What is the Optimal Text Length Per Line on Websites?

Building a website? It’s tempting to focus on flashy visuals and fancy features first. But something as simple as how long each line of text runs? That can seriously change how people read and interact with your site.

I mean, think about it. You don’t read a website the same way you do a book. Most folks scan, jump around, and only stick around if it feels easy on the eyes. So getting that line length right? It’s a big deal.

Let’s break it down in this blog post.

Why Does Line Length Even Matter?

Reading on screens isn’t like flipping through a paperback. On the web, people skim a lot more. If your lines are too short, the text feels jumpy, like someone’s chopping your sentences into bite-sized awkward bits.

But if lines stretch too long? Your eyes have to work overtime to find the start of the next line, and that’s just tiring.

Both extremes hurt how well someone understands what you’re saying. And worse, they might just click away.

The “Sweet Spot” for Line Length — What Science Says

Years of UX research, plus classic typography studies, point to a magic range: about 50 to 75 characters per line (spaces included).

Why? Because this range balances two things:

• Avoids too much horizontal eye movement that tires you out
• Keeps the reading flow smooth and focused

Jakob Nielsen, one of the legends in user experience, found that people read faster with slightly longer lines but prefer shorter ones because they look cleaner. So really, it’s about a trade-off between speed and comfort.

How Line Length Affects User Behavior

Let’s consider two options:

• Long lines (over 100 characters) require more horizontal eye movement and make it harder to locate the start of the next line. This slows reading speed and increases fatigue.
• Short lines (under 40 characters) break the rhythm of reading. The eye is forced to jump down more frequently, which disrupts comprehension.

When users struggle to read, they tend to skim which means they don’t get to consume the most important information. It could be your CTAs, your unique value proposition, or the services you offer. Or worse, they can leave the page entirely. As a result, this could mean lower engagement, decreased trust, and lost conversions.

How to Design for Optimal Line Length

Imagine reading a paragraph that stretches across a full-width desktop screen. Now compare that to the column of text in a newspaper or a blog which tends to be narrower. The latter feels easier, right?

Now, achieving the perfect line length isn’t that complicated. But what you want to remember that it’s all about smart, responsive design. Here are a few tips:

You don’t have to be a coding wizard to keep line length in check. Just a few simple tweaks do the trick:

• • Use CSS max-width to limit how wide your text can get, especially on big screens.

  • Stick with a font size around 16px–18px. Bigger fonts shorten lines naturally but don’t go too large or your design looks cramped.

  • Set line height between 1.5 and 1.6 times the font size for easy reading.

  • Add horizontal padding and margins inside text blocks to keep lines comfortable without wrecking your layout.

  • Break up long content with columns on wider screens — think two or three columns like a newspaper.

  • Avoid fully justified text; it creates weird spaces and makes lines look uneven, especially when they’re long.

  • Always test with real content — dummy text can fool you.

  • Use responsive breakpoints so your text doesn’t get too narrow on phones or too wide on desktops.

Here’s a quick snippet I use all the time:

…creates a readable, centered block of text that generally falls within the optimal 50–75 character range (depending on font).

Helpful Tools for Designers and Developers

Want to test your own site? Here are a few tools and tips:

• Browser Dev Tools: Use the inspector to check container widths and font sizes.
• Character Count Extensions: Add-ons like “Text Inspector” can show real-time character counts per line.
• Design Systems: Google’s Material Design and Bootstrap offer responsive typographic defaults that promote good readability.

Conclusion

The optimal text line length on websites isn’t just a design detail — it’s a usability essential. Staying within the 50–75 character range helps readers stay focused, improves comprehension, and enhances the overall experience of your site.

At Chromatix, a web design agency in Melbourne, we specialise in human-first web design that’s grounded in usability. That’s why, we’ve seen firsthand how small changes in content formatting, like adjusting line length, can improve time on site and readability metrics in website heatmaps and analytics. It’s a subtle, but powerful, design lever.

Give us a call today to start turning browsers into buyers, one readable line at a time.