[leftnode]

It's funny, I've been working with HTML since 1998, and I got 36 (though I do think <font> should've been allowed). I thought I'd do a lot better, but I guess you can accomplish a lot with only a few tags, CSS, and some minimal JavaScript.

[alberth]

I got to 41.

What helped is remembering an entire "block" of tags

e.g. H1 would also mean H2-H6

(I'll be the first to admit I really struggled to get to 41 and I too have been writing HTML by hand since 90s)

[taeric]

I struggled to get to 44.

Mildly curious on what all I'm not using.

[alberth]

https://eastmanreference.com/complete-list-of-html-tags

[taeric]

Apologies, I knew where and how to look them up. And, seeing the list, only a few I did not know. Some I couldn't remember the abbreviation used in the tag. I just didn't have enough curiosity to actually look them up. :D

[mediumsmart]

I got 40 without "div" and tried 4 invalid ones.

[breck]

Here's another good leet sheet: https://cheatsheets.zip/html

[dotancohen]

I got to 42 and forgot about font (and center, mentioned elsewhere). But quite a lot of tags weren't valid, such as marquee. I wonder if I broke 50 including those.

For what it's worth, I started writing HTML when dates began with the prefix 19... though most of my career has been on the server side.