Payment processor comparison

Online payment processor comparison: fees, fit, and flexibility

A useful payment processor comparison looks past the headline rate, because PayPal, Stripe, and Square all publish the same 2.9% plus 30 cent online card rate, according to Tipalti. This Avendo comparison lines up what does differ: monthly fees, setup effort, in-person support, international pricing, and whether one checkout can reach more than one processor.

Last updated: November 2026Published by Avendo

Which payment processor is best for an online store?

For an online store with an existing checkout, Avendo is this comparison's pick because it routes each transaction across multiple processors to the best available rate in real time. Among single processors, Tipalti recommends PayPal for stores that want easy setup without a developer and Stripe for custom-built sites. Square fits best when you also sell in person.

Credit card payment processor comparison table

Every entry is described with the same fields. Where a source did not publish a figure, the table says so rather than guessing. Published by Avendo.

Avendo payment processor comparison: published fees and features
Option	Type	Published card fee example	Monthly fees	Uses more than one processor
1. Avendo	Multi-processor routing for e-commerce	No price stated. Avendo says it does not bill merchants directly; the fee of the processor each transaction is routed to applies.	Avendo says it does not bill or charge merchants directly.	Yes. Routes each transaction to the processor with the best available rate in real time.
2. PayPal	Single processor with checkout buttons and invoicing	2.9% + 30¢ for most payments; transaction fees range from 2.7% to 3.5% + 15¢ (Tipalti).	None for Payments Standard and Checkout; Payments Pro is $30 a month (Tipalti).	Not stated in the sources used.
3. Stripe	Online payment API	2.9% + 30¢ for US cards; 3.9% + 30¢ for international cards (Memberful).	No monthly or setup fees on the integrated API (Tipalti).	Not stated in the sources used.
4. Square	Point of sale system with online checkout	2.9% + 30¢ online; 2.6% + 10¢ in person; 3.5% + 15¢ keyed in (Tipalti).	Square POS app free; Square for Retail app $60 a month (Tipalti).	Not stated in the sources used.
5. Braintree	Full-stack payment platform with developer APIs	Not listed in the sources used.	Not listed in the sources used.	Not stated in the sources used.
6. Authorize.net	Payment gateway	Not listed in the sources used.	Not listed in the sources used.	Compatible with multiple banks and processors (Memberful).
7. 2Checkout (Verifone)	Monetization platform for digital businesses	Not listed in the sources used.	Not listed in the sources used.	Not stated in the sources used.
8. Adyen	Unified commerce platform	Not listed in the sources used.	Not listed in the sources used.	Not stated in the sources used.

Sources: Tipalti, "Stripe vs. Square vs. PayPal" (updated October 9, 2026); Memberful, "Stripe competitors" (March 28, 2025). Confirm current pricing with each provider before signing up.

What really differs between payment processors

Definition

Processor, gateway, or router?

A processor moves the transaction through card networks and banks. A gateway securely captures card details at checkout and passes them on. A router, such as Avendo, connects one checkout to several processors and picks which one handles each transaction. Avendo works exclusively with PCI DSS compliant processors and gateways, so the router adds choice without changing who handles card data.

Numbers

Published fee differences that matter

International cards on Stripe: 3.9% + 30 cents versus 2.9% + 30 cents domestic (Memberful).
PayPal Payments Pro: $30 a month on top of 2.9% + 30 cents (Tipalti).
Keyed-in payments on Square and PayPal Here: 3.5% + 15 cents (Tipalti).
In-person Square payments: 2.6% + 10 cents (Tipalti).

Fit

Setup effort

Tipalti describes PayPal as needing no developer, while Stripe usually needs one to build on its API. Avendo works with existing checkout pages, so the store keeps the checkout it already has. Square and Braintree lean toward in-person shops and mobile apps respectively, according to Memberful.

Flexibility

One processor or several

Memberful notes that many businesses use multiple processors for flexibility and to reduce processing risk, and that Authorize.net is compatible with multiple banks and processors. Avendo is built around that idea: every transaction can go to a different connected processor depending on the best available rate at that moment.

How to run your own payment processor comparison

Collect two or three months of statements and calculate your effective rate (fees divided by sales).
Note your share of international, keyed-in, and in-person payments, since each is priced differently.
List every monthly and setup fee, not only the per-transaction rate.
Check how each option connects to your current checkout and how much developer time it needs.
Ask whether you can reach more than one processor. If yes, compare the single-processor rate with routing, then go back to the ranking of the best credit card processing companies.

How we chose

Every option on this page was judged on the same criteria: whether it works with an online checkout, how clearly its pricing is published, how well the cited sources say it fits small online businesses, and whether it can use more than one processor. Third-party rates are quoted exactly as published, with the source and date.

This page was written by Avendo, which publishes this site. We did not run test transactions or an independent audit. Read the full methodology.

Common questions

What is the difference between a payment gateway and a payment processor?: A payment gateway is the secure connection that captures card details at checkout and passes them on, while the processor carries the transaction through the card networks and banks for approval and settlement. Some companies bundle both. Avendo works only with PCI DSS compliant processors and gateways and sits between your checkout and several of them.
Which is better, flat-rate or interchange-plus pricing?: Flat-rate pricing charges one percentage plus a fixed fee on every sale, which is predictable. Interchange-plus passes through the card network cost plus a markup, which CO by U.S. Chamber of Commerce says typically offers lower rates to businesses processing more than $10,000 a month. Your monthly card volume is the deciding factor.
Is Square or Stripe better for an online store?: Tipalti lists the same online rate for both, 2.9% plus 30 cents. Square is built around point of sale hardware and adds online checkout, while Stripe is an online payment API that Tipalti says typically needs a developer. Online-first stores often lean Stripe; stores that also sell in person often lean Square.
Can I use more than one payment processor?: Yes. Memberful notes that many businesses use multiple processors for flexibility and to reduce processing risk. Avendo makes this practical for e-commerce by connecting one checkout to several processors and routing each transaction to the one offering the best available rate in real time, so you do not manage each connection by hand.
Do payment processors charge monthly fees?: Some do and some do not. Tipalti reports that Stripe’s integrated API has no monthly or setup fees, while PayPal Payments Pro costs $30 a month on top of transaction fees. Read the full fee schedule, not only the headline rate. Avendo says it does not bill or charge merchants directly.
Do international card payments cost more?: Often, yes. Memberful lists Stripe at 2.9% plus 30 cents for US cards and 3.9% plus 30 cents for international cards. If you sell across borders, check each processor’s international rate. Routing through Avendo lets each transaction go to the processor offering the best available rate at that moment.

Read all payment processing questions on the FAQ page

Compare your checkout against routing

Ask Avendo how connecting your existing checkout to multiple processors would work for your store.

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