Zammad vs FreeScout vs OTOBO — Best Open Source Ticketing Systems Compared

If you run a small business or an IT team, you will eventually need a way to track support requests — and paying $50+ per agent per month for Zendesk gets old fast. The good news is that the three best open source ticketing systems are completely free, self-hosted, and production-ready. Zammad, FreeScout and OTOBO each take a different approach to the same problem, and the right choice depends on how you work. Here is a practical, hands-on comparison to help you pick.

Zammad

Zammad is the closest thing to a drop-in Zendesk replacement. It is a web-based helpdesk built in Ruby on Rails, developed by Zammad GmbH in Berlin and licensed under AGPL-3.0. Rather than forcing every conversation through email, Zammad pulls channels together into one ticket queue: email, live chat, phone calls, and social media all land in the same interface. You can find it in our Zammad directory listing.

The standout feature is the unified inbox. Customers can reach you by chat widget, Telegram, or plain email, and your team sees everything in one place with full-text search that even indexes attachments. There is a built-in knowledge base, flexible text modules for canned replies, and a modern UI that new agents pick up quickly. Setup is well documented for Docker, Debian, Ubuntu and CentOS, with PostgreSQL and Elasticsearch doing the heavy lifting.

• Channels — email, live chat, phone/CTI, Telegram and other social channels in one ticket queue.
• Full-text search — searches tickets and attachments, fast even on large archives.
• Knowledge base — publish customer-facing articles and use them to resolve tickets faster.
• Text modules — reusable canned replies so common questions get consistent answers.
• Multilingual — the interface supports more than 40 languages.
• Mobile view — manage tickets and replies from a phone without a separate app.
• Integrations — Telegram, GitHub, GitLab, Jira, Slack and more via the Zammad app marketplace.

FreeScout

FreeScout is the lightweight option, and it is exactly what a small team with a shared mailbox needs. Built with PHP and the Laravel framework, it is a free self-hosted Zendesk and Help Scout alternative under AGPL-3.0. The entire application is lean enough to run on a cheap VPS or even shared hosting, which makes it the easiest of the three to get going. See the FreeScout directory listing for details.

FreeScout is email-first: every support address becomes a mailbox, and conversations are threaded into tickets automatically. It includes collision detection (so two agents never answer the same message unknowingly), internal notes, auto-replies, and the ability to forward, merge and move conversations. A module system adds WhatsApp, Telegram, Facebook, Slack and live chat channels, plus OAuth login for Microsoft 365 and Google Workspace. There are no artificial limits on agents, tickets or mailboxes — it is genuinely unlimited.

• Shared inbox — multiple mailboxes, unlimited agents, tickets and conversations.
• Collision detection — a warning appears when two agents open the same conversation.
• Mobile-friendly — fully responsive interface that works from any phone browser.
• Multilingual — translated into 30+ languages, with a web installer and one-click updates.
• Modules — WhatsApp, Telegram, Facebook, Slack, live chat and more in the marketplace.
• OAuth — sign in agents with Microsoft 365 or Google Workspace accounts.
• Lightweight — runs on shared hosting; no Elasticsearch or heavy services required.

OTOBO

OTOBO is the enterprise workhorse of the group. A fork of the classic OTRS system, it is written in Perl and published under GPL-3.0 by Rother OSS in Germany. Where Zammad and FreeScout focus on fast customer service, OTOBO is built around IT service management (ITSM) and ITIL best practices — with add-on packages for configuration management (CMDB), change management and service level management. Read more in the OTOBO directory listing.

That heritage shows in the workflow engine. OTOBO lets you model proper service processes with escalations, SLAs, and defined queues, which is essential for internal IT teams that need audit trails and structured change control. It still handles classic customer service through its Customer Service Management (CSM) side, with a knowledge base, FAQ and a customer-facing portal. The trade-off is that OTOBO is more complex to administer; the recommended path is the official Docker image, and version 11.0.1 is the current stable release with a three-year support window per major version.

• ITSM add-ons — CMDB, change management and service level management packages.
• Workflow engine — escalations, SLAs, queues and process templates for structured support.
• ITIL-aligned — designed around ITIL practices for enterprise IT departments.
• Customer portal — self-service where customers can track and update their own tickets.
• Knowledge base & FAQ — central documentation for agents and customers.
• Directory integration — LDAP and Active Directory support for enterprise logins.
• Open interfaces — REST API and generic interface for connecting other systems.

Head-to-Head Comparison

Pricing

• Zammad: Free community edition (AGPL-3.0), self-hosted with no per-agent fees. Paid cloud hosting exists but is optional.
• FreeScout: Free core (AGPL-3.0). Optional paid modules and paid cloud hosting; self-hosted core is unlimited.
• OTOBO: 100% open source and licence-free (GPL-3.0). Paid support, consulting and managed services available if you want them.

All three are genuinely free to run yourself. The money question only appears if you want hosted convenience or vendor support.

Setup Complexity

• FreeScout: Easiest. Web installer, runs on shared hosting, no extra services required.
• Zammad: Moderate. Docker or distro packages, but needs PostgreSQL and Elasticsearch alongside.
• OTOBO: Most involved. Docker image is recommended; ITSM modules and configuration add admin overhead.

Feature Depth

• Zammad: Broad out of the box — channels, knowledge base, search and automation in one polished package.
• FreeScout: Focused — excellent email ticketing and collaboration, with channels added via modules.
• OTOBO: Deepest for IT — ITSM, CMDB, change management and SLA workflows nothing else here matches.

Mobile Support

• FreeScout: Fully responsive, 100% mobile-friendly in the browser.
• Zammad: Dedicated mobile view for managing tickets on the go.
• OTOBO: Responsive and usable on mobile, but designed primarily for desktop-heavy ITSM work.

Integrations

• Zammad: Large app marketplace — Telegram, GitHub, GitLab, Jira, Slack and more.
• FreeScout: Channel modules (WhatsApp, Telegram, Facebook, Slack, live chat) plus OAuth for Microsoft 365 and Google Workspace.
• OTOBO: LDAP/Active Directory, REST API, and a generic interface for custom connectors.

Which One Should You Pick?

Choose Zammad if: you want an all-in-one support desk with live chat, social channels and a knowledge base, and you are happy running a slightly heavier stack. It is the best balance of features and polish for most growing teams.

Choose FreeScout if: you are a small team or a startup that mostly lives in email, and you want something up in an afternoon on a cheap server. It punches far above its weight and scales with modules when you outgrow it.

Choose OTOBO if: you run an IT department that needs proper ITSM — change management, CMDB, SLAs and audit-ready workflows. If ITIL is in your vocabulary, OTOBO is the only one of the three built for you.

The Bottom Line

For most small businesses and support teams, Zammad is the pick — it delivers the full Zendesk experience for free, with the channels and knowledge base your customers expect. FreeScout is the smart choice when simplicity and a shared mailbox are all you need, and OTOBO wins for enterprise IT teams that need ITSM-grade workflow management. Whichever you choose, you keep your data, you keep your money, and you never pay per agent again.

Download it at zammad.org, freescout.net or otobo.io — free, no subscriptions, no account required.

Looking for more self-hosted business tools? Browse our Ticketing & Customer Support category or the full free and open source directory.