Best Payment Processors · alternatives

Best Stax (by Fattmerchant) alternatives (2026)

7 alternatives to Stax (by Fattmerchant) in payment processors, ranked by entry price. Stax (by Fattmerchant) starts at $99/mo. Every figure links to the vendor's own page and the date we captured it.

Key takeaways

  • Cheaper than Stax (by Fattmerchant): Authorize.net.
  • Free alternatives: Square.
  • Closest by price: Authorize.net ($25/mo), Adyen (—/mo), Braintree (a PayPal service) (—/mo).

Stax (by Fattmerchant) alternatives compared

Ranked by entry price (lowest published self-serve monthly plan). Sourced per row.
#AlternativeEntry priceFreeHIPAABest forSource
1 Authorize.net $25/mo No No Established SMBs wanting a gateway-only solution with their own merchant account authorize.net
2 Adyen No No Large enterprise and global retailers needing unified commerce quote-only
3 Braintree (a PayPal service) No No Enterprise merchants wanting PayPal/Venmo alongside cards in one integration quote-only
4 Helcim No No Small and mid-size businesses wanting transparent interchange-plus pricing quote-only
5 PayPal No No Consumer-facing e-commerce leveraging PayPal buyer trust quote-only
6 Square Yes Yes Small and mid-size retail, food & beverage, and service businesses quote-only
7 Stripe No No SaaS and subscription businesses quote-only

Data current through 2026-06-13. Compare any two directly on the Payment Processors index.