Hi! I'm Simon, a web performance architect. I help my clients to deliver great web user experiences.
I write about web performance and speak about it at conferences. I also help to run the London Web Performance Group and an unfashionably grey QR Code generator.
It's something we've all felt before: the stress and anger induced when trying to use a frustratingly slow website or app. It's really hard to quantify this feeling though, and even harder to track it in your users.
There has been a lot of uncertainty and confusion since Google announced the Page Experience Update in 2020. With just over three months before the update goes live in May, here's what we know about it.
One of the biggest causes of layout shifts for my clients is late-loading web fonts, let's look at how to optimise them!
Speed is in the eye of the beholder, it is a perception of how fast an experience feels. Optimistic UI patterns can significantly improve perceived performance for relatively little effort.
Animated spinners are so 1999, there are some obvious and less-obvious alternatives to improve user experience.
2020 was a wild ride. Here are five key things to watch in the world of web performance in 2021!
Let's Encrypt will use its own root certificate in 2021, this may block access to 12% of Android users globally.
Extended Validation certificates are expensive and degrade performance. Move to an OV certificate if you can!
Getting fast is difficult, staying fast even more so. How do successful companies ensure that their site speed stays at peak?
Out of the hundreds of available performance metrics, which ones make sense for you?
Site speed is critical to user experience and online success, here are four charts which prove the value!
Core Web Vitals are three new performance metrics which will soon impact SEO ranking. Learn how to measure and improve them to maximise user experience!
We intuitively know that faster is better, but what's the psychology and physiology behind it?
Giving great software demos is both science and art. Here are some tips on making the most out of every demo opportunity, even when you're stuck at home!
A primer on save-data, what it means for your users and what it means for you.
Opting in to cookies can load multiple megabytes of additional content. Here are tips on how to measure web performance both with and without cookie consent.
We assume that browser caches are near-instantaneous, but data shows that retrieving an object from cache can take hundreds of milliseconds!
Web Performance is a niche term in a broad market, should we widen our appeal to reach more people?
How to collect data from your Home Automation system into a local timeseries database.
How to set up regular SpeedTest reports into a local InfluxDB on a Raspberry Pi
How to set up regular system stat reports from a Raspberry Pi into a local InfluxDB
I recently treated myself to a RaspberryPi 4 Model B to use as a(nother) home server. This is a brief guide on getting InfluxDB and Grafana set up to store and graph timeseries data.
An introduction to key HTTP response headers for speed and security, with implementation guides for Netlify & CloudFlare
Don't bet on 5G and HTTP/3 to make things faster, there are six technologies that I believe will have a bigger impact on web performance in 2020.
A deep-dive into the impact of third-party tags on web performance.
Native lazy loading for iframes and images landed in Chrome 76, but don't go ripping out your existing lazy loading strategy just yet.
A potential quick fix for "The test completed but there were no successful results." in WebPageTest private instances.
Site speed is a critical factor in the success of an online publishing business, whether revenue is driven by adverts or subscriptions. This post demonstrates the relationship between speed and publishing revenue, and suggests some quick wins to improve both!
Lead Developer is a conference for senior and lead software engineers. These are my raw notes from day one.
Delta V Conference is a new two-day, single-track web performance conference in London, hosted by me, Perry Dyball and Jo Franchetti. Here's my raw notes from the fantastic content from our lovely speakers on day two.
Delta V Conference is a new two-day, single-track web performance conference in London, hosted by me, Perry Dyball and Jo Franchetti. Here's my raw notes from the fantastic content from our lovely speakers on day one.
The Resource Timing API allows site owners to measure how third-parties perform for every single pageview. Combining this data with business intelligence provides new insight to the impact of third-party providers on business performance.
Twitter's Progressive Web App is finally out of testing, and it's not as good as the native app. Missing push notifications, wonky images, small text boxes, lack of sharing intents and confusing pull-to-update behaviour all highlight the challenge of building a PWA. The fact that Twitter is on-board with PWAs is a great step towards better web experiences...
You can't rely on your web analytics for performance data and it's understating bounce rate and traffic numbers from old devices.
Optimising sprites might be more important than you think, and easier than you expect!
Velocity Amsterdam has just come to a close. Here are the three key things that I am taking away from the two days of sessions.
Velocity New York seems like a distant memory now, especially with Velocity Europe around the corner. With that said, I have copious notes from the two day conference which I have summarised here. There were a lot of nuggets of wisdom which I’ll try to organise into a logical order.
We know that third-party content can harm the user experience on a website. Measuring that impact can be tricky.
Do you know when your website’s speed starts to impact your customers’ behaviour?
Tips to get more reliable & consistent visual metrics from WebPageTest
Render Conference - previously known as jQuery UK - was held in Oxford last week. It's a front-end conference for front-end people, which makes me a bit of an outsider. Performance is not the focus of Render Conference. Render is an opportunity for me to hone up my front-end skills and get an idea of what front-end developers are up against and the latest...
Sometimes prioritising recommendations is more important than making them.
This post is a review and summary of the talks at Velocity Europe that I attended. I've summarised each talk and given links to the slides, videos and ratings. A previous post contains the talks that got a five star review from me. Less than a five star review is not a bad thing, though. Five stars means exceptional, while three stars means the talk had s...
This post is a review and summary of the talks at Velocity Europe that got a 5 star review from me. I've summarised each talk and given links to the slides, videos and ratings. A further post contains the talks that didn't quite get a five star review from me.
Webpage jank can harm the user experience, here's an easy way to measure it on your pages
Modernizr might be making your site slow, especially on mobiles
Web performance is critically important, how will upcoming technologies change the way we manage it?
We need rules to keep third-party Javascript in check.
A feature to prevent cross-site-scripting may make it easier to police third-party javascript.
I've made a Heatmap to visualise when each element loads on a page.
Third-party means not you or me, but them.
Website performance is critical to user experience. We need rules to make it easier.
