Best Online Card Payment APIs
Opinionated picks for online card payment apis, with the trade-offs up front, judged from each API’s published, cited data. The reasoning is shown, so disagree where you know better. Compare all 14 →
Best overall: PayPal Payments
PayPal Payments is a REST API for accepting payments across 200+ markets, 130+ currencies, and 30+ payment methods, covering ecommerce checkout, subscriptions, invoicing, marketplace payouts, and in-person payments. Pricing is per-transaction: standard card rates start at 2.89% + $0.29 for advanced card processing, with an interchange-plus option for eligible merchants and an additional 1.50% fee on cross-border transactions. The API supports OAuth2, webhooks, idempotency, a sandbox, and SDKs for six languages, and holds SOC 2 Type 2, ISO 27001, and PCI DSS Level 1 certifications.
From $0.29 transaction + percent.
How it stacks up
- ✓ PayPal Payments starts lower at $0.29 transaction + percent vs $0.30 for Square Payments.
- ✓ For coding-agent use, Adyen scores higher on agent-friendliness (75 vs 65).
- ✓ On compliance, PayPal Payments additionally documents SOC 2.
Best for: Regulated or enterprise workloads - compliance attestations and an enterprise plan; AI agents and automation - an agent-ready surface (MCP / llms.txt); Teams needing broad API coverage out of the box.
Avoid if: You want to try it free before paying
At a glance
| # | API | Best for | Starting price | Score |
|---|---|---|---|---|
| 1 | PayPal Payments | Best overall · Best for enterprise · Best for agents | $0.29 transaction + percent | 68 |
| 2 | Square Payments | transparent public pricing | $0.30 transaction + percent | 68 |
| 3 | Adyen | transparent public pricing | $0.13 transaction | 64 |
| 4 | Razorpay | transparent public pricing | - | 64 |
| 5 | Stripe | Broadest surface | - | 63 |
| 6 | Authorize.net | transparent public pricing | $0.10 transaction | 53 |
| 7 | Braintree (PayPal) | transparent public pricing | $0.29 transaction + percent | 46 |
| 8 | Mollie | transparent public pricing | - | 54 |
| 9 | Worldpay | transparent public pricing | - | 35 |
| 10 | Checkout.com | SOC 2 Type II | - | 44 |
| 11 | Helcim | Cheapest to start | $0.08 transaction + percent | 50 |
| 12 | Cybersource (Visa Acceptance) | GDPR | - | 39 |
| 13 | Rapyd | SOC 2 Type II | - | 41 |
| 14 | Nuvei | GDPR | - | 28 |
Quick pick by use case
- If you want the strongest all-round pick, pick PayPal Payments - our default pick: strongest across pricing, trust and breadth.
- If you're buying for a regulated or large team, pick PayPal Payments - for regulated or large teams: SOC 2 Type II, enterprise plan.
- If you want the lowest published entry price, pick Helcim - from $0.08 transaction + percent to start; compare on your real usage, not the entry price.
- If you're wiring this into coding agents or AI workflows, pick PayPal Payments - easiest to wire up programmatically: MCP server + llms.txt.
- If you want the broadest documented surface, pick Stripe - 304 documented actions; breadth isn't quality, but it's the most to build on.
The picks in depth
#1 PayPal Payments
68 / 100- Best overall
- Best for enterprise
- Best for agents
PayPal Payments is a REST API for accepting payments across 200+ markets, 130+ currencies, and 30+ payment methods, covering ecommerce checkout, subscriptions, invoicing, marketplace payouts, and in-person payments. Pricing is per-transaction: standard card rates start at 2.89% + $0.29 for advanced card processing, with an interchange-plus option for eligible merchants and an additional 1.50% fee on cross-border transactions. The API supports OAuth2, webhooks, idempotency, a sandbox, and SDKs for six languages, and holds SOC 2 Type 2, ISO 27001, and PCI DSS Level 1 certifications.
