At quick glance, it looks like they're still using the same CSS that was made public ~13 years ago:
https://github.com/wting/hackernews/blob/5a3296417d23d1ecc90...
Modern design trends are going backwards. Tons of spacing around everything, super low information density, designed for touch first (i.e. giant hit-targets), and tons of other things that were considered bad practice just ten years ago.
So HN has its quirks, but I'd take what it is over what most 20-something designers would turn it into. See old.reddit Vs. new.reddit or even their app.
perhaps try using a user agent that remembers your settings? e.g. firefox
To test, try setting your browser's font size larger or smaller and note which websites update and which do not. And besides helping to support different user preferences, it's very useful for accessibility.
[1] After testing, it looks like the "Reply" and "Help" links respect large browser font sizes.
None of the ”content needs white space and large fonts to breathe“ stuff or having to click to see a reply like on other sites. That just complicates interactions.
And I am posting this on an iPhone SE while my sight has started to degrade from age.
HN is the only site I have to increase the zoom level, and others below are doing the same thing as me. But it must be us with the issues. Obviously PG knew best in 2006 for decades to come.
16px is just massive.
HN has a good amount of white space. Much more would be too much, much less would be not enough.
1920x1080 24" screen here, .274mm pitch which is just about 100dpi. Standard text size in HN is also about 2mm across, measured by the simple method of holding a ruler up to the screen and guessing.
If you can't read this, you maybe need to get your eyes checked. It's likely you need reading glasses. The need for reading glasses kind of crept up on me because I either work on kind of Landrover-engine-scale components, or grain-of-sugar-scale components, the latter viewed down a binocular microscope on my SMD rework bench and the former big enough to see quite easily ;-)
On what devices (or browsers?) it renders "insanely small" for you? CSS pixels are not physical pixels, they're scaled to 1/96th of an inch on desktop computers, for smartphones etc. scaling takes into account the shorter typical distance between your eyes and the screen (to make the angular size roughly the same), so one CSS pixel can span multiple physical pixels on a high-PPI display. Font size specified in px should look the same on various devices. HN font size feels the same for me on my 32" 4k display (137 PPI), my 24" display with 94 PPI, and on my smartphone (416 PPI).
It has been changed since then for sure though. A couple of years ago the mobile experience was way worse than what it is today, so something has clearly changed. I think also some infamous "non-wrapping inline code" bug in the CSS was fixed, but can't remember if that was months, years or decades ago.
On another note, they're very receptive to emails, and if you have specific things you want fixed, and maybe even ideas on how to do in a good and proper way, you can email them (hn@ycombinator.com) and they'll respond relatively fast, either with a "thanks, good idea" or "probably not, here's why". That has been my experience at least.
On mobile it’s fine, on Mac with a Retina display it’s fine; the only one where it isn’t is a 4K display rendering at native resolution - for that, I have my browser set to 110% zoom, which is perfect for me.
So I have a workaround that’s trivial, but I can see the benefit of not needing to do that.
There is no such thing as a reasonable default size if we stop calibrating to physical dimensions. If you choose to use your phone at a scaling where what is supposed to be 1" is 0.75" then that's on you, not on the website to up the font size for everyone.
There's a trend to make fonts bigger but I never understood why. Do people really have trouble reading it?
I prefer seeing more information at the same time, when I used Discord (on PC), I even switched to IRC mode and made the font smaller so that more text would fit.
I'm not asking for some major, crazy redesign. 16px is the browser default and most websites aren't using tiny, small font sizes like 12px any longer.
The only reason HN is using it is because `pg` made it that in 2006, at a time when it was normal and made sense.
Maybe the issue is not scaling according to DPI?
OTOH, people with 30+ inch screens probably sit a bit further away to be able to see everything without moving their head so it makes sense that even sites which take DPI into account use larger fonts because it's not really about how large something is physically on the screen but about the angular size relative to the eye.
I don't really have to do the same elsewhere, so I think the 12px font might be just a bit too small for modern 4k devices.