Don't crash in your next traffic spike. Stress test your website.

Loadster runs thousands of real browsers to stress test your site. Record a script, launch a test, and find your site's breaking point in minutes.

96M
Bots Launched
60K
Sites Tested
7M
Scripts Played
32
Cloud Regions

Loadster has helped improve the performance, scalability, and uptime of thousands of sites. Proud to be chosen by many of the best teams.

  • Nginx
  • Wells Fargo
  • Amazon
  • Queensland Government
  • Accenture
  • Yale University
  • HBO
  • Mint Mobile
  • KPMG
  • Perficient
  • Dell
  • Pearson

Find your site's breaking point... Before your users do.

Your website might be fast and stable right now, under typical traffic. But what happens when thousands of users hit it at once? Stress testing pushes your site beyond its expected capacity to discover what breaks, where, and how it recovers.

Run a controlled stress test on your own schedule — far better than discovering your limits during a product launch, marketing campaign, or flash sale.

Stress Test Your Site

Real headless Chrome browsers or lightweight HTTP clients. Use your choice of Playwright, Browser Bots, or Protocol Bots.

Playwright Bot

Playwright Bots

Run your Playwright Test scripts at scale through Loadster's cloud. Ideal for teams already using Playwright or who want programmatic control with an open source testing framework, combined with Loadster's cloud scaling and reporting.

Scripting Style
JavaScript/TypeScript
Good For Testing
Web Applications, Modern Websites
Fuel Consumption
Loadster Fuel Loadster Fuel Loadster Fuel Loadster Fuel 4X
Playwright Scripts »
Browser Bot

Browser Bots

Record scripts in your browser with Loadster's free extension and edit them visually. Add JavaScript if necessary. Browser Bots automate real headless Chrome browsers for realistic web application testing with a minimal learning curve.

Scripting Style
Visual or JavaScript
Good For Testing
Web Applications, Modern Websites
Fuel Consumption
Loadster Fuel Loadster Fuel Loadster Fuel Loadster Fuel 4X
Browser Bot Scripts »
Protocol Bot

Protocol Bots

Protocol Bots execute scripted HTTP/S requests against your API or static website. Testing at the protocol layer is cost-effective and easily scales to hundreds of thousands of concurrent bots, and is ideal for testing HTTP APIs at scale.

Scripting Style
Visual or JavaScript
Good For Testing
APIs, Simple Websites
Fuel Consumption
Loadster Fuel 1X
Protocol Bot Scripts »
Stress Test Your Site

Loadster scales with your testing and your budget. Choose between flexible pay-as-you-go and subscription pricing.

Monthly Fuel Plans

Starting at $78 a month

Subscribe to a monthly plan to automatically add fuel every month at a discount. Unused fuel rolls over as long as you keep the plan.

Plan Pricing

Pay As You Go

Starting at $97 for 1000 units

Purchase as much Loadster Fuel as you need for your load testing and monitoring. No commitment, just buy it when you need it.

Fuel Pricing
Not quite ready to stress test? Check your site's baseline performance first.

Frequently Asked Questions

Is the free tier really free?
Yes. Every account starts with 50 free units of Loadster Fuel — enough for a handful of tests. No credit card required to start. You only pay if and when you decide to scale up beyond your starting fuel.
How do I run my first stress test?
Sign up, install the free Loadster Recorder browser extension, record a script that walks through your site, then launch a stress test from the dashboard. The first test usually takes about 5-10 minutes from signup to results.
How is stress testing different from load testing?
Load testing confirms a site handles expected peak traffic. Stress testing deliberately exceeds expected capacity to find the breaking point. Both use the same tooling; the difference is in the ramp pattern and what you’re looking for.
Can I stress test a production site?
You can, but coordinate with your team and pick a low-traffic window. Stress tests deliberately push past expected capacity, so there’s a real risk involved. Many teams stress test in a staging environment first, then verify in production once they know what to expect.