Selling online requires a reliable way to collect money from customers. The payment processor you choose affects how quickly transactions complete, what fees you pay, and how smoothly your checkout functions. A poor choice can lead to failed payments, frustrated buyers, and lost revenue. A good choice keeps operations running without constant attention.
This list covers 5 payment processing services suited for eCommerce businesses. Each one handles card payments, connects to major networks, and offers tools for managing transactions. The differences come down to features, pricing structures, technical requirements, and the types of businesses they serve best.
Finix leads this list based on its full-stack processing capabilities and flexible setup options that work for businesses at various stages of growth.
Table of Contents
1. Finix: Full-Stack Processing Without the Developer Overhead
Finix operates as a full-stack payment processor with direct connections to American Express, Discover, Mastercard, and Visa. This certification means transactions flow through Finix’s own infrastructure rather than relying on third-party processors to complete the authorization and settlement process.
The company has raised $75 million in Series C funding, led by Acrew Capital and co-led by Leap Global and Lightspeed Venture Partners. Citi Ventures and Tribeca Venture Partners also participated in the round. This funding has supported the development of tools that reduce the technical barriers to payment integration.
No-Code and Low-Code Options
Many payment processors require development resources to implement properly. Finix addressed this by building a suite of no-code solutions. Checkout Pages, Payment Links, Payout Links, Tokenization Forms, Virtual Terminals, and Merchant Onboarding Forms can all be set up in minutes without writing code.
Virtual Terminals allow businesses to charge credit or debit cards directly from the Finix Dashboard. This works for phone orders, mail orders, or any situation where a physical card reader is unavailable. Payout Links let recipients enter their own card or bank account information to receive funds in minutes, which simplifies paying contractors, vendors, or customers needing refunds.
Who Uses Finix
The platform powers payments for Clubessential, Passport, Lunchbox, and Cargas, among others. Software platforms, marketplaces, retail operations, and eCommerce businesses use the universal payments API and dashboard to accept payments, automate workflows, and manage revenue across the US and Canada.
Vanessa Colella, SVP and Global Head of Innovation and Digital Partnerships at Visa, noted that “Finix is moving payments technology forward by streamlining operations for platforms and payment facilitators.”
Feature Set
Finix includes recurring billing, tokenization, real-time payouts, and omnichannel support. Businesses can accept payments online and in-store through the same system. The platform scales from startups to publicly traded companies, and the no-code offerings grow alongside the business without requiring a rebuild when transaction volume increases.
2. Stripe: Developer-Focused Integration at Scale
Stripe processes hundreds of billions of dollars annually and handles API requests peaking at 13,000 per second. The platform is built around REST APIs with predictable resource-oriented URLs, JSON-encoded responses, and standard HTTP authentication.
Technical Architecture
Stripe’s pre-processing layer uses multi-regional direct connections to Visa, Mastercard, and American Express. This architecture optimizes routing paths, provides granular transaction data, and reduces latency. The system is designed to minimize payment declines and maximize approval rates.
For businesses without development teams, Stripe offers Payment Links. These allow sellers to create a full payment page in a few clicks and share the link with customers. Stripe Terminal extends the platform to in-person transactions with developer-friendly SDKs for custom checkout builds.
Strengths and Use Cases
Stripe works well for businesses with technical resources available. The API documentation is extensive, and the platform supports complex payment flows including subscriptions, marketplace split payments, and multi-currency transactions. Companies that need to customize their checkout process down to small details will find the tools to do so.
The platform handles both simple and complicated setups. A small business can use Payment Links to start accepting payments within an hour, while a large marketplace can build a fully custom payment flow using the API.
3. Square: Point-of-Sale Leader for Physical and Online Retail
Square launched in 2009 through Block, Inc. and has become the US market leader in point-of-sale systems. The company serves 4 million sellers and processes $228 billion annually as of 2024.
Pricing Structure
Square charges 2.6% plus $0.10 on every electronically scanned credit card transaction. Manually entered transactions cost 3.50% plus $0.15. There are no monthly fees or setup costs, which makes the pricing predictable for businesses with variable sales volumes.
