Adding site search to Netlify sites using Elasticsearch 🔗
Static site generators (SSGs) such as 11ty allow us to build super-fast websites with great developer experience. Hosting platforms like Netlify allow [...]
Simon Hearne
Posts
Optimising Core Web Vitals on SPAs 🔗
Approximately 40% of my clients have single-page applications (SPAs), and approximately 100% of my clients care about core web vitals - the key perfor [...]
Fixing empty responses from Cloudflare Workers Sites 🔗
I'm currently working on a client project using Cloudflare Workers Sites. Mostly development has been a joy, the wrangler CLI is easy to use and produ [...]
Survivorship Bias in Web Performance 🔗
Introduction # Way back in 2010, an engineer at YouTube kicked off Project Feather: the goal was to reduce the weight of the popular video player page [...]
The value of an independent web performance consultant 🔗
I have been employed in web performance roles for about a decade. From load testing and synthetic monitoring to CDN configuration and true consultancy [...]
Caching Header Best Practices 🔗
Introduction # Caching headers are one of those deceptively complex web technologies which are so often overlooked or misconfigured. The fastest reque [...]
Fast and Responsive Hero Videos for Great UX 🔗
Landing page hero videos are increasingly popular, especially in high fashion and luxury goods. Hero videos can have a detrimental effect on user expe [...]
An Inclusive Web is Fast by Default 🔗
View Slides [...]
Slow site speed is still the biggest cause of web stress 🔗
Back in 2010 Foviance ran an EEG study [1] which showed that participants had to concentrate 50% harder when websites were slow, as measured by alpha [...]
Everything we know about Core Web Vitals and SEO 🔗
June 15th 2021: Multiple updates from Google I/O 2021, a Web Vitals Q&A session and another Google blog post. April 19th 2021: Google have announced [...]
How to avoid layout shifts caused by web fonts 🔗
One of the outcomes of the release of Core Web Vitals (and subsequent inclusion in Google's page ranking algorithm) is that we have been paying more a [...]
Optimistic UI Patterns for Improved Perceived Performance 🔗
Introduction # Web performance is often seen as a technical discipline, arranging bits and bytes to shave off milliseconds of load time, applying best [...]
Alternatives to Spinners on the Web 🔗
Animated spinners are one of the lingering legacies of the 1990's web. In this post I will use an insurance quote service as an example, but these tec [...]
Web Performance Predictions for 2021 🔗
I wrote an article in 2019 where I predicted five top technologies for 2020. Well, 2020 was a strange year! Some things were correct though, for examp [...]
The Impact of Let's Encrypt Changes on Android Users 🔗
Let's Encrypt recently announced that it is moving to using its own root certificate on January 11, 2021. This will reduce operating costs and complex [...]
The Performance Cost of EV Certificates 🔗
Introduction # Extended Validation or EV Certificates were once prized for their impression of increased security. Sites with an EV certificate would [...]
Getting Fast and Staying There 🔗
If you've ever trained for a big sporting event: a marathon, bike race or similar, you'll know how tough it is to train to get to your peak performanc [...]
What is the best page speed metric? 🔗
The recent updates from Google on Core Web Vitals are a great effort to find universal speed metrics that reflect quality of user experience. Google's [...]
Four Charts That Prove the Value of Site Speed 🔗
Site speed is an important but often-overlooked component in user experience. We know intuitively that slow experiences are unpleasant and make us mor [...]
How to Improve Core Web Vitals 🔗
10 Nov update: Google has announced that the Page Experience update will go live in May 2021! Introduction # Google announced updates to the Page Exp [...]
The Psychology of Speed 🔗
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Giving Great (Remote) Software Demos 🔗
Introduction # I've been in technical pre-sales for about ten years, and software demos have been a part of my role since day one. I'm still working o [...]
Who Opts-in to Save-data? 🔗
In Summary # Save-data is a client hint which indicates that your users want you to send less content to them. It is an option on Google Chrome Mobile [...]
Measuring Performance behind consent popups 🔗
Introduction # Cookie consent has given users control over the data that is shared with websites and third-parties, but it has made measuring performa [...]
When Network is Faster than Cache 🔗
Introduction # I recently discovered that Firefox introduced a feature called RCWN (Race Cache With Network) in 2017. This feature was intended to imp [...]
Is it time for a Web Performance rebrand? 🔗
Web performance has been a hot topic in web development and browser engineering since the first public web pages. The first book on the topic, Web Per [...]
Collecting SmartThings data in InfluxDB on Raspberry Pi 🔗
Now that you've got your Pi set up with Influx & Grafana, you're collecting some system stats, and measuring network performance, it's time to collect [...]
Collecting SpeedTest results in Influx on Raspberry Pi 🔗
Now that you've got your Pi set up with Influx & Grafana and you're collecting some system stats, it's time to measure network performance! SpeedTest. [...]
Reporting Raspberry Pi System Metrics to InfluxDB 🔗
Now that you've got your Pi set up with Influx & Grafana, it's time to start collecting some data! We will use a simple Python script to collect syste [...]
Installing InfluxDB & Grafana on Raspberry Pi 🔗
Step 0: Initial Setup # Follow these steps first if you have a brand new rPi: Download the latest lite Raspbian image from raspberrypi.org Get a reaso [...]
