What are the best open source alternatives to Glean?

The top open source alternatives to Glean include Onyx and Pipeshub. These tools offer similar functionality while being free and open source.

Why choose an open source alternative to Glean?

Open source alternatives provide transparency, community support, no vendor lock-in, and often cost savings. You can customize the software to your needs and have full control over your data.

Are these Glean alternatives really free?

Yes, all listed alternatives are open source and free to use. You may need to pay for hosting if you self-host, but the software itself is free.

2 Best Open Source Glean Alternatives in 2026

Onyx is a powerful open-source enterprise search platform that transforms how teams find and access information. With seamless integration across 40+ popular business tools like Slack, GitHub, Notion, and Google Workspace, it creates a unified search experience powered by AI.

Key features include:

AI Workplace Search that helps teams quickly find answers across all connected apps and documents
AI Assistant capabilities that leverage your organization's knowledge to provide contextual responses
Developer-friendly APIs for building custom workflows and integrations
Enterprise-grade security with document-level permissions and optional air-gapped deployment
Model flexibility allowing you to choose or self-host your preferred AI models

The platform is designed to be highly extensible with modular architecture, making it easy to customize and adapt to your specific needs while maintaining complete control over your data.

Self-hostable enterprise AI platform that unifies business data across apps, powers a knowledge graph for cited answers, and lets teams build AI agents across their stack.

PipesHub is an open-source enterprise AI platform built for teams that need accurate, explainable answers from their internal knowledge, without shipping sensitive data to a vendor's cloud. It positions itself as a self-hostable alternative to Glean, giving organizations full control over their infrastructure, models, and data.

At its core, PipesHub builds a knowledge graph across your connected apps, so queries return structured, reasoned results rather than fuzzy keyword matches. Every answer comes with pinpoint citations: page numbers, paragraph references, and direct links back to the source document. Confidence levels are surfaced explicitly, so users know when an answer is well-supported versus tentative.

Key capabilities include:

Connectors for Google Drive, Slack, Jira, Notion, GitHub, Salesforce, Gmail, Confluence, Outlook, and Teams, all syncing in real time with permissions inherited from the source app
Collections to organize documents by team or project, with role-based access control enforced end-to-end
AI agent builder with a no-code interface and SDKs for Python, Go, and TypeScript, supporting event-driven and scheduled workflows across connected tools
Model flexibility: bring API keys for OpenAI, Anthropic, Google, or Mistral, or run fully local with Ollama. No opaque per-query charges
MCP server to expose your knowledge graph to Claude, Cursor, VS Code, or your own product
Deployment options spanning cloud, VPC, on-premise, and air-gapped environments

The platform is Apache 2.0 licensed, so every line is auditable. SOC 2 Type I compliance is in place, with ISO 27001 and VAPT certifications also covered. If a user can't see a document in Drive, they can't surface it through PipesHub either, permissions aren't re-implemented, they're inherited.

Agents can be scoped per department, triggered by events, and wired to take actions like creating Jira tickets from emails, syncing notes to Confluence, or sending Slack alerts. The platform scales horizontally and handles millions of indexed documents from a single Docker deployment up to full enterprise infrastructure.