Web Typography Guide: Font Sizes, Line-Height, and Readability

Typography on the web is not just an aesthetic choice, but the foundation of readability and visual structure on any screen. Set the font sizes, line height, and contrast correctly, and users will navigate your text effortlessly. In practice, technical details make the difference between a tiring website and a professional, easy-to-read digital experience.

What is the recommended minimum font size for body text on a website?

The minimum recommended font size for body text on a modern website is 16px, but the ideal size for long articles is 18px or even 20px. Using relative units, such as rem, guarantees that the text adapts to the user's browser preferences, where 1rem equals 16px by default. Text smaller than 14px should be reserved exclusively for secondary elements, such as footnotes, tags, or dates. On mobile screens, a 16px base text also prevents unwanted automatic zooming in input fields on iOS. Font sizes that are too small cause users to leave the page quickly due to increased visual strain.

How do I correctly calculate typographic hierarchy and heading sizes?

Typographic hierarchy is most easily calculated using a modular scale, where each heading level is multiplied by a constant ratio, such as 1.25 (Major Third) or 1.333 (Perfect Fourth). If the base text is 16px, applying a 1.25 ratio creates proportional and harmonious sizes across all page elements:

• H1 (Main Heading): 39px – 48px (used once per page for visual impact and SEO structure).
• H2 (Section Heading): 31px – 38px (separates major content topics).
• H3 (Subheading): 25px – 30px (organizes subsections within an H2).
• H4-H6 (Details/Cards): 18px – 20px (for small UI components or card titles).
• Body Copy: 16px – 18px (standard text for effortless reading).

This mathematical proportion removes guesswork and provides clear visual order for the user.

What is line-height and what value should I use for readable text?

For easily readable body text, the optimal line-height value is between 1.5 and 1.6 (or 150%-160% of font size), specified without fixed measurement units. For large headings like H1 or H2, where the font is over 32px, the line height should be reduced to 1.1–1.3 to prevent excessive spacing between lines. Using a unitless value (e.g., line-height: 1.5 instead of line-height: 24px) is essential in CSS because it enables automatic proportional calculation when font size changes across smaller screens. Too tight line height crowds the lines and tires the eye, while too large values break paragraph cohesion.

How many words or characters should be on a line of text for desktop and mobile?

The optimal line length for comfortable reading on desktop is between 45 and 75 characters (including spaces), with the ideal target being around 66 characters. If a line is too long, the reader's eye struggles to locate the start of the next line. If it is too short, the reading rhythm is constantly broken. In CSS, you can constrain text container width using the ch unit (for example, max-width: 65ch;). On mobile devices with restricted screen widths, character count naturally decreases to 35–45 characters per line, which remains completely acceptable when side padding is properly configured.

How does font choice affect readability and website loading speed?

Your choice of font directly impacts readability through character design and page speed through the number of files downloaded by the browser. When I build an effective site de prezentare, I recommend limiting fonts to maximum 2 font families and loading no more than 3-4 weights (such as Regular, Medium, Bold). Every additional font file adds extra kilobytes to download times. Professional design grafic services prioritize web-optimized formats (WOFF2) and use the CSS font-display: swap property to render system fonts immediately until custom fonts load, preventing invisible text issues.

What contrast ratio and colors are required for readable text?

The minimum contrast ratio required by international WCAG 2.1 AA standards is 4.5:1 for normal text and 3:1 for large text (above 24px). Avoid using pure black (#000000) on a pure white background (#FFFFFF), as it creates an overly harsh contrast that leads to eye fatigue. Instead, use dark gray shades like #1A1A1A or #222222 on white or off-white (#FAFAFA) backgrounds. Light gray text on white backgrounds should be avoided entirely, as it is unreadable for visually impaired users or screens exposed to bright sunlight.

How do I adapt typography for mobile devices (fluid typography)?

Fluid typography is best implemented using the CSS clamp() function, which allows font sizes to scale fluidly between a minimum and maximum threshold based on screen width. This technique eliminates the need for dozens of rigid media queries across various mobile breakpoints.

Practical rules for mobile typography adaptation:

• Use clamp(): Syntax like font-size: clamp(1rem, 2.5vw, 1.5rem) ensures smooth font scaling.
• Adequate touch area: Text links and buttons should feature a minimum touch target size of 44x44px.
• Sufficient side margins: Keep at least 16px-20px padding at screen edges to prevent text from touching screen borders.
• Test on small displays: Always verify readability on smartphones starting from 360px width.

In my identitate vizuala projects, I establish clear screen typography rules, and when implementing geo-aeo-aio optimization strategies, structured readability helps search engines and AI systems extract information accurately.

How does typography impact user experience and conversion rates?

Optimized typography increases conversion rates by reducing cognitive load and directing visual attention toward key page actions. Unreadable or poorly structured text increases bounce rates within seconds, regardless of how strong your value proposition is. When reviewing a project from my portofoliu, you will notice how proper spacing, clear contrast, and defined hierarchy make CTA buttons and forms stand out immediately. Web users scan content; flawless typography provides visual anchor points that pause scanning on key business benefits.

What's next?

If your current website suffers from poor readability, small font sizes, or a cluttered visual layout, it is time for a professional typographic optimization. A careful review of font sizes, line heights, and CSS code can dramatically improve user experience and online performance. If you want to build a fast, accessible, and visually striking website, visit the contact page to discuss your project. We will evaluate your current layout and implement web design best practices tailored to your brand.