web.dev
Google's guidance on performance, accessibility and modern browser capability, including the full Learn CSS and Learn Accessibility courses. The reference for the metrics your site is actually measured against.
Guide
Web Development
Ongoing reference
Intermediate
Free
What it is
A publication covering web performance, accessibility, security and platform features, alongside several complete free courses including Learn CSS, Learn HTML, Learn Accessibility and Learn Performance.
Why performance guidance from here specifically
The Core Web Vitals metrics are defined here and they affect real outcomes, including search ranking. Guidance on how those metrics are measured, what actually moves them and which optimisations are theatre is more reliable from the source than from a tutorial repeating advice from three metric definitions ago.
The underrated part
Learn Accessibility. Accessibility is treated as an optional extra by a great many teams and is increasingly a legal requirement as well as an obvious good; this is a solid, free way to stop guessing.
Best for: front end developers responsible for performance or accessibility, which is most of them.
Ready to start?
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Stuck on something specific?
Writing only gets you so far. If you want an answer to your situation rather than the general case, book a session and we will work through it together. Every session is free; a few slots open each week.
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