Anthony Ricaud (@anthony_ricaud) is a web engineer helping teams ship efficient products at a sustainable pace. With a broad understanding of web protocols and browsers, he likes to design simple but fast web architectures. Longer page load times Page is unusable until the JavaScript loads and if it does so without any errors Usability, reactivity and accessibility can be lacking without a team wi

Peter Hedenskog (@soulislove) loves Open Source and really cares about the open web. Peter is one of the creators of the Open Source sitespeed.io web performance tools. I hope you didn’t miss the session about The Future Of Core Web Vitals at Chrome Dev Summit 2020. I think it’s great that the Chrome team is open about the metrics and is looking for feedback! When Google Web Vitals first was intro

Robin Marx is a Web Performance and network protocol researcher at Hasselt University, Belgium. He is mainly looking into HTTP/3 and QUIC performance, and develops the qlog and qvis tools to make this easier. In a previous life he was a multiplayer game programmer and co-founder of LuGus Studios. YouTube videos of Robin are either humoristic technical talks or him hitting other people with longswo

Matt Hobbs (@TheRealNooshu) is Head of Frontend Development at the Government Digital Service. An experienced frontend developer, he is passionate about using his skills to build accessible and performant user interfaces. Matt makes a point of keeping on top of the latest technology and tools, is interested in all aspects of interface development, and is a keen advocate for best practices. In this

The results basically confirmed my hypothesis, 55% SVG, and PNG + GIF brings the percentage of these three file types to 93%. What did surprise me was that the remaining 7% are nearly all fonts. What are the tonnage costs of these files? We can calculate the length of each of these files (this is uncompressed, and in bytes), and graph the percentiles: Looking carefully at this chart, there are 3 l

Katie Hempenius (@katiehempenius) is an engineer at Google where she works on web performance. Prefetching is a technique that can be used to achieve near-instant page loads. This technique has been used for decades to speed up hardware and compilers; but it’s only been recently, thanks to the introduction of the Network Information API, that it’s usage to speed up web applications has become prac

Tobias Baldauf (@tbaldauf) helps to keep trivago fast. He creates DevOps tools, image optimization algorithms & speaks at conferences. He's a proud dad, mindful veggy & music lover. Find out more at who.tobias.is tl;dr: JPEG-XR, an image format supported on Internet Explorer and Microsoft Edge browser, gets software-decoded on the CPU main thread alongside Javascript and thereby negatively impacts

Robin Marx is a Web Performance PhD candidate at Hasselt University, Belgium. He is mainly looking into HTTP/2 and QUIC performance, and maintains the TypeScript QUIC implementation Quicker. In a previous life he was a multiplayer game programmer and co-founder of LuGus Studios. YouTube videos of Robin are either humoristic technical talks or him hitting other people with longswords. QUIC and HTTP

Rick Viscomi (@rick_viscomi) is a web performance engineer and developer advocate at Google working on web transparency and the HTTP Archive. In a previous life he also helped make YouTube fast and coauthored the book Using WebPageTest. There are many case studies documenting how web performance and business metrics like conversion rates and ad revenue are correlated. But when a website is slow, t

Andrew Betts (@triblondon) is a web developer and principal developer advocate for Fastly, working with developers across the world to help make the web faster, more secure, more reliable and easier to work with. He founded a web consultancy which was ultimately acquired by the Financial Times, led the team that created the FT's pioneering HTML5 web app, and founded the FT's Labs division. He is a

Tobias Baldauf (@tbaldauf) leads the Core Frontend team at trivago. He creates DevOps tools, image optimization algorithms & speaks at conferences. He's a proud dad, mindful veggy & music lover. Find out more at who.tobias.is tl;dr:Image placeholders in SVG are ready for prime time thanks to browser support and good rendering performance. By automating SVG shape creation that mimics main features

Colin Bendell is a performance and ideas junkie. He is co-author of O'Reilly's High Performance Images and part of the CTO Office at Cloudinary. tl;dr GIFs are awesome but terrible for quality and performance Replacing GIFs with <video> is better but has perf. drawbacks: not preloaded, uses range requests Now you can <img src=".mp4">s in Safari Technology Preview Early results show mp4s in <img> t

Peter Hedenskog (@soulislove) works in the performance team at the Wikimedia Foundation. Together with Tobias Lidskog and Jonathan Lee, they are the core team of sitespeed.io. At the Wikimedia Foundation we’ve been working on finding web performance regressions for a couple of years. We are slowly getting more confident in our metrics and find regressions easier. Today I wanna show you how we auto