HTTP Headers for fast & secure static sites 🔗
This website is powered by Netlify, it also has Content-Security-Policy and cache-control HTTP response headers to improve client security and perform [...]
Six Web Performance Technologies to Watch in 2020 🔗
Introduction # Reading the technical press you would be forgiven for thinking that 2020 is going to be a great year for web performance. Repeatedly to [...]
Deep dive into third-party performance 🔗
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Native image lazy loading has landed in Chrome, maybe don't use it 🔗
Lazy Loading Images # Web browsers are complex pieces of software, but still treat images relatively naïvely. See, for example, a section of this wate [...]
WebPageTest Private - 'no successful results' 🔗
I recently configured a new private WebPageTest instance on AWS to use SSL provided by Let's Encrypt, using EFF's awesome CertBot. When running my fir [...]
Why Site Speed is Critical for Online Publishers 🔗
It has been well documented that site speed is a major factor in business success for e-commerce websites. If you can demonstrate that improving page [...]
Lead Developer Conference (London) - Day 1! 🔗
Alice Goldfuss - The Container Operator’s Manual # Containers are generally presented in theory, Alice tells us how they work in real-life. Alice is a [...]
Delta V Conference - Day 2! 🔗
Tammy Everts - Hunting the Unicorn # Tammy started researching user experience on the web in a laboratory setting - measuring individuals as they used [...]
Delta V Conference - Day 1! 🔗
Tim Kadlec - Redefining Web Performance # There is a lot of under-appreciated creativity in technical work. Definitions change - dictionaries are out [...]
Third-Party Content - the weak link? 🔗
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Twitter Lite isn't as good as the app, and that's okay 🔗
The promise of PWAs # Progressive Web Apps bring a native-like application experience to websites. This is achieved through a combination of specifica [...]
Your Analytics Lies to You 🔗
The site speed fallacy # In a recent webinar, Andy Davies and I asked a poll of the attendees: where do you get your site speed data? Bear in mind tha [...]
How to Optimise CSS Image Sprites 🔗
CSS image sprites can provide a performance benefit for most sites. A sprite combines multiple small images into one file and CSS slices out the relev [...]
Three WebPerf Takeaways from Velocity Europe 🔗
1) Performance KPIs are broken # This was one of the themes that ran like an undercurrent through the whole conference, starting with Steve Souders at [...]
Velocity NY 2016 - Wrap-up 🔗
(p.s., the video of my talk on performance for low powered devices is up!) Real User Monitoring is getting exciting, but has gaps # Everyone is using [...]
Blocking requests in webpagetest? Don't use Chrome. 🔗
Note: this issue has since been resolved by the Chrome team, please proceed with caution! TL;DR: Blocking third-party requests in webpagetest shows y [...]
How fast is fast enough? 🔗
Do you know when your website's speed starts to impact your customers' behaviour? The speed of your site affects how your visitors behave: how many pa [...]
Getting Reliable Visual Performance Metrics 🔗
Visual metrics such as Speed Index, render start and visual complete are the best proxies we have for user experience. Unfortunately two of these are [...]
Render Conf 2016 🔗
Bruce Lawson - web.next # Description | Slides | Video # I had assumed that Bruce's talk would be identical to the last few I've seen. Bruce's previou [...]
Prioritising Site Speed Recommendations 🔗
One of my favourite tasks as a consultant is to provide reports to clients which make recommendations for improving site speed. Often these reports ar [...]
Velocity Europe 2015 - The Good Ones! 🔗
Another post lists the talks that got five stars from me! Continuous Performance - Stijn Polfliet (CoScale) # Description | Video (5m) | Slides (ppt) [...]
Velocity Europe 2015 - My Allstars 🔗
Another post lists the talks that didn't quite get five stars from me! The Physical Web is a Speed Issue - Scott Jenson (Google) # Description | Video [...]
Measuring Webpage Jank 🔗
Here's the bookmarklet: =0;n--)try{document.body.removeChild(e[n])}catch(r){continue}var r=document.getElementById("fpser");r&&r.parentNode.removeChil [...]
Be Mindful With Modernizr 🔗
According to Modernizr.com, Modernizr is a JavaScript library that detects HTML5 and CSS3 features in the user's browser. This framework tests for fea [...]
The Future of Web Performance - Part 1 🔗
Web performance is critical to a successful online business. Keeping on top of the latest technologies, techniques and practices allow us to stay ahea [...]
Questions to Ask Your Third-Parties 🔗
We've discussed how to find the third-party assets on your site and started to look at how to mitigate the risk that they pose. But what should you do [...]
Manage Third-party Risk Using a Content Security Policy 🔗
Andy Davies and I have spoken at a number of conferences about the risks that third-party components can have on your website. In these talks we try t [...]
Using a Web Performance Heatmap to Assess Page Performance 🔗
Go to the tool I've recently had a few clients ask if there is a way to test when certain parts of their pages become visually complete. Imagine a med [...]
How to Find the Third-Parties on Your Site 🔗
Go to the tool My customers often ask how a third-party asset got on their site. A director of digital once told me that Facebook was not on their sit [...]
Web Performance Optimisation Basics 🔗
Our web performance industry was unquestionably seeded by Steve Souders' book High Performance Websites. In his book, steve identifies 14 rules to imp [...]