's enterprise search lets members find content from other apps, such as Google Drive and GitHub, without leaving Slack. Search results, AI answers and Slackbot responses only include content the person has permission to see. Slack's help center lists it on the Enterprise+ subscription, and on Enterprise Grid with the legacy Slack AI add-on. If you've connected Salesforce to Slack, Salesforce becomes a data source too.

That plan requirement is the catch. On lower Slack plans you get Slack's AI features but not this cross-app search.

Knowledge-base tools: Guru

Guru solves a different problem than Glean. Glean finds what exists. Guru tries to make sure what exists is correct. It calls itself "the governed knowledge layer for enterprise AI": content gets verified, routed to an expert for review, and flagged when it goes stale, and its Knowledge Agents can now verify and unverify information themselves. Answers show up in Slack and Microsoft Teams, and the pricing page lists 100-plus integrations and MCP delivery.

Pricing is sold as a package through sales, so you'll be comparing two quotes, not two price lists.

Pick Guru when the real complaint is "search finds the old policy." Support, HR and IT teams with a lot of policy content are the usual fit. Skip it when you need one search box over dozens of tools and nobody has time to curate the content.

Open source Glean alternative: Onyx

If you need to self-host, read the code, or run in an air-gapped environment, Onyx is the main option. It used to be called Danswer, and the old danswer-ai/danswer GitHub URL now redirects to the Onyx repository.

According to its README, Onyx connects to and indexes knowledge from 50-plus applications. The Community Edition is MIT-licensed, while an Enterprise Edition adds features aimed at larger organizations. It deploys with Docker, Kubernetes, or Helm and Terraform, and there's also a hosted Onyx Cloud if you want to try it before running it yourself.

The trade-off is that you own the operations. Someone has to run the deployment, manage connector credentials, and keep permissions in sync. For a team with platform engineers, that's a fair price for control over where your data and models live. For a 40-person company with no IT team, it usually isn't.

Search infrastructure: Elastic and Coveo

These two belong on the list for a different buyer: someone building search into a product, a support portal, or a custom intranet, not someone looking for an employee assistant out of the box.

Elastic

Elastic positions Elasticsearch as a single platform for search, vectors and real-time context, with prebuilt connectors, a web crawler and ingest APIs. It runs self-managed, on Elastic Cloud, or serverless, and Elastic states that Elasticsearch and Kibana are open source under the AGPL license. You get enormous control and you do the building: relevance tuning, permissions and the user interface are your job.

Coveo

Coveo sells an AI-relevance platform across commerce, service, website and workplace search. Its products include generative answering, passage retrieval and an MCP server for connecting AI agents to enterprise data. Its workplace solution is the closest to Glean, but Coveo's strength is search embedded in customer-facing and support experiences.

Pick Elastic when you have engineers and want to own the stack. Pick Coveo when the search needs to live inside your support site or portal and you'd rather buy than build.

How to choose between them

Use these questions in order. The first "yes" usually settles it.

1. Is most of your knowledge in Microsoft 365 or Google Workspace? Start with Copilot or Gemini Enterprise, and confirm which license tier actually grounds answers in your data.
2. Does it mostly live in Notion or Slack? Check whether you're on the plan that includes cross-app search.
3. Is the complaint about wrong answers, not missing ones? Look at Guru.
4. Must it run on your own infrastructure? Onyx, or Elastic if you're building the experience yourself.
5. Is the search for customers, not employees? Coveo or Elastic.
6. None of the above, with lots of tools and a big headcount? Glean is probably still the right shape, and the job becomes negotiating the quote.

Whatever you shortlist, run a pilot on your messiest real questions, with a few users who have different permissions. That test exposes more than any feature table.

Enterprise search answers questions about your company. A different problem comes up once you have the answer: turning the useful bits into something people actually run every day. Taku is an AI-native desktop workspace for that side, where you mirror a working AI app or workflow and keep it in your own workspace. Taku is in Beta, and the Mac app is available now.

FAQ

What are the main Glean competitors?

The biggest are the suite vendors: Microsoft 365 Copilot and Google's Gemini Enterprise. Next come workspace-native search in Notion AI and Slack, knowledge-base tools like Guru, the open source Onyx, and search platforms such as Elastic and Coveo.

Is there an open source Glean alternative?

Yes. Onyx, formerly Danswer, is the best-known one. Its Community Edition is MIT-licensed and self-hostable with Docker or Kubernetes, and an Enterprise Edition adds features for larger organizations. Elastic is open source under AGPL too, but it's a search engine you build on, not a ready-made assistant.

Glean vs Microsoft Copilot: which is better?

It depends on where your knowledge lives. Copilot is the natural choice when your files, mail and meetings are in Microsoft 365 and you have the Premium add-on, because only that tier grounds answers in your organizational data automatically. Glean makes more sense when your knowledge is spread across many non-Microsoft tools.

How much does Glean cost?

Glean doesn't publish pricing. Its pricing page leads to a demo request, so treat any figure you see on third-party sites as unverified and get a quote for your own headcount and connectors.

What enterprise AI search tools work for small teams?

Small teams usually do best with search built into a tool they already pay for, such as Notion AI on the Business plan, or with Onyx if someone technical can run it. Glean, Coveo and Guru all sell through sales teams and are built with larger organizations in mind.

Does enterprise search respect document permissions?

All of the tools here say they do. Copilot scopes access to user permissions, Gemini Enterprise follows each user's existing permissions, and Notion and Slack only surface content the person can already see. Test it anyway with a restricted document during your pilot.