Head to head
Mollie vs Square
As a payments API, Square rates higher on the APIbenchmarks Index, 85.9 to 81.4, a 4.5-point gap. Here is how they compare on each criterion.
Criterion by criterion
| Criterion | Mollie | Square |
|---|---|---|
| Documentation & DX | ||
| Reliability | ||
| Ecosystem & SDKs | ||
| Accessibility | ||
| APIbenchmarks Index | 81.4 | 85.9 |
Specifications
| Mollie | Square | |
|---|---|---|
| Best for | European local-payment-methods PSP | Omnichannel (online + in-person) payments |
| Free tier | No setup/monthly fee; test mode free, pay per transaction | Free APIs/SDKs + sandbox; sellers pay per transaction |
| Pricing | Per transaction (1.8% + €0.25 EU cards) | Per transaction (2.6% + $0.15 in-person) |
| Official SDKs | 8 languages | 12 languages |
Is Mollie better than Square?
On the APIbenchmarks Index, Square rates higher (85.9 vs 81.4). It leads on the four weighted criteria, but price is reported separately, so the best choice still depends on your budget.
Verdict in one line
Square leads by 4.5 points (85.9 vs 81.4) and wins 4 of 4 criteria.
Winner by criterion
| Criterion | Winner | ||
|---|---|---|---|
| Documentation & DX | 84 | 86 | |
| Reliability | 80 | 86 | |
| Ecosystem & SDKs | 76 | 84 | |
| Accessibility | 86 | 88 |
Choose Mollie if… / choose Square if…
- →your use case matches its focus: european local-payment-methods psp
- →documentation & dx matters most to you (86 vs 84)
- →reliability matters most to you (86 vs 80)
- →ecosystem & sdks matters most to you (84 vs 76)
- →accessibility matters most to you (88 vs 86)
- →you need broad SDK coverage (12 official SDKs vs 8)
- →your use case matches its focus: omnichannel (online + in-person) payments
Pricing side by side
- Model
- Per transaction (1.8% + €0.25 EU cards)
- Free tier
- No setup/monthly fee; test mode free, pay per transaction
- Online, Cards (EEA consumer Visa/Mastercard)1.80% + €0.25
- Online, Cards (EEA commercial / American Express)2.90% + €0.25
- iDEAL / Wero€0.32
- Bancontact1.40% + €0.25
- SEPA Direct Debit / Bank Transfer€0.35 / €0.25
- In-person, Pro Plan€20 / month
- Model
- Per transaction (2.6% + $0.15 in-person)
- Free tier
- Free APIs/SDKs + sandbox; sellers pay per transaction
- Square Free$0/mo
- Square Plus$49/mo
- Square Premium$149/mo
- Online API2.9% + 30¢
- ACH via API1%, $1 min, $5 cap
- Custom / EnterpriseCustom
Vendor-published pricing, verified 2026-06-27 (Mollie) and 2026-06-27 (Square).
SDK and language coverage
Both · 5
PHP (mollie-api-php)Python (mollie-api-py)RubyJavaGo (Golang)
Only Mollie · 3
Laravel Cashier (PHP)Node.js / TypeScript (mollie-api-node)C# / .NET
Only Square · 7
Node.js.NET (C#)Web Payments SDK (JavaScript)In-App Payments SDK (iOS)In-App Payments SDK (Android)React Native pluginMobile Payments / Terminal SDK
Strengths and weaknesses
- +Transparent blended pricing with no setup, monthly minimum or cancellation fees on the standard online product, you pay only on successful transactions
- +Excellent European payment-method coverage out of the box (iDEAL, Bancontact, Klarna, SEPA, PayPal, Apple/Google Pay, 40+ methods)
- +Clean, well-documented REST API with reliable webhooks and strong recurring/subscription handling that developers praise
- –Recurring, serious merchant complaints about sudden account holds, collateral reserves and frozen funds with poor communication (reflected in a low 3.2/5 Capterra score)
- –Settlement/payout timing in practice can lag the documented ~5 business days, with reports of cards taking 2–3 weeks and Klarna up to two months in disputed cases
- –Europe-centric: weaker fit than Stripe/Adyen for US-first or truly global expansion
- +Single API and account unifies online, in-app, and in-person (omnichannel) payments
- +Transparent flat-rate pricing with no monthly fee, PCI fee, or minimums on the free tier
- +Broad payment-method support: cards, Apple/Google/Cash App Pay, ACH, Afterpay, gift cards
- –Risk-driven account freezes and fund holds with little notice are a recurring, serious complaint
- –Phone support limited to first 90 days; slow, hard-to-escalate help for complex issues
- –Flat-rate pricing becomes expensive at high volume versus interchange-plus processors
Mollie vs Square: questions
- Which has better documentation, Mollie or Square?
- Square scores higher on documentation and developer experience: 86 vs 84 out of 100.
- Which is more reliable, Mollie or Square?
- Square scores higher on reliability: 86 vs 80 out of 100.
- Do Mollie and Square have a free tier?
- Mollie: yes (No setup/monthly fee; test mode free, pay per transaction). Square: yes (Free APIs/SDKs + sandbox; sellers pay per transaction).
- How are Mollie and Square priced?
- Mollie: Per transaction (1.8% + €0.25 EU cards). Square: Per transaction (2.6% + $0.15 in-person).
- Which has more official SDKs?
- Square lists 12 official SDKs, Mollie lists 8.