I wrote about Gmail CSS support in 2016, quickly followed a few months later by an update following Gmail’s big responsive update. I tweeted another update in 2018. But I feel a proper article about it is long overdue. So here’s what I understand about Gmail CSS support that has changed since 2016.

What’s new

While there wasn’t a single update as big as the 2016 responsive update, Gmail’s updates have been adding up. Here are the three most significant updates of Gmail regarding HTML and CSS support.

Making sense of it all

Here’s an updated version of my diagram.