Here are practical payment‑gateway options for U.S. small businesses, grouped by common needs with short pros/cons and pricing notes to help you pick.

Top choices by use case

• Stripe — Best for developer‑friendly online stores, subscriptions, marketplaces (high customization, broad global payment types). Typical U.S. rates for standard businesses: ~2.9% + $0.30 online; in‑person and specialized fees vary. Good if you want full control of checkout, strong APIs, and platform features (Connect, Checkout). (nerdwallet.com)

• Square — Best for small businesses that need an easy all‑in‑one POS + online presence. Very quick setup, solid free POS software, inexpensive card readers and simple flat rates for in‑person and online payments. Good choice if most sales are in person. (nerdwallet.com)

• PayPal / Braintree — Best for buyer familiarity, marketplace checkout options, and multiple wallet options (PayPal, Venmo). PayPal is easy for non‑technical merchants; Braintree (owned by PayPal) is more developer‑oriented and supports advanced gateway features. Published merchant rates vary by product (example Braintree/PayPal standard card rates are usually in the ~2.6–2.9% + fee range; see provider pages for exact figures and region‑specific rules). (paypal.com)

• Helcim — Good if you want interchange‑plus pricing (often lower cost for many merchants), transparent fees, and no long contracts. Frequently recommended for merchants who process moderate volumes and want predictable, lower‑cost per‑transaction pricing. (forbes.com)

• Authorize.Net — Good as a traditional gateway/virtual terminal that integrates with many merchant accounts and legacy systems; useful if you need a standalone gateway, phone/recurring billing, or virtual terminal functionality. It typically charges a gateway monthly fee plus per‑transaction charges (compare all‑in‑one vs gateway‑only plans). (nerdwallet.com)

• Shopify Payments — Best if you run your store on Shopify: deep integration with Shopify’s POS and checkout (rates depend on Shopify plan; using Shopify Payments avoids the platform’s extra "third‑party gateway" fee). Good for merchants who want an integrated ecommerce + POS stack. (shopify.com)

Other notes / vertical picks

• Clover, Toast, Lightspeed — consider these when you want a POS tailored to retail or restaurants (hardware + software bundles). Clover is common for small retailers; Toast is restaurant‑focused. Compare hardware costs, monthly plan tiers, and contract terms. (nerdwallet.com)

Quick pros/cons summary (very condensed)

• Stripe: + extremely flexible; − may need dev resources. (nerdwallet.com)
• Square: + plug‑and‑play for in‑person; − less optimal for complex custom online flows. (nerdwallet.com)
• PayPal/Braintree: + buyer trust and wallets; − pricing and recent fee changes can vary by product. (paypal.com)
• Helcim: + lower interchange‑plus pricing for many sellers; − less developer ecosystem than Stripe. (forbes.com)
• Authorize.Net: + virtual terminal and gateway flexibility; − may be more costly if signed up directly vs through a processor. (nerdwallet.com)

What to check before you choose (short checklist)

• True effective cost: calculate fees using your expected monthly volume, avg ticket size, domestic vs international mix (flat vs interchange‑plus matters). (nerdwallet.com)
• In‑person vs online needs: do you need hardware and POS, or only online/API/hosted checkout? (nerdwallet.com)
• Recurring billing/subscriptions or marketplace payouts — pick Stripe/Braintree or gateways that support those flows. (nerdwallet.com)
• Fraud tools, chargeback handling, settlement times, and support responsiveness. (nerdwallet.com)
• Contracts, termination fees, and PCI scope (some providers reduce your PCI burden). (nerdwallet.com)

Next practical steps (quick)

1. Estimate monthly volume and average sale amount.
2. Run a cost comparison (per‑transaction + monthly fees + hardware + chargeback rates).
3. Try sandbox or free tiers (Stripe, Square, Braintree/PayPal, Shopify all have test options) and test checkout and refunds. (nerdwallet.com)

If you want, I can:

• build a side‑by‑side cost example for your expected monthly volume (I’ll need monthly sales and average ticket), or
• recommend 2–3 providers to trial based on whether you’re primarily in‑person, online, or a mix.

(Selected sources used: NerdWallet, Forbes Advisor, provider pages for Braintree/PayPal, Helcim reviews and Authorize.Net review.) (nerdwallet.com)