Stripe is the default online payment processor for software companies and marketplaces. Excellent APIs, hosted checkout, billing for subscriptions, and fast onboarding, as long as your business fits its standard risk profile.
Pricing
2.9% + 30¢ per online card transaction, custom rates above ~$1M/mo
Best for
Square
Simple all-in-one for retail, restaurants and services
2.6% + 10¢
Helcim
Transparent interchange-plus pricing that scales down
0.40% + 25¢ over interchange
Adyen
Enterprise payments across every sales channel
Custom