38M browsers every day

500K concurrent users

Most popular news website in the UK

One of the most popular websites overall in the UK

One of the most popular websites in the world

BBC News

From Bangalore (India) on 3G

The Guardian

From Bangalore (India) on 3G

Identifying Performance Issues

Multivariate Testing

Remove blocking script from <head>

Page renders 1000ms sooner

Only download required CSS

Page renders 1000ms sooner

Don't include unused JS on the page

Page renders 200ms sooner

Load adverts asynchronously

Fixing the Issues

&

Measuring the Results

Async. Adverts

Global CDN

Lazy Load Images

Terminate TLS at Edge

Outstanding Issues

"The Hard Stuff"

765KB of JS

23 HTTP Requests

710KB of CSS

No "critical path" CSS

Technical Debt

BBC News Performance

By Joseph Wynn

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