Stripe is the revenue engine of the modern internet economy. What started as a two-line integration for online payments has grown into a full financial infrastructure platform processing $1.4 trillion in annual payment volume as of 2024 — up 38% year-over-year. It’s used by half of the Fortune 100, including NVIDIA, PepsiCo, and Comcast.

The company holds roughly 22.3% of the US payment processing software market, sits behind 78% of the Forbes AI 50 list, and supports over 135 currencies and 100 payment methods. More than 1,000 new companies sign up to Stripe every single day.

Stripe’s edge is its machine learning layer. Its fraud detection model — Stripe Radar — trains on economy-scale data from $1.4T in annual volume, meaning every transaction makes the next one safer. In 2024 alone, Radar prevented 20.9 million fraudulent transactions worth $917 million over just Black Friday–Cyber Monday.

Best for: SaaS companies, e-commerce, marketplaces, startups, and any business with an engineering team that wants to customize payment flows.

PayPal is the most widely recognized payment brand in the United States and globally, commanding 44% of the US payment processing market and serving more than 400 million active accounts worldwide. Its services power payments on 11.9 million websites — nearly 10x more than Stripe.

For buyers, PayPal’s trust factor is unmatched: many customers actively look for the PayPal checkout button before finalizing a purchase. For merchants, that translates into real conversion lift, particularly among older demographics and customers who are skeptical about sharing card details directly.

PayPal also owns Venmo (for peer-to-peer and social commerce), Braintree (for developers needing more customization), and Honey (now integrated for offers and rewards). For merchants needing a simple checkout that customers trust immediately — especially solo operators, service businesses, and non-profits — it remains hard to beat.

Best for: Freelancers, small businesses, non-profits, service providers, and anyone selling to consumers who prefer not to share card details directly.

Adyen is the payment platform of choice for the world’s largest companies. In the US, it powers payments for Microsoft, Uber, Spotify, McDonald’s, H&M, and eBay. Unlike many gateway providers, Adyen operates as both the gateway and the acquirer — removing the middleman and giving businesses a unified view of global sales data.

Adyen’s 2024 net revenue came in at $2.16 billion, and it supports over 250 payment methods from a single integration — credit and debit cards, digital wallets, local payment methods (iDEAL, SEPA, Boleto), and in-person POS terminals globally.

One standout feature: Adyen’s integrated data insights let enterprise merchants analyze buyer behavior, cross-channel performance, and fraud patterns from a single dashboard. Its risk management tools are data-driven, not rule-based, which means fewer false declines and better authorization rates at scale.

Best for: Mid-market to enterprise retail, hospitality, airlines, and any company processing high volumes across multiple countries and channels.

Authorize.net has been processing payments since 1996 — making it one of the oldest active payment gateways in the US. Now owned by Visa, it serves over 400,000 merchants and processes more than 1 billion transactions annually. It’s a particularly strong choice for businesses that need both online payment processing and in-person POS capability from a single trusted provider.

It natively supports all major credit cards — Visa, Mastercard, Amex, Discover — along with digital payments, eChecks, and is fully integrable with Visa Checkout and PayPal. Its longevity is evidence of genuine reliability.

Best for: Established US businesses needing a reliable gateway with a long track record, particularly brick-and-mortar stores moving online, or businesses running both in-store and e-commerce.

GoCardless takes a fundamentally different approach from the others on this list. Rather than processing card payments, it specializes in ACH Debit and bank-to-bank payments — which in the US means meaningfully lower fees, fewer failed payments, and an automated collection cycle that requires almost no manual intervention.

For businesses with recurring revenue — SaaS, subscription boxes, membership organizations, service retainers — GoCardless is often the most cost-effective option. Card payments typically run 2.5–3.5% per transaction; ACH via GoCardless runs at a fraction of that cost.

GoCardless also integrates with 350+ platforms including Sage, Salesforce, Zuora, and Xero, making bank reconciliation largely automatic. One important caveat: ACH is not an instant payment, making it unsuitable for point-of-sale or time-critical transactions.

Best for: SaaS companies, subscription businesses, B2B service firms, membership organizations, and any business collecting recurring payments from the same customers repeatedly.

TrustCommerce occupies a unique position: it’s a gateway that connects merchants to multiple payment processors simultaneously, including Chase Paymentech, Elavon, and Vantiv. Rather than locking you into one processor’s pricing or uptime, TrustCommerce acts as a flexible bridge that can route transactions intelligently.

It handles credit and debit card payments, eChecks, and ACH transfers. For subscription and membership businesses, its recurring billing module handles automated collection, while a self-service customer portal lets payers view and manage their own payment status in real time.

Best for: Healthcare organizations, nonprofits, and businesses that want processor flexibility or need to support ACH alongside card payments through a single integration.