PricingHybrid · from $0.29 transaction + percent · free tier ✗TrustSOC 2 Type II · GDPR · ISO 27001 · PCI DSSDoesUsed byTicketmaster, Grubhub, Southwest Airlines, HelloFreshStrengthstransparent public pricing · self-serve signup · SOC 2 Type IIAvoid ifYou want to try it free before payingScoresAgent 65 · Pricing 85 · Setup 75 · Docs 30 · Procurement 85 · Trust 65#2 Square Payments
68 / 100Square Payments is a REST API for in-person, online, and mobile payment processing, covering use cases from hosted checkout and payment links to recurring subscriptions and marketplace payments. It operates in eight countries including the US, UK, Canada, Australia, and Japan, with published per-transaction pricing starting at $0.30 plus a percentage and a self-serve signup path. The API supports OAuth2 and API key auth, webhooks, idempotency, and ships official SDKs for seven languages including Node.js, Python, and Go. Security certifications include PCI DSS Level 1, SOC 2 Type 2, ISO 27001, and GDPR compliance.
PricingHybrid · from $0.30 transaction + percent · free tier ✗TrustSOC 2 Type II · GDPR · ISO 27001 · PCI DSSDoesUsed byShake Shack, Boston Beer CompanyStrengthstransparent public pricing · self-serve signup · SOC 2 Type IIAvoid ifYou want to try it free before payingScoresAgent 65 · Pricing 85 · Setup 75 · Docs 35 · Procurement 85 · Trust 65#3 Adyen
64 / 100Adyen is a payments platform covering ecommerce checkout, in-person POS, marketplace splits, recurring billing, card issuing, and payouts across approximately 100 countries. Pricing starts at $0.13 per transaction with published indicative rates, though final pricing requires a sales conversation and going live involves an underwriting review with a minimum invoice threshold. The REST API ships with SDKs for seven languages, supports webhooks and idempotency, and holds SOC 2 Type II, ISO 27001, and PCI DSS Level 1 certifications.
PricingSales-led · from $0.13 transaction · free tier ✗TrustSOC 2 Type II · GDPR · ISO 27001 · PCI DSSDoesUsed byMeta, Uber, eBay, MicrosoftStrengthstransparent public pricing · SOC 2 Type II · GDPRAvoid ifYou want to try it free before payingScoresAgent 75 · Pricing 70 · Setup 75 · Docs 25 · Procurement 55 · Trust 85#4 Razorpay
64 / 100Razorpay is a payment platform founded in 2014 and primarily aimed at India-based businesses, offering payment acceptance, marketplace split payments, subscription billing, payouts, and no-code checkout tools across 160+ currencies. Pricing is usage-based with published per-transaction rates, self-serve signup, and custom pricing for merchants processing over Rs. 5,00,000 per month. The REST API supports seven SDK languages, webhooks, idempotency, and OAuth2 authentication, and Razorpay holds PCI DSS Level 1 certification, ISO 27001, and GDPR compliance.
PricingUsage · free tier ✗TrustGDPR · ISO 27001 · PCI DSSDoesUsed byZerodha, makeMYtrip, Zoomcar, LiciousStrengthstransparent public pricing · self-serve signup · GDPRAvoid ifYou want to try it free before payingScoresAgent 70 · Pricing 60 · Setup 75 · Docs 65 · Procurement 75 · Trust 40#5 Stripe
63 / 100- Broadest surface
Stripe is financial infrastructure for accepting and optimizing payments online and in person, with support for billing models, card issuing, cross-border money movement, and embedded payments for platforms. Pricing is usage-based, published, and self-serve. It offers webhooks, an official MCP server, and seven SDKs, and carries SOC 2 Type 2, GDPR, and PCI DSS compliance.
PricingUsage · free tier ✗TrustSOC 2 Type II · GDPR · PCI DSSDoesStrengthstransparent public pricing · self-serve signup · SOC 2 Type IIAvoid ifYou want to try it free before payingScoresAgent 75 · Pricing 60 · Setup 65 · Docs 55 · Procurement 75 · Trust 50#6 Authorize.net
53 / 100Authorize.net is a payment gateway, operated by Visa subsidiary CyberSource, that handles ecommerce checkout, recurring billing, in-person card payments, virtual terminal orders, and mobile POS for merchants in the United States, Canada, Australia, and New Zealand. Pricing is hybrid: a per-transaction fee starting at $0.10 with a $25 monthly minimum, and an All-in-One plan that bundles a merchant account for businesses without one. The REST API supports six major languages, webhooks, tokenization, and Apple Pay and Google Pay, with a sandbox available for testing. PCI DSS compliance is confirmed; SOC 2 is not available, and a SOC 1 report can be requested by account owners only.