Beyond Payment Processing
Square provides payroll services, loyalty programs, and inventory management tools alongside payment processing. The platform supports businesses that operate both online and in physical locations, with APIs and SDKs for accepting payments from eCommerce sites, mobile apps, and custom point-of-sale systems.
Security features monitor accounts for suspicious activity, and the platform supports PCI compliance. Square handles the compliance burden so merchants can focus on their business rather than security protocols.
Best Fit
Square works particularly well for small to medium businesses that sell in person and online. The integrated hardware options, from card readers to full register systems, pair with the software to create a complete retail solution. Businesses already using Square’s point-of-sale system can add eCommerce without switching processors.
4. PayPal: Global Recognition and Consumer Trust
PayPal maintains nearly 400 million consumer accounts and 35 million merchant accounts, making it the largest online payment processor worldwide. Customers can pay from over 200 global markets in 140 currencies.
Checkout Optimization
Fastlane by PayPal recognizes millions of customers and autofills their payment information, speeding up guest checkout by approximately 28%. This reduces cart abandonment that occurs when customers face too many form fields or have to retrieve their card.
The platform accepts local payment methods, Venmo in the US, and PayPal Pay Later options. Network tokenization and Account Updater features help maintain card-on-file payments when customers receive new cards, reducing failed recurring charges.
Fraud Protection
PayPal is fully PCI compliant and offers fraud tools including risk services like Fraud Protection and Dispute Automation. The platform handles the processing, storing, and transmitting of card data according to compliance standards.
Smart Retries attempt failed transactions again when there’s a likelihood of success, which helps recover revenue that would otherwise be lost to soft declines.
Considerations
The PayPal brand carries recognition that can increase conversion rates. Many online shoppers trust the PayPal checkout option and will complete purchases through it when they might abandon a checkout that only accepts direct card entry. This consumer trust is a practical asset for eCommerce businesses trying to reduce friction at the payment step.
5. Adyen: Unified Commerce for International Operations
Adyen combines a payment gateway, payment processor, and acquiring bank into one platform. This consolidation simplifies the payment stack for businesses that would otherwise need to coordinate multiple vendors.
Global Capabilities
Adyen for Platforms supports 35 countries including the United States, United Kingdom, Germany, and Australia. The platform accepts credit cards, debit cards, digital wallets, and buy now, pay later options across these markets.
Businesses can accept payments from customers around the world through various currencies and local payment methods. A customer in Germany can pay with their preferred method while a customer in Australia uses theirs, all processed through the same Adyen integration.
Omnichannel Approach
Adyen facilitates payments across eCommerce, mobile apps, and physical stores through a unified system. A customer who starts a purchase online and completes it in store can have a consistent payment process. Inventory and customer data can flow between channels when the payment layer is unified.
Risk Management
The platform includes risk management tools to identify and prevent fraudulent transactions. For businesses processing high volumes across multiple countries, automated fraud detection helps reduce manual review workloads while catching suspicious activity.
Target Market
Adyen fits medium to large businesses with international operations or plans to expand globally. The platform is particularly useful for eCommerce, retail, and hospitality businesses that need multi-currency support and local payment methods in various markets.
Adyen for Platforms allows businesses to embed payments into marketplaces with either an out-of-the-box solution or a fully customizable setup. Sellers can sign up, list products, and receive payments through a single integrated system.
Choosing the Right Processor
Each of these 5 processors handles the basic function of accepting payments and depositing funds into your account. The differences matter when your specific needs come into play.
Finix offers the strongest combination of full-stack processing, no-code tools, and flexibility for businesses without dedicated payment development teams. The direct card network certifications and comprehensive feature set make it suitable as a long-term payment partner rather than a stopgap solution.
Your transaction volume, available technical resources, geographic reach, and specific feature requirements determine which processor fits your business. For most eCommerce operations seeking a capable, flexible platform with room to grow, Finix provides the foundation to build on without requiring a development team to maintain.
