WireMock : Free and Open Source tool for building mock APIs. Create stable development environments, isolate yourself from flakey 3rd parties and simulate APIs t...
BlurHash : BlurHash is a compact representation of a placeholder for an image.
httpbin.org : A simple HTTP Request & Response Service.
Matrix : Matrix is an open standard for decentralised communication, providing simple HTTP APIs and open source reference implementations for securely distribu...
Mockbin : Mockbin allows you to generate custom endpoints to test, mock, and track HTTP requests & responses between libraries, sockets and APIs.
Mockoon is the easiest and quickest way to design and run mock APIs. No remote deployment, no account required, free and open-source.