Open source Billing & subscriptions

Lago

98 · Healthy

Usage metering and billing engine for subscriptions, usage-based plans, credits and invoicing.

AGPL-3.0★ 11kLast commit 2 days ago

Polar

97 · Healthy

Billing platform for software products, with subscriptions, usage billing, checkout and license keys.

Free to useApache-2.0★ 10kLast commit yesterday

Autumn

90 · Healthy

Pricing and billing layer on top of Stripe that handles plans, usage limits, credits and feature access.

Free to useApache-2.0★ 2.8kLast commit yesterday

OpenMeter

88 · Healthy

Real-time usage metering for AI, API and infrastructure products, feeding usage-based billing.

Free to useApache-2.0★ 2.4kLast commit yesterday

Kill Bill

77 · Stable

Subscription billing and payments platform with product catalogs, invoicing, dunning and payment gateway plugins.

Free to useApache-2.0★ 5.8kLast commit 2 days ago

Flexprice

72 · Stable

Usage-based pricing and billing with real-time metering, credits and top-ups, and feature entitlements.

Free core, paid extrasAGPL-3.0★ 6.9kLast commit 2 days ago

Kill Bill

Subscription billing and payments platform with product catalogs, invoicing, dunning and payment gateway plugins.

GitHub killbill.io

Alternative to

Zuora Chargebee Recurly

Will it still be around?

Stable

Score 77/100

Details

Can a business use it freely?

Free to use

Apache-2.0 · open source (permissive)

Details

Flat Rate Deploy

Zuora doesn't publish prices, so this starts at a $100 a month bill, the smallest where switching saves money. Kill Bill on OpenTools costs $99 a month, setup included, so you save $1 a month, about $36 over three years. Enter your actual bill to see yours.

Monthly cost

Kill Bill on OpenTools: $99
Zuora: ~~$100~~

You save each month

$1/mo

1% less than today

Saving from month one

You save

Over 3 years: $36
In year one: $12

List price checked 9 Oct 2026 · Source · Disclaimer

Bespoke

We set up Kill Bill for you. You pay once.

Worth it once your bill is $1,300 a month or more

You pay $100 a month for Zuora. Setup is $7,200, paid once, and after that Kill Bill runs for about $696 a month (your server, about $96, plus about $600 of maintenance), so at this size it takes more than 12 months to pay back.

Worth it from: $1,300/mo billpays back within 12 months
Setup, paid once: $7,200fixed price, agreed up front
Maintenance: $150/houronly when you ask for it

What we do

Data migrationRecords, files and history moved from Zuora, with a test run before the cut-over
ConfigurationWorkflows, custom fields, roles, permissions and SSO set up for your team
IntegrationsConnected to your CRM, Slack, accounting tools and APIs
MaintenanceUpdates, fixes and admin help when you ask, at $150 an hour
Paid editionsThe vendor's paid features, enabled, with the licence at cost
ComplianceData residency, audit logs, data processing agreements, security questionnaires
TrainingAn admin walkthrough, a runbook and sessions for your team

Total spent, month by monthZuoraBespoke Kill Bill

Show as a table

Month	Zuora	Bespoke	Saved so far
Today	$0	$7,200	–
Month 3	$300	$9,288	–
Month 6	$600	$11,376	–
Month 9	$900	$13,464	–
Month 12	$1,200	$15,552	–
Month 18	$1,800	$19,728	–
Month 24	$2,400	$23,904	–
Month 30	$3,000	$28,080	–
Month 36	$3,600	$32,256	–

Servers run on your own cloud account, paid to your provider. Running cost counts about 4 hours of maintenance a month; you're billed only for hours you ask for. Migration and the other activities are quoted with the setup.

Get a fixed quote

Health score: 77/100

Stable · activity, bus factor and issue responsiveness, from GitHub

Score v2 · How it works

Activity

45% weight

100/100

Last commit 2 days ago (100/100).
208 commits in the past 12 months (100/100).
7 releases in the past 12 months (100/100).

Bus factor

30% weight

51/100

Top contributor wrote 62% of the last 100 commits (past 12 months).
7 people authored those commits.

Responsiveness

25% weight

68/100

81% of all issues are closed (245 open, 1052 closed) (85/100).
17 of 30 recent issues got a reply or were closed (57/100).

License

Free to use

Apache-2.0 · Open source (permissive)

What you need to do

Use, change, host and sell it for any purpose, commercial included, with no license to buy. Keep the copyright notice.

Apache License 2.0 · Open source (permissive). OSI-approved license with few conditions beyond keeping the copyright notice.

Detected by GitHub as Apache-2.0.

GitHub activity

Stars: 5.8k
Forks: 970
Commits, 12 mo: 208; last 2 days ago
Releases, 12 mo: 7; last 11 days ago
Contributors: 48; 7 in last 100 commits
Open issues: 245; 1.1k closed

Snapshot from 2026-10-09 · Funding: github

Top contributors

Points for pull requests merged into Kill Bill and reviews of them since 10 October 2025. Building something another user asked for earns more.

Bespoke · we set it up$7,200once Flat Rate Deploy$99/mo