StresStimulus provides flexible licensing options to fit various business, technical and budget requirements. To select a license, choose:
  • an edition
  • licensing model
  • number of virtual users
  • and license duration.
StresStimulus comes in the following four editions:
  • Pro
  • Enterprise
  • Service Provider
  • and Free.
For more details, check the Edition Comparison Chart.
These are two licensing models that are currently offered.

  • With a per-machine license, a serial number is activated on one machine at a time. In the Enterprise/SP editions, serial numbers can be moved to different machines. In addition to the currently activated controller, you can use multiple load generation agent machines which do not require activation.

  • A multi-machine license allows to divide the licensed number of VUs between the purchased number of test machines, which can run tests independently.

  • Moving licenses and re-allocating VUs between machines requires Internet connectivity to communicate with StresStimulus's licensing server and an active maintenance plan.
If you use a server with several testers logged-in, then each of them can use StresStimulus, but not concurrently with other testers. Tester 1 would need to close StresStimulus for Tester 2 to start it. Only one instance of StresStimulus can run on a machine. A single per-machine license covers this type of use.
With a multi-machine license you can run multiple independent tests concurrently by dividing the purchased number of VUs between licensed machines.
A multi-machine license is a more economical way to share licensed virtual users within a team to conduct independent performance tests.
Before purchasing a multi-machine license you need to decide how many virtual users you would need for all your concurrent tests and what the maximum number of machines you will use.
Multi-machine licenses can be purchased online for 2-10 machines. For more machines, contact us.
You will receive a single serial number to activate all of your test machines
You can allocate the necessary number of VUs from the shared pool of licensed VUs. Released VUs immediately become available to use on other test machines. For example, if you purchase 500 VUs for 3 machines, you can activate 100 VUs on machine 1, 150 VUs on machine 2 and 250 VUs on machine 3. After that, you can run 3 independent tests. You can change VU allocations between the machines as long as the total number of VUs does not exceed 500. Re-allocation requires Internet access and active maintenance. You will receive one free VU per every additional test machine, for scripting. These scripting VUs and purchased VUs cannot be combined on the same machine.
The per-machine license can be used on one machine at a time. It can be moved to different machines, but requires deactivation on the previous machine. Activation / deactivation requires Internet access and active maintenance.
A one-time connection to the Internet is required to connect to our licensing server and activate a trial or a commercial license. Unregistered trials with 3 VUs do not require activation. Also, with subscriptions an Internet connection is required for auto-renewals at the beginning of each subscription period. At other times, internet connection is not required.
Yes. You can use the offline activation option, which requires the following steps. (1) During activation you will receive the "Internet Connection Failed" message. Click the "Activation Request" button. (2) A prompt to create a request file will appear. Click the "Save Request File" button to save the file to your disk. (3) Email the saved file to We will send you a key for offline activation within one business day. The key will replace the serial number received with your purchasing invoice or trial welcome email.
The offline activation license is available only with a per-machine permanent or annual license. It is not available with subscriptions.
We offer weekly, monthly, quarterly, annual and permanent licenses. Monthly and quarterly licenses can be purchased only on a subscription basis. Subscriptions are auto-renewable. Annual licenses and weekly passes are not auto-renewable.
To avoid future charges, you need to cancel the subscription at any time before the end of the current subscription period. After cancellation, your license will work until the end of the prepaid period. After the subscription is auto-renewed, a refund for the unused period will be not provided.
Your original purchase receipt has a link to the cancellation webpage. To cancel the subscription, you would need to enter your serial number and your original order or invoice number. Alternatively, you can request cancellation by calling or emailing us.
Our licensing fee is based on issuing you a license for the subsequent billing period. It is not based on your usage and we do not have control over that. Furthermore, once the license is issued we cannot automatically revoke it. After order renewal, your test machine will be licensed to continue to use StresStimulus until the end of the current prepaid period. Therefore, we are unable to refund you.
Both per-machine and multi-machine licenses can be used with monthly and quarterly subscriptions.
Download and install StresStimulus. No registration is required. Start using your trial version that has all StresStimulus features but is limited to 3 VUs. Install it on as many machines as you need. To receive more VUs, try the registered trial (see the next question).
Complete the registration form to receive an email with an activation key to start your 7-day extendable trial of StresStimulus.
After activating your 7-day trial on one machine, provide us with details about your evaluation requirements and we will be in touch to provide you a larger-scale trial. The easiest way to contact us is to click "Email Support" in the StresStimulus menu to generate an email with your trial serial number. Provide details and send the email to
During the free registered trial you will receive the same level of support that is available to our customers with the premium support plan. Plus, your first test configuration is on us. Learn more.
Yes. StresStimulus free edition is designed for simple load tests with up to 250 VUs. Compared to premium editions, it has limited reporting and several other limitations. The free edition can be used on as many machines as you need and never expires.
A single download of StresStimulus includes the premium version and the free Edition. After downloading the trial, simply click "Use Free Edition" in the StresStimulus menu. You always can go back to the premium version.