Payment Gateway API, Simulation& Integration Testing Platform

Simulate payment gateway flows and test your payment integrations before going live with hosted checkout, signed webhooks, failure scenarios, and edge cases on demand.

Start Testing Free Try Demo
curl -X POST https://mockgateway.com/api/base/stripe-demo/v1/payment_intents \
-H "Authorization: Bearer sk_test_stripe_demo_public" \
-H "Content-Type: application/json" \
-d '{
"amount": 2500,
"currency": "USD",
"return_url": "https://mockgateway.com/payment/return" }'
→ returns "payment_url": "https://mockgateway.com/pg/pay/6f35d1b3…"

Templates modelled on these gateways (and more)

Stripe logoStripePayPal logoPayPalRazorpay logoRazorpayBraintree logoBraintreeAdyen logoAdyenMollie logoMollie2Checkout logo2CheckoutSquare logoSquare

Why Developers Choose MockGateway?

Web developers often find that testing a payment integration against a gateway can be harder than it should be. Sandboxes can be slow or unreliable. Some failures are difficult to reproduce when you need them.

  • Hard-to-trigger failures: Declines and timeouts are not easy to reproduce.
  • Webhook setup: Testing often means setting up a tunnel.
  • Flaky CI tests: Sandbox behaviour can make tests unreliable.
  • Slow sandbox access: Getting access can take days.
  • Setup per gateway: Every provider has its own sandbox and test data.
  • Money at risk: One wrong live key can cause a real charge.
Test Payment Integrations Without the Sandbox
MockGateway gives you a simple way to test your payment integration before going live.
  • Trigger any scenario: Declines, timeouts, retries, and 3D Secure.
  • Test signed webhooks: Automatic retries when your endpoint fails.
  • Keep tests predictable: Same flow, same response, every run.
  • Start in 60 seconds: No need to wait for sandbox access.
  • 14+ gateway templates: Test multiple gateways from one account.
  • No real money involved: No merchant account or live keys needed.
Try the interactive demo Start testing for free

How MockGateway Works?

Pick a gateway template, send a payment request, choose the outcome on the checkout page, and receive the webhook. The whole round trip takes under a minute. Click any step to follow it.

POST /api/base/stripe-demo/v1/payment_intents
{
"amount": 2500,
"currency": "USD",
"return_url": "https://yourapp.dev/callback"
}

Same API path as production. Every gateway gets a simulated base URL (https://mockgateway.com/api/base/{slug}). The path after it is identical to the real provider's own API, e.g. Stripe's /v1/payment_intents. Point your app at it in sandbox, then swap only the base URL when you go live, with no code changes.

Read the full integration guide

Built-In Test Scenarios for Every Edge Case

The outcomes your real gateway will eventually return are preconfigured, deterministic, one click away.

Success
Failed / Declined
Cancelled
Timeout
Retry / Pending
3D Secure / SCA
Custom HTTP Errors
Redirect Chains
Webhook Variants

Start Testing Payments in Minutes

Create a mock payment gateway with a real API endpoint, hosted checkout page, and webhook delivery with no credentials required.

Start Testing Payments Free View API Docs

MockGateway is in active development and improving fast.

Free forever: 500 test payment requests per month. See pricing·Read the FAQ