Best Open Source CRM for 2026

Looking for a CRM you can actually shape to your needs? We reviewed and compared the top open-source CRMs in 2026 to find the most customizable, developer-friendly choices for small and mid-sized teams.

How We Chose the CRMs

We intentionally selected projects that not only publish their source code, but also encourage customization and contributions. That list is smaller than it looks—many tools use “open source” as a marketing term when they really mean “there’s a free plan”, without making code modification a realistic option.

Here are the criteria we used:

• Built for SMBs: Large enterprises often require complex features and dedicated support budgets. We focused on CRMs that make sense for small and medium businesses.
• Truly open source: Each project had to provide a public, easy-to-find source code repository. The repository had to show healthy activity: multiple contributors, regular releases, and fast security fixes.
• Solid developer documentation: We only kept projects with clear, maintained documentation for developers.
• Automation and AI-friendly: We favored CRMs with solid APIs and modular design, making it easy to connect automation tools and AI assistants, and to extend the CRM with coding agents.
• Open community and roadmap: We avoided “source available” projects where development happens privately and the repository is only updated occasionally. We looked for public issue tracking, external contributions, and visible plans.
• Quick local setup: A full-stack developer should be able to install and run the CRM locally in under 30 minutes.
• Straightforward hosting: Some modern stacks are surprisingly painful to deploy. We selected CRMs that can be hosted on a standard Linux server with a simple setup.
• English-first UI: Many CRM projects are tied to a local market and never truly go international. We only included CRMs that support English, ideally along with additional languages.
• Core CRM feature set: Each project needed to include the essential CRM building blocks: contacts, companies, deals, notes, file attachments, and import/export. We excluded overly specialized tools (e.g. only for non-profits or real estate).

Based on these requirements, we kept the following open-source CRMs for evaluation (listed by preference):

1. Twenty
2. Atomic CRM
3. Krayin
4. EspoCRM
5. OroCommerce
6. SuiteCRM
7. Odoo
8. ERPNext
9. Axelor

The sections that follow provide a detailed comparison of these open-source CRMs, covering features, developer experience, and overall scoring.

Disclaimer: We are the team behind Atomic CRM, one of the products included in this benchmark. We did our best to remain objective, but we are not neutral. We have no affiliation with the other projects listed here.

---

Twenty

Twenty focuses on the core CRM features (contacts, companies, deals, notes, tasks, workflows) but does them really well. It treats developers as first-class users. Its codebase is clean and well-documented, though relatively large compared to its feature set. Despite being young, it’s already a strong option for small to medium businesses — unfortunately, it uses a contaminating license.

---

Atomic CRM

Atomic CRM leverages popular open-source libraries to minimize the code required to build a CMS (only 15k lines of code for a complete solution). As a consequence, it’s easy to learn and easy to customize. The choice of Supabase for the backend makes it super easy to host. It’s also the only open-source CRM to offer SSO. See it as a perfect template to build your own CRM rather than a full-featured CRM that you’ll spend months to adapt to your needs.

---

Krayin

Krayin is your best bet if you’re fluent with PHP and Laravel, as it leverages these technologies to provide a solid CRM foundation. It is truly open-source and also provides advanced features (albeit behind a paywall) such as multi-tenant support. However, the user interface is clunky and slow, which can be frustrating for end-users.

---

EspoCRM

EspoCRM is a very complete CRM with a clean user interface, designed for productivity. The powerful in-app administration allows you to customize pretty much everything. If its features match your needs, it’s a great choice. However, the codebase is quite large, uses homemade backend and frontend frameworks, and the documentation is limited, so even simple code customizations can be challenging.

---

OroCommerce

OroCommerce is a B2B eCommerce platform with a CRM part. While it includes basic CRM features, the primary focus is on eCommerce. Despite using modern coding practices, the extensive and complex codebase makes customization challenging, especially for basic CRM features.

---

SuiteCRM

SuiteCRM is the successor of the popular SugarCRM, open-source until 2014. Its legacy is both a chance and a burden: it has a large user base and many features, but the codebase is old and uses outdated coding practices. It is probably not the best candidate for a simple CRM.

---

Odoo

Odoo is a behemoth CRM that covers pretty much every feature you can think of. It’s also an ERP, with modules covering finance, supply chain, point of sale, human resources, marketing, and even a website builder! The main consequence is that the codebase is huge. Most Odoo projects are carried out by specialized Odoo developers who make a career out of it. It’s a good fit for large companies that need an integrated solution but not for small businesses.

---

ERPNext

ERPNext is designed to be the central hub for all your business needs, from CRM to accounting, inventory, project management, and more. But if you’re only looking for a CRM, it’s way too complex, and the workflow is too rigid. Finally, it’s not easy to dive in and start customizing the code.

---

Axelor

Axelor is another ERP / BMP low-code platform with a CRM module. Even though it’s open-source, it’s not really designed for developers to modify the code. The codebase is enormous, and the documentation is limited. It’s a good fit for companies that need a lot of features and are ready to pay for the enterprise version.

---

Honorable mentions

The following CRMs didn’t make the cut but are worth mentioning:

• vtiger (SaaS with source available, no developer docs)
• Dolibarr (not completely English, outdated code base)
• CiviCRM (only for associations and non-profits)
• Yetiforce (source code is not available)
• SugarCRM (not open-source since 2014)
• Commercial CRMs with a free tier (Hubspot, Monday, Zoho, Salesforce, etc.)

Conclusion

None of the CRMs we tested earned a perfect score. Choosing an open-source CRM still means making trade-offs.

This benchmark also highlights how rare truly customizable CRMs are. Only a small number of projects let companies modify the code without being forced to publish their changes. And many open-source CRMs come with large, complex codebases, which makes deep customization expensive. Some also rely on uncommon stacks, which can make hiring and onboarding developers harder.

Still, the outlook is positive. The top three CRMs in this benchmark (Twenty, Atomic CRM, and Krayin) stand out as strong options for small and mid-sized teams. If you want a CRM you can shape to your workflow, these are the best places to start.