Beeceptor - Unblock yourself from API dependencies, and build & integrate with APIs fast. Beeceptor helps you build a mock Rest API in a few seconds.
Postman - The Collaboration Platform for API Development
Webhook.site - Instantly generate a free, unique URL and email address to test, inspect, and automate (with a visual workflow editor and scripts) incoming HTTP requests and emails.
DreamFactory - DreamFactory is an API management platform used to generate, secure, document, and extend APIs.
MockServer - Easy mocking of any system you integrate with via HTTP or HTTPS.
AWS CloudTrail - AWS CloudTrail is a web service that records AWS API calls for your account and delivers log files to you.