What’s so special about Performance Analyser?

If you want detailed, accurate insight into how your website’s performing, Performance Analyser, our real-browser testing and analysis tool, is an excellent way to get the answers you need. You can run single page tests or crawls in a number of real browsers, as well as schedule regular tests.

I’ve been working on Performance Analyser for some time now, and I thought I’d run through a few of the things that I think make it a bit special.

Why now?

Performance Analyser has been around for a while, but in the past year or so, we’ve made a concerted effort to up our game. We’re now putting some finishing touches on a series of updates that turn it into a very different product.

Before we move on to the latest upgrades, let’s take a quick look at the foundations that Performance Analyser is built on.


At NCC Group, we’re positively obsessed with accuracy. For us, there’s no point in testing at all if you can’t expect consistent, accurate, reliable results. This is why some of Performance Analyser’s biggest strengths are in the platform we have built around it. We have invested a lot of time, money and engineering into producing a platform that can measure differences in performance accurately. These differences can be about changes over time (for example, over peak periods or in relation to the release cycle). Or they could be about how your website compares with your key competitors.

We also spend a lot of time managing and maintaining the platform to retain this level of consistency. Agents are regularly rebuilt and ‘reverted’ to ensure they aren’t affected by the contamination so often seen with Windows desktops/browsers. In addition, we use (customisable) throttled network connections, provisioned over a high-quality network infrastructure to ensure performance changes are not due to ‘random’ network contention. We also manage platform capacity to reduce queue times, so that results come back quickly.

However, there’s much more to Performance Analyser than reliable testing, so let’s look at some of the new features.

Mapping requests from different domains

The latest addition is the Request Map. This gives you an overview of all the domains used to serve content on a web page and is one of two features initially developed by senior technical consultant Simon Hearne. The Request Map also draws on a database that puts each domain in a category, such as advertising or analytics (a database that’s constantly being updated and refined).


The Request Map is particularly useful when it comes to understanding the volume and impact of third-party content on a page. So many sites (especially in retail and publishing) now include so much content from domains outside the direct control of the site owner that it’s often hard to keep track. The Request Map is a really helpful way to visualise the relationship between all the domains that contribute to a page, and we’ve already found it very useful in our Third-Party Tag Reviews. Note that while you can generate a Request Map for a test run in any browser, you’ll get the best results from Chrome.

Visual performance and performance visualisations

There was a time when performance was all about how long it took a page to finish loading. Now, although overall load times still matter, we’re increasingly interested in visual performance. That’s why we’ve added metrics such as visually complete and Speed Index (which measures the rate at which a page becomes visually complete above the fold).

More recently, we’ve added the Performance Heatmap which, like the Request Map, was developed by Simon Hearne. The Request Map uses a red-amber-green overlay to show which parts of a page are slow or fast to render. This allows you to check whether different elements on a page are meeting key performance indicators (KPIs). For example, a page might have to deliver a hero image within a certain timeframe.


Customising tests

Much of our recent work on Performance Analyser has been designed to enhance its flexibility.

Scripted sessions, for example, mean that tests can involve complex interactions with websites and span multiple pages. So it’s now possible to test pages that sit behind a login or to get Performance Analyser to scroll down a page and click a button that triggers an AJAX response. Currently, scripting in Performance Analyser is available only as part of a managed service, so if you need to run some tests that involve interacting with a web page, just let us know!

However, there are also several additional out-of-the-box settings that you can now use to fine-tune your Performance Analyser tests.

For example, you can now adjust download speed, upload speed, packet loss and latency. Once you’ve settled on your preferred network conditions for testing, you can set this as your default (read more about this updatehere).

There is also now a device profiles feature that allows you to emulate a range of mobile phones and tablets – perfect for testing responsive and adaptive sites.

Continuous integration

One popular use for Performance Analyser is to address site performance as part of the release process (with scripted sessions making it easier to test development environments). Since many of our customers use continuous integration solutions, such as Jenkins, we’ve developed the PA Runner for Continuous Integration: a convenient way to build Performance Analyser tests into the process. Note that this is an open source solution rather than an officially supported product, but several customers have found it helpful.

HTTP/2 support

Is your site HTTP/2 ready? HTTP/2 adoption is growing, and features such multiplexing, server push and header compression should help make the web faster. As part of our latest round of browser updates, Performance Analyser tests in Chrome and Firefox will now automatically load web pages using HTTP/2 wherever possible.

A new look

Last but not least is the facelift we’ve recently given Performance Analyser. We’re gradually working towards the point where all our products share the same look and feel (if you’ve tried the new interface for our monitoring service or signed up for a trial of our new real user monitoring product, you’ll know what I mean). Customers using more than one product should now find it much less jarring as they switch between them. At NCC Group Web Performance, we’ve always been known for the quality of our data more than the attractiveness of our user interfaces. However, over the last couple of years we’ve come to realise that both are important, and we’re now making serious improvements.

If you’re already using Performance Analyser, you’ll hopefully find that these changes make it more flexible, easier to use and ultimately more valuable. If you haven’t tried Performance Analyser, you can find out more here.

Paul Bianciardi

Paul BianciardiAs a Technical Solutions Architect at NCC Group Web Performance, Paul’s days are always full of variety.

He is involved with many aspects of our delivery, from the technical implementation of new features and products to helping customers with specific problems.

Prior to joining NCC Group in 2009, Paul was one of our customers, which gives him a real appreciation of the importance our products and solutions.

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