For those who demand more than the occasional Lighthouse report

Track down-to-the-millisecond speed metrics for your real users, see the link between web performance and revenue, and get alerts to help you stay on top of it all. Built for people who take speed seriously.

No credit card required

Measure site speed for real users

Not everyone sees the same loading times for your site. People on faster devices and connections will have a better experience than others. Blackbird measures highly accurate speed metrics for your actual visitors, so you get the true picture.

Track your own custom metrics

Blackbird tracks modern frontend metrics like Largest Contentful Paint, but you can also set up your own custom metrics. So if you want to keep track of how long it takes for your first product image to load, for your logo to render, or anything else you can think of — you can.

Stay on top of site speed

Get email alerts if frontend speed metrics like First Contentful Paint or Largest Contentful Paint spike, so you can find and fix performance issues quickly.

Web Performance Alerts

Prove that speed is worth focusing on

Blackbird tracks highly accurate speed metrics and conversion data for your visitors, so it can help you prove that faster visits are more likely to convert.

Visits with a faster-than-average LCP are 25% more likely to convert, with a conversion rate of 4.41% vs 3.44% Data is statistically significant

Show the business the value of your work

Because Blackbird tracks site speed and conversion metrics from your actual users, it can work out how much extra revenue can be made from improving site speed. Now you can get buy-in from your team, build a performance culture and show the value of your work.

Based on the last 7 days, we've predicted how much additional revenue would be gained by improving Largest Contentful Paint by 500ms.

Each Week
+ £12,300
Each Month
+ £53,300
Each Year
+ £639,600

Try it for free today

Start your free 30 day trial - no credit card required

No credit card required

Common Questions

How does it work?

Blackbird is a lightweight tracking tag that you add to the site. It captures metrics like SSL connection time and Time To First Byte, as well as more frontend focused metrics like First Contentful Paint, Largest Contentful Paint and JavaScript CPU time - and it does this for your actual visitors, so you can a true picture of your page timings.

You also need to add a small piece of code on your Thank You page so that it can register that a user has converted, and what the order value was. This let's Blackbird tell you if faster visits have a better conversion rate, and tell you how much extra revenue could be made from making site speed improvements.

How does it track custom metrics?

If you use the User Timing API to set performance marks, Blackbird can automatically keep track of your own custom metrics. Once your performance marks are in place on your site, you can tell Blackbird which ones to keep track of, and it'll start tracking them automatically. If you want to know more, you can check out our guide on tracking custom metrics.

Does the tracking tag have a performance impact?

All JavaScript tags will have some impact, but we've worked hard to ensure ours has as small an impact as possible. It's less than 5kb, served from a CDN, and loads asynchronously. It's not on your critical path and won't delay rendering - and we also fully support deferring the tag, so it only has a minimal impact.

How is this different to Lighthouse?

Lighthouse is great - we love it. But it works by running one test, and tells you what your site speed metrics look like for just that one data point.

In reality your visitors will be on different devices, screen sizes, different connection speeds, in different locations - and will be seeing different site speeds as a result. One data point won't give you the full story when you have hundreds of thousands of visitors.

Blackbird tracks the site speed metrics for all of your visitors - down to the millisecond - so you'll have a much clearer picture of how fast your site really is.