About Harry Roberts – CSS Wizardry

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Hi, I’m Harry. I help teams understand how site-speed affects their business, improve Core Web Vitals, and find the real bottlenecks. I’m an independent web performance consultant based in Leeds, UK.
I’m an invited Google Developer Expert and Cloudinary Media Developer Expert. I’m also an international speaker and co-chair of performance.now(), a web performance conference for professionals.
Alongside my client work, I’ve published over 240 articles on CSS Wizardry. I’ve also delivered over 150 conference talks on web performance, site-speed, and front-end engineering. Since 2009, my writing and teaching have informed and improved the work of individuals and teams around the world. Heard enough?
I have many years of professional experience and have worked independently for more than a decade. Clients including the United Nations, Google, the BBC, General Electric, and many more have trusted me with their work.
My work sits somewhere between engineering, troubleshooting, and enablement. In practice, that means:
More often than not, it means some mixture of all three.
Through consultancy, performance audits, implementation support, and training, I help teams build faster, more resilient websites and stronger web performance practices around them.
There is a short list of people I whole-heartedly recommend for detailed performance work and Harry is right there at the top.
The two things I care most about are practicality and outcomes. Fast websites are good, but they aren’t an end in themselves. What matters is what that speed unlocks: better experiences, healthier conversion rates, stronger Core Web Vitals, and more confidence in the product itself.
I work with companies of all shapes and sizes, across a range of industries, countries, and team structures. The work might be a forensic performance audit, help fixing a specific issue, training for engineers, or a longer-term partnership. In a longer partnership, I help the team build performance thinking into the way it works. All of that is squarely in my wheelhouse.
If you need a faster website, better Core Web Vitals, a detailed performance audit, or a clearer understanding of your biggest opportunities, I can help. I’m comfortable in the weeds with engineers. I’m just as comfortable helping stakeholders understand the commercial side of web performance work.
If that sounds useful, say hello. I’m professional, but pretty laid back, and I’m always happy to see whether there’s a good fit.
CSS Wizardry uses tools and services that make my life as a developer much, much simpler.
I build CSS Wizardry with Jekyll, an open-source static site generator. GitHub Pages hosts the site, and Cloudflare serves it.
I write the CSS in Sass and build it on inuitcss. inuitcss is a free, open-source, Sass-based, object-oriented CSS (OOCSS) framework. It focuses on performance, scalability, and a small footprint. The site also uses ITCSS, a CSS architecture I created to help CSS projects grow and remain maintainable.
The site is intentionally fairly lean. It uses your system font to feel familiar and improve performance. SpeedCurve and Treo help keep CSS Wizardry fast.
The photograph used on the homepage’s masthead is of me speaking at Digital Labin, and was taken by Marin Cuk Vurnek of EVENTography.
You can view CSS Wizardry’s roadmap and task list on a public Trello board. You can also find all of the code that powers it on GitHub. Feel free to take a look round, but please don’t steal anything.
I chose the name CSS Wizardry when I was 17 years old. I had read Andy Budd’s CSS Mastery, become mildly obsessed, and then very unoriginally registered csswizardry.com.
I would not necessarily recommend letting teenagers pick their own domain names.
My early career really was rooted in CSS architecture and design systems, so the name made perfect sense for a long time. For the best part of a decade, my work has focused much more squarely on web performance. The name has stuck, and at this point I suspect it probably always will.
Hi there, I’m Harry Roberts. I am an award-winning Consultant Web Performance Engineer, designer, developer, writer, and speaker from the UK. I write, Tweet, speak, and share code about measuring and improving site-speed. You should hire me.
My secret blog: occasional notes on consulting, web performance, and the industry. For those in the know. Learn more…
I help teams achieve class-leading web performance, providing consultancy, guidance, and hands-on expertise.
I specialise in tackling complex, large-scale projects where speed, scalability, and reliability are critical to success.
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CSS Wizardry Ltd is a company registered in England and Wales. Company No. 08698093, VAT No. 170659396. License Information.