Postman, soapUI, HTTP Toolkit, Graphical HTTP Client, Thunder Client, Bruno, Hoppscotch, Milkman, Insomnium, Apibucket.io, Advanced REST Client, RapidAPI for Mac, Runscope, Guide API, NativeRest, HttpRequester, Restfox, REST Client for Android, RESTed, Nozomi, HttpMaster, Resting, Iron Test, Assertible, rest-client, Restlet, JunoRestClient, WebMaestro, TestMace, Bearer, RESTtest, GraphicalHttpClient, CurlHub.io, Droptice, FRequest are some alternatives to Insomnia REST Client.