PHP developers can learn how to merge multiple PDF files into a single PDF file using PHP REST API and SDK. To merge PDFs, you need to upload input PDFs to Aspose for Cloud Service or any supported third party storage and then send a PUT request to Aspose for Cloud service. Aspose.Pdf for Cloud allows you to create, read, update, merge, split or convert PDFs in any language including .NET, Java, PHP, Ruby, Rails, Python, jQuery and many more. You can use it with any language or platform that supports REST. (Almost all platforms and languages support REST and provide native REST clients to work with REST APIs).