Site-Speed Optimisation – Web Performance and Site Speed Consultant

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

Articles

There are 249 articles on this blog. Find them all on the blog page.

12 October, 2022
Speeding Up Async Snippets
6 September, 2022
Critical CSS? Not So Fast!
24 August, 2022
Measure What You Impact, Not What You Influence
28 March, 2022
Optimising Largest Contentful Paint
26 February, 2021
Measuring Web Performance in Mobile Safari
3 November, 2020
Site-Speed Topography
19 May, 2020
Speed Up Google Fonts
22 April, 2020
Real-World Effectiveness of Brotli
8 January, 2020
Performance Budgets, Pragmatically
15 August, 2019
Lazy Pre-Browsing with Prefetch

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.

Suffering? Fix It Fast!

Connect

Projects

ITCSS – coming soon…

Next Appearance

Talk
Devoxx Greece: Athens (Greece), April 2025

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

.site-nav__list { content-visibility: visible; }

Audits

Consultancy

Training