PricingHybrid · from $0.10 transaction · free tier ✗TrustGDPR · PCI DSSDoesStrengthstransparent public pricing · self-serve signup · GDPRAvoid ifYou want to try it free before payingScoresAgent 30 · Pricing 85 · Setup 75 · Docs 15 · Procurement 85 · Trust 25#7 Braintree (PayPal)
46 / 100Braintree, a PayPal company launched in 2007, is a global payment processing platform covering card acceptance, tokenization, subscription billing, marketplace split payments, and in-person terminals across 200+ markets. Pricing is usage-based at a published rate starting at $0.29 per transaction plus a percentage, though production merchant accounts require a sales contact and underwriting rather than self-serve signup. The GraphQL API ships SDKs for seven languages, supports webhooks and idempotency, and holds PCI DSS Level 1, SOC 2 Type 2, ISO 27001, and GDPR certifications. Notable customers include Uber, Airbnb, GitHub, and Facebook.
PricingUsage · from $0.29 transaction + percent · free tier ✗TrustSOC 2 Type II · GDPR · ISO 27001 · PCI DSSDoesUsed byUber, Airbnb, GitHub, OpenTableStrengthstransparent public pricing · SOC 2 Type II · GDPRAvoid ifYou need to start building today without contacting salesScoresAgent 45 · Pricing 70 · Setup 40 · Docs 25 · Procurement 30 · Trust 65#8 Mollie
54 / 100Mollie is a European payments platform offering online and in-person payment processing for businesses of all sizes across 30+ EEA markets, covering ecommerce checkout, subscriptions, marketplaces, payouts, and payment links. Pricing is transaction-based (flat fee plus percentage) with published rates and self-serve signup; volume IC++ pricing is available for merchants processing over 100,000 euros per month via sales. The REST API supports OAuth2, idempotency, webhooks, and SDKs for seven languages, and Mollie is PCI DSS Level 1 certified and GDPR compliant.
PricingUsage · free tier ✗TrustGDPR · PCI DSSDoesUsed byRosefield, Lounge Underwear, Maisons du Monde, VelorettiStrengthstransparent public pricing · self-serve signup · GDPRAvoid ifYou want to try it free before payingScoresAgent 65 · Pricing 60 · Setup 75 · Docs 25 · Procurement 75 · Trust 25
How we rank
The headline score is the average of six 0-100 axes computed only from each API’s published, sourced fields: agent-friendliness, pricing transparency, setup speed, docs quality, procurement ease, and trust readiness. An unknown signal scores 0 for its axis - we credit what’s confirmed, never guess. The score is one input, not the verdict: we lead with each pick’s trade-off, and where a job has only one real option we say so rather than crown it. Full method on the methodology page.
Why trust apio
- ✓ Every field cited. Each profile links the source for every claim - check us.
- ✓ Public audit log. Every change to this data is recorded per field, with who changed it and why.
- ✓ Published, deterministic methodology. The score is a formula over the same fields you can see - recompute it yourself.
- ✓ Zero affiliate links, zero ads, zero paid placement. Money never moves rank.
- ✓ No reviews yet - and we say so rather than synthesizing them.
Frequently asked questions
What is the best online card payment api?
PayPal Payments is our current top pick across pricing, trust, and developer-surface data (from $0.29 transaction + percent). The right pick depends on your constraint: if you want the strongest all-round pick, PayPal Payments; if you're buying for a regulated or large team, PayPal Payments; if you want the lowest published entry price, Helcim.
How are these Online Card Payment APIs ranked?
By a transparent data-readiness score computed from each API's published, sourced fields: pricing, free tier, self-serve access, compliance, webhooks/sandbox, and capability breadth. No reviews, no paid placement.