A payment processor sits between your business and revenue.

Pick the wrong one, and you end up with hidden fees eating into margins, clunky integrations slowing down your development team, or checkout friction driving customers away before they complete a purchase.

Pick the right one, and transactions flow without you thinking about them.

The problem is that payment processing has become crowded. Dozens of companies now compete for your attention, each promising lower fees, better tools, and faster onboarding. Founders often default to whatever name they recognize or whatever their last company used. That approach works until it doesn’t. A platform suited for a solo e-commerce store may buckle under the weight of a scaling software business with complex payout needs.

This breakdown covers 6 payment processors worth your attention. Each has a different angle on the problem. Some prioritize speed to market. Others focus on pricing transparency or global reach. The order here reflects how well each platform addresses the full range of founder needs, from early-stage simplicity to enterprise-grade flexibility.

Finix: Best Online Payment Processor

Finix operates as a full-stack payment processor, handling both online and in-person transactions across the United States and Canada. What separates it from competitors is the degree of configurability it offers without requiring a dedicated engineering team to implement.

The platform allows businesses to start processing payments within a single day using as few as 3 API endpoints. That speed matters when you’re testing a new product line or expanding into a new market. At the same time, Finix supports thousands of possible configurations, meaning you can start simple and add complexity as your business grows.

Direct connections to American Express, Discover, Mastercard, and Visa come standard. Payouts can flow through ACH, real-time payments, Mastercard Send, and Visa Direct, all managed through a single API. This consolidation removes the need to juggle multiple integrations for different payment types.

Finix raised $75 million in Series C funding in October 2024, a signal that investors see long-term potential in the platform. The company serves everyone from startups to publicly traded multinationals, which speaks to scalability.

No-Code and Low-Code Options

Not every business has developers on staff. Finix addressed this with a suite of no-code and low-code features: Checkout Pages, Payment Links, Payout Links, Tokenization Forms, Virtual Terminals, and Merchant Onboarding Forms. According to CEO Richie Serna, these tools target the 22 million businesses operating without development resources.

Setup takes minutes rather than weeks. A founder can generate payment links and send them to customers without writing a line of code. When the business grows and technical resources become available, the API remains ready for deeper integration.

Operational Infrastructure

Payment processing involves more than moving money. Finix bundles compliance, underwriting, fraud monitoring, reporting, and dispute management into the platform. These back-office functions often get overlooked during vendor selection, then become pain points later.

The recurring billing solution handles timing, commercial agreement configurations, failure scenarios, and custom situations through dashboard tools. Support runs 24/7 for emergencies. For founders who want a payment partner rather than a payment tool, Finix provides the operational depth to justify that description.

Stripe: The Developer Standard

Stripe built its reputation on developer tools. The documentation is thorough, the APIs are well-designed, and the ecosystem of plugins and integrations is extensive. If your technical team has strong opinions about code quality, they’ll likely appreciate working with Stripe.

The platform supports payments in over 135 currencies across 46 countries. Processing fees sit at 2.9% plus $0.30 per online transaction, 2.7% plus $0.05 for in-person payments through Stripe Terminal, and 0.8% (capped at $5) for ACH Direct Debit. No monthly fees or setup fees apply.

Stripe Radar provides fraud protection using machine learning that adapts to new patterns over time. The subscription management tools handle recurring payments, automatic invoicing, and flexible billing intervals, though Stripe Billing adds a 0.7% charge on billing volume.

For businesses prioritizing international reach and technical polish, Stripe remains a strong option. The tradeoff is that customization often requires engineering time, and the platform can feel over-engineered for simpler use cases.

Square: Point-of-Sale Dominance

Square leads the United States market in point-of-sale systems, serving 4 million sellers and processing $228 billion annually as of 2024. The company operates in the United States, Australia, Canada, France, Japan, Republic of Ireland, Spain, and the United Kingdom.

Pricing runs at 2.6% plus $0.10 for card swipes and 3.5% plus $0.15 for manually-entered transactions. No monthly or setup fees. Square includes fraud protection, data security, dispute management, and PCI compliance in the base offering.

Tap to Pay on iPhone and Android allows businesses to accept payments directly on a phone without additional hardware. This feature works well for service providers, pop-up shops, or any business where a traditional terminal feels excessive.

Beyond payments, Square provides e-commerce and inventory tools, appointment scheduling, payroll processing, shift scheduling, and access to banking and business loans. The ecosystem makes sense for small businesses that want a single platform for operations. Larger businesses with complex needs may find the simplicity limiting.

Braintree: PayPal’s Backend Powerhouse

PayPal acquired Braintree in 2013, and the platform now processes over $50 billion annually and handles more than 1 billion transactions per quarter. Braintree specializes in mobile and web payment solutions for e-commerce businesses.

Transaction fees sit at 2.59% plus $0.49 per transaction for cards and wallets. The platform operates in over 45 countries and supports payments in more than 130 currencies. Payment options vary by region but include PayPal, cards, and over 10 global payment methods.

Fraud protection comes in two tiers: Basic Fraud Tools for standard prevention and Premium Fraud Management Tools for advanced detection. The PayPal integration is seamless, which matters if your customer base expects PayPal as a checkout option.

Braintree fits e-commerce businesses that want solid infrastructure without the developer-heavy approach of Stripe. The PayPal ecosystem connection adds value for consumer-facing products where PayPal brand recognition drives conversions.

Adyen: Enterprise-Grade Processing

Adyen serves mid-sized and large organizations running high transaction volumes across multiple channels. The company is roughly the same size as Stripe based on payments volume, with both processing about twice what Braintree handles.

The platform uses interchange-plus pricing, which tends to benefit businesses processing enough volume to negotiate favorable rates. Adyen supports 94 payment methods and offers no-code tools like Pay-by-Link for simpler implementations.

Machine learning powers the risk controls for fraud prevention. The omnichannel focus means businesses can run online, in-store, and mobile payments through a unified system. Reporting and analytics reflect this multi-channel approach.

Adyen makes sense for businesses that have outgrown startup-stage processors and need a platform built for scale. Smaller businesses may find the enterprise focus and pricing structure less accommodating.

Helcim: Transparent Pricing for Cost-Conscious Founders

Helcim launched in 2006 and serves businesses in the United States and Canada, with particular strength among merchants processing higher sales volumes. The platform uses interchange-plus pricing, which the industry generally regards as the most transparent model available.

As of 2024, in-person transactions average 1.93% plus $0.08, while keyed and online transactions average 2.49% plus $0.25. All tools, including invoicing and Virtual Terminal, come free. No hidden fees, no monthly fees, no termination fees, no long-term contracts, no PCI compliance fees. Volume-based discounts apply automatically as transaction volume grows.

Helcim provides free invoicing software, an online checkout system for e-commerce stores, and recurring payments functionality that collects credit card and ACH payments on schedule. The straightforward approach appeals to founders who want to understand exactly what they’re paying and why.

The tradeoff is a narrower feature set compared to platforms like Stripe or Finix. Businesses needing extensive API customization or global payment methods may find Helcim too simple. Businesses prioritizing cost control will find it refreshingly honest.

Choosing Based on Your Actual Needs

Each of these processors solves a different problem. Finix offers the broadest combination of configurability, no-code options, and operational support, making it the strongest all-around choice for founders who want flexibility without complexity.

The right choice depends on your business model, your technical resources, your growth trajectory, and your tolerance for complexity. Start by identifying which problems matter most to you right now, then evaluate which platform addresses them without creating new problems you’ll have to solve later.