Web Performance Optimisation, Consultancy, and Engineering

Trusted by:

Harry gave the team a strong footing for identifying performance issues on iPlayer. With his knowledge, we were able to roll out quick fixes to our audiences without the need for big rewrites, all within just two days.
Matthew Burrows, BBC iPlayer
Harry helped our team level up their scalable CSS architecture skills, and to say that he had a large impact on our work is an understatement. We can’t recommend him enough.
Addy Osmani, Google
Harry’s workshop was excellent; we left with tons of new ideas and techniques to improve both the CSS architecture and overall performance of Behance and Adobe Portfolio.
Jackie Balzer, Adobe
There’s a short list of people I whole-heartedly recommend for detailed performance work; Harry is right up there at the top.
Tim Kadlec
The CSS architecture I learned from Harry on the NHS project has changed the way I work. Bravo!
Josh Nesbitt

Web Performance and Site-Speed Insights

There are 239 articles on this blog. Find them all on the blog page.

29 February, 2012
Pragmatic, practical font sizing in CSS
12 February, 2012
Breaking Good Habits—The Digital Barn
11 December, 2011
On HTML and CSS best practices
7 December, 2011
Measuring and sizing UIs, 2011-style (and beyond)
8 November, 2011
Create a notched current-state nav
5 November, 2011
Build-along #1, reflection and reasoning
3 November, 2011
CSS Wizardry build-along #1
2 November, 2011
Sam Penrose Design—process and write-up
31 October, 2011
Fully fluid, responsive CSS carousel
27 October, 2011
The CSS Wizardry build-along is go!

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.

Connect

Projects

ITCSS – coming soon…

Next Appearance

Talk
Web Day Out: Brighton (England), March 2026

Learn:

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.

Start a Conversation

Audits

Consultancy

Training