Finance & Billing
Payment Processing
Payment processors, checkout APIs, and merchant payment infrastructure.
Best Payment Processing tools by public signals
These picks are computed from scored public evidence. Use the openness column in the ranking to separate OSI-approved, source-available, open-core, proprietary, and unverified-license tools.
Use Case Rankings
Ordered by ToolVitals score, health, shipping, confidence, and then adoption as a tie-breaker.
| # | Tool | Health | Shipping | Openness | Stars | Score | Status |
|---|---|---|---|---|---|---|---|
| 01 | Polar Turn your software into a business. | 93 | 93 | OSI-approved OSS | 9.9k | 95 | Active |
| 02 | Hyperswitch An open source payments switch written in Rust to make payments fast, reliable and affordable | 94 | 89 | OSI-approved OSS | 43k | 94 | Active |
| 03 | Paymenter Free and open-source webshop solution for hostings | 88 | 88 | OSI-approved OSS | 1.8k | 90 | Active |
| 04 | ePUSDT Cross-platform payment gateway for Easy Payment USDT. | 87 | 87 | OSI-approved OSS | 3.5k | 89 | Active |
| 05 | Stripe Financial infrastructure for the internet | 90 | 78 | Proprietary target | — | 87 | Active |
| 06 | BTCPay Server Accept Bitcoin payments. Free, open-source & self-hosted, Bitcoin payment processor. | 85 | 75 | OSI-approved OSS | 7.6k | 86 | Active |
| 07 | lomi. The open-source payment processing platform powering West African businesses. | 72 | 76 | OSI-approved OSS | 36 | 81 | Warning |
| 08 | Lemon Squeezy All-in-one platform for selling digital products and SaaS subscriptions. | 87 | 67 | Proprietary target | — | 80 | Active |
| 09 | SpawnPay Tool for giving AI agents real USDC wallets on Base L2. | 67 | 83 | OSI-approved OSS | 0 | 80 | Warning |
| 10 | Paddle Complete billing solution for SaaS | 83 | 62 | Proprietary target | — | 77 | Active |
| 11 | PipraPay Open-source plugin-based payment gateway platform for self-hosted payment operations and automation. | 76 | 58 | OSI-approved OSS | 180 | 75 | Active |
| 12 | Zoneless Open-source Stripe Connect alternative. ~$0.002 payout fees. Identical API to Stripe. Instant global USDC payouts. Self-hosted. | 63 | 49 | OSI-approved OSS | 306 | 68 | Warning |
| 13 | XCash Open-source self-hosted cryptocurrency payment gateway. | 56 | 63 | OSI-approved OSS | 143 | 68 | Warning |
| 14 | React Native Iap In App Purchase module for React Native that confirms OpenIAP | 60 | 37 | OSI-approved OSS | 3.2k | 61 | Warning |
| 15 | Bitcart Bitcart is a free and open-source self-hosted payment processor for BTC, LTC, BCH, XMR, ETH, TRX, USDT and more | 56 | 39 | OSI-approved OSS | 948 | 60 | Warning |
| 16 | Flowglad Open source, zero webhooks payment provider | 62 | 22 | License unknown | 1.7k | 59 | Warning |
| 17 | OwnPay The premier self-hosted, open-source payment gateway automation platform. Professional, secure, and developer-first. | 59 | 14 | OSI-approved OSS | 67 | 50 | Warning |
| 18 | SaaS Payment Platform Stripe/Xendit-inspired payment API built with Go and Next.js with auth, API keys, and gateway simulation. | 43 | 7 | License unknown | 6 | 40 | Critical |
| 19 | UniPay SDK that simplifies payment gateway integration through a unified interface. | 24 | 0 | License unknown | 7 | 31 | Critical |