FOSSBilling vs Kill Bill
FOSSBilling
fossbilling.orgKill Bill
killbill.ioSide by side
| Figure | FOSSBilling | Kill Bill |
|---|---|---|
| Price from | Free | $9,999/mo |
| Free plan | Yes | Yes |
| Free trial | — | Yes |
| Open source | Yes | Yes |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 2 | 5 |
| Spec score · Subscription Billing Software | 8.6 (#12) | 9.1 (#3) |
| License | The GitHub license file releases the application under Apache License 2.0 and notes inherited BoxBilling code. | The core Kill Bill project is released under the Apache 2.0 license. |
| Payment integrations | Listed payment adapters include PayPal, Stripe, Mollie, Razorpay, and others; the page cautions users to test adapters before production use. | Official materials list plugins or integrations for Stripe, Braintree, Adyen and PayPal, among others. |
| SDKs | The API documentation provides example requests for cURL, Python, and Node.js rather than publishing a separate official SDK package. | Client libraries are provided for Java, Ruby, Python, Go, PHP and JavaScript; additional community libraries include .NET. |
| Security | Documented protections include HTTPS enforcement, session fingerprinting, CSRF protection, rate limiting, IP blocking, CAPTCHA, and activity logs. | The overview describes encryption at rest and in transit, TLS communications, AES-256 stored-data encryption, audit logs, role-based access controls, and multi-tenant isolation. |
| Security controls | Security features include HTTPS enforcement, secure cookies, CSRF protection, rate limiting, session controls, IP restrictions, and role-based permissions. | The API supports authenticated requests, configurable authentication backends, granular roles and permissions, and tenant API secrets stored hashed with salt. |
| Self-hosting | FOSSBilling is self-hosted, so the operator keeps the data and controls infrastructure, backups, and security policies. | Kill Bill runs on premises, in a private data center or in a customer's cloud account, with billing data kept in the customer's database. |
| Support | The project points users to its documentation, community Discord, and email address for assistance. | The self-hosted open-source option includes community support, while paid support tiers are separately purchased for customer-managed deployments. |
| What it does | FOSSBilling is a billing and client-management system for hosting providers and digital-service businesses. | Kill Bill is an open-source platform for subscription billing, usage billing, invoicing and payments. |
Plans
Kill Bill
- Kill Bill open sourceFree
- Self-Hosted Open SourceFree
- Aviate$9,999 a month
- AWS MarketplacePrice not published
- Hosted Platform (ChaChing)Priced on request
In their own words
FOSSBilling
FOSSBilling is free, open-source billing and client-management software for hosting and other online service businesses. It can issue invoices automatically, send payment reminders, handle recurring or one-time pricing, support multiple currencies and apply promo codes. Hosting products can create and manage accounts through cPanel/WHM, DirectAdmin, HestiaCP, CWP and Plesk. Domain functions cover registration, renewal, transfers and WHOIS checks through registrar integrations, though domain prices are entered manually rather than retrieved live. A REST API provides admin, authenticated-client and public guest endpoints. Documented protections include HTTPS enforcement, session fingerprinting, CSRF protection, rate limiting, IP blocking, CAPTCHA and activity logs. It is self-hosted, requiring PHP 8.3, 8.4 or 8.5 and a MySQL-compatible database, with Apache, LiteSpeed/OpenLiteSpeed or NGINX. The project is beta, under active development, and notes rough edges and limited support.
Kill Bill
Kill Bill is an open-source, programmable billing platform with APIs for pricing models, subscriptions, invoices, and payment gateway integrations. It supports usage-based billing, and plugins connect its payment platform to gateways, issuing banks, and fraud tools. The web-based Kaui back-office interface lets teams configure price books and manage subscriptions and payments. Listed integrations include Stripe, Adyen, PayPal, Braintree, GoCardless, Coinbase, Avalara, and Vertex. Installation options include Docker and Tomcat; Kill Bill can run on Windows, Mac, or Linux computers, or on a Linux cloud server. Described security controls include encryption at rest and in transit, TLS communications, AES-256 stored-data encryption, audit logs, role-based access, and multi-tenant isolation. The self-hosted open-source option includes community support, but customers operate and upgrade it; paid support tiers are purchased separately for customer-managed deployments. The AWS Marketplace option is listed at ~$40/mo, plus AWS infrastructure costs. Hosted-platform pricing follows a separate commercial model. The maker describes the product as serving online businesses, customization-focused teams, startups, and growth-stage companies.