Eight payment processors tied for first place in StatusBird's latest reliability rankings: Adyen, Affirm, Authorize.net, Braintree, Klarna, PayPal, Plaid, and Stripe each recorded 100% uptime over the past 90 days, with zero major or critical incidents. At the other end of the table, Square posted 99.16% uptime after a single incident that lasted roughly 17 hours, the longest outage of any payment processor we track.
These numbers come from StatusBird's own independent monitoring, which checks each processor's status every 2 minutes, around the clock. Nothing here is self-reported by the vendors. Here is how all 11 payment processors performed over the 90 days ending July 2026.
Payment processor reliability rankings, 90 days to July 2026
| Rank | Service | 90-Day Uptime | Grade | Incidents |
|---|---|---|---|---|
| 1 (tie) | Adyen | 100% | A+ | 0 |
| 1 (tie) | Affirm | 100% | A+ | 0 |
| 1 (tie) | Authorize.net | 100% | A+ | 0 |
| 1 (tie) | Braintree | 100% | A+ | 0 |
| 1 (tie) | Klarna | 100% | A+ | 0 |
| 1 (tie) | PayPal | 100% | A+ | 0 |
| 1 (tie) | Plaid | 100% | A+ | 0 |
| 1 (tie) | Stripe | 100% | A+ | 0 |
| 9 | Afterpay | 99.98% | A+ | 2 |
| 10 | Sezzle | 99.95% | A+ | 1 |
| 11 | Square | 99.16% | B | 1 |
How each payment processor performed
Stripe: 100% uptime, 0 incidents
Stripe is the default card processor for a huge share of online stores and powers Shopify Payments under the hood. Across more than 43,000 independent checks in this 90-day window, we recorded zero major or critical incidents. That is a genuinely clean quarter, though Stripe has had notable outages in the past, so it is still worth having a plan for what to do when Stripe goes down.
PayPal: 100% uptime, 0 incidents
PayPal remains the most widely recognized alternative payment method at checkout, and for many stores it quietly handles 15 to 25% of orders. It matched Stripe with a perfect 90-day record and an A+ grade. As a secondary processor, that consistency is exactly what you want.
Adyen: 100% uptime, 0 incidents
Adyen is the enterprise-grade processor behind many large retailers and platforms, handling cards, wallets, and local payment methods globally. Zero incidents across the window earned it a share of first place. Its reputation for stability held up under independent measurement.
Braintree: 100% uptime, 0 incidents
Braintree, owned by PayPal, is a developer-focused gateway popular with stores that need custom checkout flows or marketplace-style split payments. It went 90 days without a single major or critical incident in our monitoring.
Authorize.net: 100% uptime, 0 incidents
Authorize.net is one of the oldest gateways on the market and still common among stores on legacy or custom platforms. Age did not slow it down: a perfect 100% with zero incidents over the full window.
Klarna: 100% uptime, 0 incidents
Klarna is the largest buy now, pay later provider in most Western markets, and a BNPL outage means those customers simply cannot complete checkout with their preferred method. Klarna gave us nothing to report this quarter: 100% uptime and an A+ grade.
Affirm: 100% uptime, 0 incidents
Affirm handles longer-term installment financing, often for higher-ticket carts, so its availability directly affects your biggest orders. It matched the leaders with a spotless 90-day record.
Plaid: 100% uptime, 0 incidents
Plaid powers bank-account linking for ACH payments and pay-by-bank checkout options. It recorded 100% uptime with zero incidents, though we have roughly 13,000 checks on Plaid versus 40,000+ for most peers because we added it to monitoring more recently. The record is perfect; the sample is just shorter.
Afterpay: 99.98% uptime, 2 incidents
Afterpay is a major BNPL option, especially strong in fashion and beauty. It logged two incidents totaling just 28 minutes of downtime, an average of 14 minutes each, with the most recent on May 8, 2026. Two blips that resolve in a quarter of an hour are close to a non-event, and Afterpay kept its A+ grade.
Sezzle: 99.95% uptime, 1 incident
Sezzle is a BNPL provider popular with smaller and mid-size merchants. Its single incident on July 5, 2026 lasted 62 minutes, recent enough that it happened days before this data snapshot. One hour-long incident in 90 days still earns an A+, but it is worth watching whether it stays a one-off.
Square: 99.16% uptime, 1 incident
Square combines payments with POS hardware, so many merchants rely on it both online and in person. Its lone incident on May 1, 2026 is the story here: 1,030 minutes of downtime, a bit over 17 hours in a single stretch. One long outage hurts far more than several short ones, because 17 hours of degraded payments spans an entire selling day. That single event dropped Square to a B grade and last place in the category.
What this means when you pick a processor
The gap between first and last place looks small in percentage terms, 100% versus 99.16%, but it translates to zero minutes of major downtime versus 17 hours. For a store doing $10,000 a day, that difference is not academic. The other lesson in this data: incident count matters less than incident duration. Afterpay had two incidents and lost 28 minutes; Square had one and lost 1,030.
Whatever you choose, run a backup. Even the eight processors with perfect quarters have had incidents in prior windows, which is why redundancy at checkout beats betting everything on one provider. Our 2026 e-commerce infrastructure reliability report covers how outages cluster across the whole stack.
How we measure reliability
StatusBird independently checks each service's status every 2 minutes, 24/7. The figures above cover the trailing 90 days as of July 2026. Availability counts major and critical outages only; minor degradation is excluded, because some providers report minor issues almost continuously and counting them would bury the signal. Grades run from A+ to F based on uptime and incident history. Live numbers for every service are on our reliability tracker, and the full analysis is in the State of E-commerce Infrastructure 2026 report.
Know the moment your payment processor goes down
StatusBird monitors Stripe, PayPal, Square, and every processor on this list every 2 minutes and sends you an SMS the moment a status change is detected, so you hear about a checkout problem before your customers do. Monitor your payment stack alongside Shopify, Klaviyo, and 80+ other e-commerce services in one dashboard. Start monitoring free.