Web Application Server (WAS or Web AS) is a component of the NetWeaver solution which works as a web application server to SAP solutions. From the SAP point of view the Web AS is the foundation on which most of their product range runs.

Its basic function is to allow web development based on SAP standard solutions (usually developed under the ABAP programming language, but in the newer versions also in Java programming language). With Web AS, it is possible - for example - to publish queries, programs and ABAP applications in a web environment but linked to and based in a SAP solution infrastructure. The newer versions of the (WAS or WEB AS) also support open standards like Java programming language. From the versions 6.20 and higher it is possible to create ABAP only, Java Platform, Standard Edition only or mixed environments.