FOSSBilling vs Polar
FOSSBilling and Polar are both billing and subscriptions software. FOSSBilling is open source under Apache-2.0, with 1.7k GitHub stars. Polar is open source under Apache-2.0, with 10k GitHub stars.
Which to pick
- Pick FOSSBilling when
- A small web host or reseller wants a free alternative to WHMCS and accepts beta software.
- Pick Polar when
- You sell software or digital products internationally and want tax handling and billing done for you.
Side by side
Billing and client management for hosting providers and other online services, with automated invoices, payment gateways, client area and provisioning extensions.
A merchant-of-record billing platform for selling subscriptions, digital products and usage-based plans, handling payments and sales tax.
The project itself says it is beta with rough edges and limited support.
Merchant-of-record means a percentage fee on each sale, and the hosted service is the real product even though the code is open.
Usable
Production-ready
Self-hosted server
Cloud service
PHP, Twig, TypeScript and MySQL
Python, FastAPI, TypeScript and Next.js
Open source, Apache-2.0 (permissive) (both)
You can build it into a product you sell, as long as you keep its copyright notice. (both)
1.7k GitHub stars
10k GitHub stars
Established: started 4 years ago, latest release 0.8.9.
Established: started 3 years ago, latest release @polar-sh/better-auth@2.1.3.
Other comparisons
More billing and subscription management systems
Both sides were judged on 2026-11-03 from each project's README and GitHub data. License, age and popularity lines are worked out directly.