HP LoadRunner is the industry standard for application performance testing. The load testing tool helps you prevent issues by detecting bottlenecks and to obtain an accurate picture of end-to-end system performance before going live. Extremely flexible for organizations and projects of all sizes, LoadRunner software testing tool enables you to test a range of applications including mobile, Ajax, Flex, HTML 5, .NET, Java, GWT, Silverlight, SOAP, Citrix, ERP and legacy.

Verisium (vPerformer) is a performance testing tool that is used to measure the performance, scalability and load stress capacity of web applications. vPerformer is capable of instantaneous large-scale virtual load generation in the cloud that would often be too costly and time consuming for you to setup internally. Dynamic load generation allows you to test against any number of virtual users, and pay only for the time your tests are running. The vPerformer Cloud realistically models user traffic by enabling you to run vPerformer Load Agents at different locations around the globe. vPerformer provides you with the tools to monitor not just the web application under test but also any of its associated components. This includes web servers, application servers, database servers, operating systems, network components, and the various SNMP implementations. This allows you to locate performance bottlenecks and pinpoint the root causes of any performance issues. Unlike many other performance testing tools, monitoring features are available in vPerformer at no additional cost.

Apache JMeter is open source load testing tool. Primarily a performance testing tool, it can also be integrated with the test plan. In addition to the load test plan, you can also create a functional test plan. This tool has the capacity to be loaded into a server or network so as to check on its performance and analyze its load under different conditions. Initially, it was introduced for testing web applications, but later its scope widened. It is of great use in testing the functional performance of resources such as Servlets, Perl Scripts and JAVA objects. Need JVM 1.4 or higher to run.

WebLOAD is a load testing and stress testing tool for web applications. This tool can be used for Load testing any internet applications such as Ajax, Adobe Flex, Oracle Forms and much more. Through WebLOAD, you have the ability to measure the working performance and also its response to the users. This award winning tool was developed by Radview Software. WebLOAD is widely used in environments where there is a high demand for maximum load testing, as it gives you clear information on the functionality and the actual capacity of the web applications.

Loadster is a desktop based, advanced HTTP load testing tool. The web browser can be used to record the scripts which are easy to use and record. Using the GUI you can modify the basic script with dynamic variables to validate response. With control over network bandwidth you can simulate large virtual user base for your application stress tests. After a test is executed, an HTML report is generated for analysis to help identify performance bottlenecks in your application.

Open STA stands for Open System Testing Architecture. This is a GUI based performance tool used by application developers for load testing and analyzing. A complex tool, it has proven capability and the current toolset is capable of performing a heavy load test and analysis for the scripted HTTP and HTTPS. The testing is executed by using the recordings and simple scripts. To carry out the test successfully, results and other statistics are taken through various test runs. This data can be later exported as reports. This is a free testing tool and it is distributed under GNU by Cyrano, which was later taken over by Quotium.

Loadstorm is a cloud testing tool for web applications. With Loadstorm, you have the option of creating your own test plans, testing criteria, and testing scenarios. You can generate up to 50,000 concurrent users in the cloud infrastructure, which enables you to send a large amount of requests per second. There are thousands of servers available around the world for this software, and there is no need of any scripting knowledge to use it. Loadstorm provides many graphs and reports that measure the performance in various metrics such as error rates, average response time and number of users. This tool is available for free, but the premium account comes with added features.

Httperf is a high performance testing tool for measuring and analyzing the performance of any web services and web applications. This is mainly used to the test the HTTP servers and its performance. The main objective of this testing tool would be to count the number of responses generated from this particular server. This generates the HTTP GET requests from the server which helps in summarizing the overall performance of the server. Through this tool, you will be able to conclude the rate at which the response is sent from each server and thereby the efficiency can be calculated. The ability to sustain the server overload, support the HTTP/1.1 protocol and compatibility with new workload are the three key features of this performance testing tool. This was originally developed by David Mosberger and many others at HP.

OctoPerf is a SaaS software aimed to improve quality and performance of web and mobile applications. OctoPerf lets you create thousands of realistic virtual users in a few clicks. No code to write, it all happens in the intuitive GUI. With the essence of JMeter, its core features, Octoperf is a performance testing service on top of it. So you can benefit from the power of the best Open-Source load testing tool without even bothering installing it. It allows to import JMX records and export reports. Its reactive and modern GUI made with AngularJS lets helps to design realistic virtual user in an accessible way. It is also capable of generating performance tests reports. These reports are populated with live metrics thanks to ElasticSearch. Amazon Web Services and Mesos allows you to simulate users visiting your website or application from across the globe.