9 Oct 26 
Type is the interface for most sites. Here are the few levers that decide readability, from measure and line height to loading fonts without slowing the page.
UI Design
A few years ago I opened a portfolio site that stopped me dead. Full-bleed imagery, a custom display face, buttery scroll animations, the whole performance. Then I tried to actually read the about page and my eyes just slid off it. The body text was a thin grey weight, maybe thirteen pixels, stretched clean across a wide desktop so every line ran forever, with so little space between lines that the words felt stacked on top of each other. It was a beautiful site that nobody could comfortably read. I closed it in under a minute, and I have thought about it ever since, because it is the most common mistake I see and almost nobody treats it as a mistake.
Type is the interface
On most websites, text is not decoration on top of the product. Text is the product. The words are how someone decides whether to trust you, what you sell, what it costs, and whether to click the button. When I audit a page for a client, the single change that moves the needle most often is not a new hero image or a clever interaction. It is making the words easier to read. That is unglamorous work, and it is exactly why it gets skipped.
Readability beats cleverness every time, and the two are frequently in tension. A quirky condensed typeface set tight might photograph well in a case study, but it taxes the reader on every single line. There is real research behind the idea that things which look clean and effortless feel more trustworthy and easier to use, which I have written about in the aesthetic-usability effect. The trap is reading that as permission to prioritise looking good over being usable. The sites that win do both, and when they cannot, they choose the reader.
The few levers that actually matter
You do not need forty typographic decisions. You need about five, set well. Body size comes first. On the web I rarely go below sixteen pixels for body copy, and I am happy pushing to eighteen or more for long-form reading. Smaller than that and you are asking people to lean in, which they will not do. Then measure, the length of a line. Somewhere around sixty to seventy-five characters per line is the comfortable range. Past that the eye struggles to find the start of the next line, which is precisely what killed that portfolio page. You control measure with a max-width on your text container, not by hoping the viewport behaves.
Line height is the third lever. Body text usually wants something in the region of 1.5 to 1.6 times the font size, looser than designers instinctively set it, because generous spacing between lines does the same quiet work that whitespace does everywhere else on the page. Then contrast. That fashionable light grey text on a white background fails real people with real screens in real sunlight. I aim for genuine contrast and check it rather than trusting my eye on a nice monitor. Last comes hierarchy, a clear and limited set of sizes so a reader can tell a heading from a subheading from body at a glance, without three near-identical sizes that just read as noise.
Pairing, performance, and restraint
Pairing fonts is where enthusiasm turns into chaos. My honest default is one typeface, used across a range of weights and sizes. If I want two, I pick a pairing with obvious contrast of role, a characterful face for headings and a quiet workhorse for body, and I stop there. Two families, a sensible handful of weights. Every extra weight and style you load is another file the browser must fetch before the reader sees the text as you intended, and fonts are heavy. I subset to the characters I need, I lean on the formats and loading behaviour that let text show immediately in a fallback and swap in cleanly, and I treat a flash of readable fallback text as a feature, not a failure. Slow, invisible, or janky type is its own kind of unreadable, and every unnecessary weight adds to the load the reader carries, which ties into the broader argument I make about reducing cognitive load.
Responsive type deserves its own warning. The worst thing you can do on mobile is shrink the body text to make a layout fit. Phones are held closer, yes, but you still want a comfortable sixteen pixels or more. Scale your headings down on small screens by all means, but protect the body.
So before you reach for a new font or another animation, read your own page on a cheap phone in daylight. If the words are easy, you have done the hard part. Make the type kind to the reader first, and let the cleverness be the thing nobody has to work for.