Your site has a breaking point. Stress test to find it before your users do.

Don't crash in a traffic spike! Load test your site with thousands of bots to prepare for heavy traffic and prevent downtime.

Loadster is the load testing tool for modern websites, web apps, and APIs

Every site, web application, and API has its breaking point. Yours might be fast and bug-free most of the time, only to crash under heavy traffic.

Downtime at the worst possible moment, like during a public launch or a marketing campaign or an unexpected traffic spike, costs you business and hurts your reputation.

Load testing (or stress testing) your site is the best way to simulate peak traffic conditions and prevent site crashes.

With Loadster, you'll be running your first load test and getting actionable results in minutes.

Start testing for free

Prevent crashes and downtime by simulating peak traffic conditions

A flood of traffic to your site is a welcome opportunity... as long as the site stays up and delivers a fast experience to everyone.

But if your site crashes or gets broken and sluggish, you'll waste the traffic and damage your reputation.

Load testing helps you prepare your site to handle heavy traffic, and Loadster makes it easy to get started.

If you're ready, create a free account or read our short Introduction to Load Testing for a little more background.

Load test with real Chrome browsers or automated HTTP clients

Browser Bot

Browser Bots control real headless Chrome browsers, for the most realistic load testing possible. Automating thousands of real browsers is the ideal way to stress test your web apps and modern websites.

Best For
Web Applications, Modern Websites
Fuel Consumption
Loadster Fuel Loadster Fuel Loadster Fuel Loadster Fuel
Protocol Bot

Protocol Bots execute scripted HTTP/S requests against your API or static website. Testing at the protocol layer is cost-effective and scales to hundreds of thousands of bots.

Best For
APIs, Simple Websites
Fuel Consumption
Loadster Fuel

Realistic scripting, distributed load tests, and actionable test results

  • Step 1

    Rapidly create your test scripts

    Record load test scripts right in your browser, with the Loadster Recorder extension for Chrome or Firefox. Just step through your site like a real user would while Loadster records every step into a script. After recording, play your script back in real time, and edit it if necessary.

    It's simple to add custom validation and capture server responses to reuse later in the script. Not powerful enough for you? Try JavaScript Code Blocks for advanced control flow, looping, and conditionals.

  • Step 2

    Launch distributed cloud tests in seconds

    Configure your test scenario with groups of bots in regions of your choosing, running your scripts, ramping the load up and down, to simulate the geographically distributed traffic you see in the real world.

    Loadster's got what you need to run globally distributed cloud tests with minimal setup. No need to deploy your own instances to run test infrastructure! In about 90 seconds, Loadster can launch tens of thousands of bots across hundreds of cloud instances in regions of your choosing.

  • Step 3

    Analyze results with quick reporting

    While a load test runs, Loadster gives you realtime metrics on response times (average and percentile), network and transaction throughput, errors, and more.

    After it finishes, the same data is instantly available in a test report you can hold on to or share with your team.

    The metrics and report data inform you how your site handled the traffic, what kind of performance your real users can expect when the site's under a similar amount of load, and where the hot spots and bottlenecks might be.

Everything you need to move faster with your load testing

  • Speedy script recording

    Speedy script recording

    Record scripts right in your browser with the free Chrome or Firefox extension. Or add steps manually.

  • Browser-based editing

    Browser-based editing

    Add steps, edit them, and tweak your script to perfection. All in your web browser.

  • Rapid script feedback

    Rapid script feedback

    Play scripts from your web browser, and watch in real time as each step runs. Repeat as necessary!

  • Detailed diagnostics

    Detailed diagnostics

    After your script runs, you'll see requests, responses, screenshots, and errors from every step.

  • Fully managed cloud

    Fully managed cloud

    No need install any infrastructure! Loadster spins up fully managed cloud instances in about 90sec.

  • Live test results

    Live test results

    As a test runs, watch the charts in real time. Monitor response times, throughput, errors, and more.

  • Automatic test reports

    Automatic test reports

    Loadster generates a full test report with charts and tables after every test. No tedious manual reporting.

  • Team collaboration

    Team collaboration

    Anyone on your team can create scripts, run tests, and share results. Make scalability a team effort!

Launch tests from 29 global cloud regions or your own self-hosted engines

Loadster world coverage

Flexible pay-as-you-go pricing or a predictable monthly plan

  • Pay As You Go

    Starting at $97 for 1000 units

    Buy Loadster Fuel and run load tests in any of 29 cloud regions. No commitment. Simply purchase more fuel when you run out!

    View Loadster Fuel Pricing
  • Monthly Plans

    Starting at $288 a month

    Run load tests whenever you need to without worrying about fuel usage. Test regularly at a straightforward monthly price.

    View Monthly Plan Pricing

Move fast
Don’t crash

Ready to reduce the risk of site crashes? Load test for the peace of mind that your site can handle it.

Start testing for free

Proud to be a load testing tool of choice for some pretty awesome people

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