WireMock : Free and Open Source tool for building mock APIs. Create stable development environments, isolate yourself from flakey 3rd parties and simulate APIs t...
mountebank : mountebank is the first open source tool to provide cross-platform, multi-protocol test doubles over the wire. Simply point your application under tes...
Mockbin : Mockbin allows you to generate custom endpoints to test, mock, and track HTTP requests & responses between libraries, sockets and APIs.
httpbin.org : A simple HTTP Request & Response Service.
BlurHash : BlurHash is a compact representation of a placeholder for an image.
Mockoon is the easiest and quickest way to design and run mock APIs. No remote deployment, no account required, free and open-source.