Free Website Speed Test

Check your site's performance, page load time, and Core Web Vitals from a real Chrome browser in a location of your choice.

Why run a website speed test? Every millisecond counts to your users.

Page load speed is one of those things that affects almost everything else about your site. Your search ranking, conversion rate, bounce rate, ad cost, and brand perception, to name a few. Google uses Core Web Vitals as a search ranking signal, so a slow LCP can quietly cost you visibility before a single user ever notices. Web performance studies have shown that every extra 100 ms of load time shaves a measurable amount off of your conversion rates.

Site speed is also where front-end and back-end performance meet. A slow database query could surface as a sluggish TTFB. A bloated JavaScript bundle pushes out FCP. A misconfigured CDN turns into a long redirect chain. Determining what makes your site slow is critical to fixing it.

A single speed test gives you multiple timing numbers and a detailed waterfall of requests and responses, so you can tell where in the stack to start digging in.

If you're new to the topic, Loadster's guide on front-end vs back-end performance is a good place to read more.

Web performance is multidimensional. Measure the metrics that matter.

Start with this free speed test, and Loadster will load your URL in a real Chrome browser running on a cloud engine to capture the most important browser performance signals.

Loadster's speed test uses the browser's Performance API to gather the following metrics:

Time to First Byte

How long the server took to start responding. High TTFB usually means slow application code, slow database queries, or a long network path.

First Contentful Paint

The moment something visible first appears. The CLS is largely driven by TTFB as well as frontend render-blocking CSS and JavaScript.

Largest Contentful Paint

When the largest above-the-fold element finishes painting. Google uses this as a Core Web Vital. Under 2.5 seconds is the worst-case target.

Cumulative Layout Shift

How much the page jumps around as it loads. High CLS is caused by images without dimensions, late-loading fonts, or injected ads.

Total Page Load Time

The full wall-clock time from navigation start until the load event firing. This is basically when your browser's spinner stops.

Resource Timings

Every resource the page fetched, with start time, duration, status, and size. The fastest way to spot a slow third-party resource.

Loadster's free speed test runs a single page load at a time. That's perfect for a performance baseline, but it's no substitute for measuring how the site behaves under concurrent traffic.

Chances are, your site's performance won't be the same under minimal load (a single user) as it is in a traffic spike or heavy traffic event. That's where load and stress testing become important.

Website speed tests, load tests, and stress tests... what's the difference?

These three terms sometimes get thrown around interchangeably, but they answer different questions.

Speed Testing

A single visitor loads a page. Measuring your site's baseline performance under minimal load is a starting point.

Load Testing

Many simulated visitors load the site concurrently to confirm it holds up under expected peak traffic levels.

Stress Testing

Ramp the concurrent traffic up until something gives, to find the breaking point and see how the system fails.

Keep in mind, a site can score great on a baseline speed test and still crash under load! The opposite also happens: a site optimized for throughput can still have an embarrassingly slow first paint, meaning you should probably focus on frontend optimizations.

For a deeper dive, check out our guides on load testing vs. stress testing and website load testing.

Load Test Your Site

Your site's performance can change over time. Monitor it 24/7 with bots.

Your site speed can change over time, especially as you make changes to the site content and infrastructure.

A site that scored a 1.8 s LCP at 10 am can score 4.2 s at 8 pm because a third-party analytics tag started timing out. A site that's fast from London can be slow from Singapore because the CDN edge there is misconfigured. A site that's been fast for months can suddenly slow down because somebody on your team pushed an unminified bundle.

A one-off speed test is the obvious place to start. Ongoing monitoring is what you need for everything else. Catch the regressions that only appear at certain times of day, the regional slowness you don't see from your office, the slow third-party that creeps in after a marketing tag manager push.

Most teams use a speed test to find the first problem and monitoring to make sure it doesn't quietly come back.

Set Up Site Monitoring

Frequently Asked Questions

How is this different from PageSpeed Insights or Lighthouse?

PageSpeed Insights and Lighthouse run a synthetic test from Google’s infrastructure and weight the result through their own scoring model. This speed test runs a real Chrome browser from a cloud region you pick, returns the raw timings (TTFB, FCP, LCP, CLS) plus the full request waterfall and response headers. It’s useful when you want more underlying data and not just a score.

Is it really free? Do I need to sign up?

Yes, the free speed test is totally free. No signup, credit card, or email required. Just submit a URL and the test runs. If you later want to run concurrent load tests or site monitoring, you can create a Loadster account for that.

What's the difference between a speed test and a load test?

A speed test loads your site once, with a single browser, and reports how long that single page load took. A load test sends many concurrent users to your site at the same time to see how it performs under traffic. Both are useful for different reasons. A fast site for one visitor can still collapse under load.

Why pick a region?

Web performance varies a lot by where the request comes from. A site hosted on us-east-1 might feel snappy from Virginia and sluggish from Sydney. Running the speed test from different regions tells you whether the slowness is the site itself or the network distance to a specific market.

What do TTFB, FCP, LCP, and CLS actually mean?

TTFB (Time to First Byte) is how long until the server returns the first byte. FCP (First Contentful Paint) is when something visible first appears. LCP (Largest Contentful Paint) is when the largest above-the-fold element finishes painting. CLS (Cumulative Layout Shift) measures how much the page jumps around as it loads. Lower is better.

Should I run one-off speed tests or set up monitoring?

Both, ideally! A one-off speed test is great for spot checks and baseline frontend performance optimization. Monitoring runs the same script on a schedule from multiple regions, so you catch regressions that might show up at 3am or only from a specific country. Most teams use the speed test to find a problem and monitoring to make sure it doesn’t come back.