Traffic leaves from infrastructure you do not maintain, which is also what makes the measurement external. A generator on the same host as the target measures the host, not the path a visitor takes. Share CPU between generator and target and the result is wrong in both directions. External traffic removes both errors.
Setup is a registration
Register with a nickname, an email and a password. Free access comes as trial credit from live support or the $0 Basic plan, and neither asks for a card. Credit applied means the Layer4 and Layer7 tabs open, and that is the entire installation: no packages, no agent to patch, no credential sitting on a laptop.
What you can test from here
A site or server you own. Layer4 takes an IP address, a port, a window and a method; Layer7 takes a URL, a window and a method. The two tabs measure different layers, so start with the cheap one: if the packet path holds, the next question is the application, and layer 7 stresser explains that decision.
Where the browser stops
The control surface is a browser, the traffic is not, so your own connection speed never caps the test. What the browser cannot do is hold a session or run a scripted journey, and for those a tool inside your network answers more honestly. Test history belongs to the account, so colleagues on the same plan see the same list; Pro covers five members.
Metrics during the run
Request or packet rate, error rate and latency, refreshed through the run and kept in the panel afterwards. Being able to stop a bad test early matters more than waiting for the summary: when the error rate climbs, cut the rate or end it. A sudden drop on the chart means either you stopped it or the target stopped answering.
Mobile, and locked-down laptops
The panel opens in a mobile browser and on a corporate laptop where installing software is not an option. That portability is underrated: many teams who need a free stresser run cannot install anything on the machine in front of them. Reading two charts side by side is still easier on a desktop, which is where planned windows belong.
Plans and payment
Basic is $0 a month with one concurrent test. Pro is $29 a month for three concurrent tests and five team members. Enterprise is scoped for critical infrastructure and policy controls. Payment is Bitcoin only and activation averages thirty minutes, and the stresser panel shows plan state without a separate invoice screen.
The rule that still applies
Only systems you own or have written permission to test, with confirmation when the target is saved and again at run start. A browser tab is not proof of ownership, and an account that ignores the rule is closed. The IP stresser free account follows the same rule, and IP booter is the product this becomes without that rule.