Readable Typography

TL;DR

Technical UX issues can prevent crawlers and users from reliably accessing or consuming your content. Fix performance, responsiveness, HTTPS/mixed content issues, and intrusive UX blockers. Use Oversearch AI Page Optimizer to rescan and confirm technical quality improves.

Why this matters

Technical quality impacts both crawling and user satisfaction. Performance, HTTPS, mobile, and intrusive UX can block access and reduce engagement.

Where this shows up in Oversearch

In Oversearch, open AI Page Optimizer and run a scan for the affected page. Then open Benchmark Breakdown to see evidence, and use the View guide link to jump back here when needed.

Does font size and contrast affect SEO?

Indirectly yes. Poor typography increases bounce rate and fails accessibility checks, both of which can affect rankings through user experience signals.

Google’s page experience signals include mobile usability, which checks for readable text size. Low contrast and small fonts also fail WCAG accessibility requirements.

• Body text should be at least 16px on mobile.
• Color contrast ratio should meet WCAG AA (4.5:1 for normal text).
• Line height should be 1.4-1.7 for comfortable reading.
• Test with Chrome Lighthouse accessibility audit.

If you use Oversearch, open AI Page Optimizer → Benchmark Breakdown to check typography signals.

What’s an accessible font size for body text?

16px minimum for body text, with 18-20px being ideal for long-form content on screens.

Smaller text causes eye strain, increases bounce rate, and fails mobile usability checks. For an aging population with varying vision abilities, larger text is more inclusive.

• Body text: 16-20px.
• Headings: proportionally larger (H1: 2-2.5x body, H2: 1.5x body).
• Line height: 1.5-1.7 of font size.
• Never set font-size below 14px for any readable text.

If you use Oversearch, open AI Page Optimizer → Benchmark Breakdown to verify.

How do I improve readability without changing the brand?

Adjust spacing, contrast, and sizes within your existing brand guidelines. Most readability improvements do not require changing fonts or colors.

Readability is often about whitespace and sizing, not about the specific font family or brand colors. Small adjustments to line height, paragraph spacing, and contrast can make a big difference.

• Increase line height to 1.5-1.7 (often the single biggest improvement).
• Add more whitespace between paragraphs and sections.
• Increase body font size to at least 16px.
• Improve color contrast to meet WCAG AA (4.5:1).
• Use your brand font at a larger, more readable size.

If you use Oversearch, open AI Page Optimizer → Benchmark Breakdown to check.

How can I verify the fix after I change the page?

Run a Lighthouse accessibility audit and check that text size, contrast, and spacing meet standards.

• Lighthouse: run with the Accessibility category enabled.
• Check color contrast with Chrome DevTools (Elements → Computed → contrast ratio).
• Verify font sizes with DevTools on the body and heading elements.

If you use Oversearch, open AI Page Optimizer → Benchmark Breakdown to confirm.

Common root causes

• Slow load times / Core Web Vitals issues.
• No mobile responsiveness or incorrect viewport settings.
• Aggressive popups/interstitials blocking content access.
• Mixed content or HTTPS misconfiguration.

How to detect

• In Oversearch AI Page Optimizer, open the scan for this URL and review the Benchmark Breakdown evidence.
• Verify the signal outside Oversearch with at least one method: fetch the HTML with curl -L, check response headers, or use a crawler/URL inspection.
• Confirm you’re testing the exact canonical URL (final URL after redirects), not a variant.

How to fix

Check your typography (see: What’s an accessible font size for body text?) and improve readability within your brand (see: How do I improve readability without changing the brand?). Then follow the steps below.

1. Improve load speed and address Core Web Vitals issues (LCP/CLS/TBT).
2. Ensure mobile responsiveness and correct viewport settings.
3. Remove or delay aggressive popups that block main content.
4. Ensure HTTPS is enabled and fix mixed content warnings.
5. Run an Oversearch AI Page Optimizer scan to confirm technical quality improvements.

Implementation notes

• If you use a third-party script for popups/ads, test without it to confirm it’s the blocker.
• Mixed content often comes from legacy image/script URLs; fix at the source or via rewrite rules.
• Mobile issues commonly come from missing viewport meta or rigid layouts.

Verify the fix

• Run an Oversearch AI Page Optimizer scan for the same URL and confirm the benchmark is now passing.
• Confirm the page is 200 OK and the primary content is present in initial HTML.
• Validate with an external tool (crawler, URL inspection, Lighthouse) to avoid false positives.

Prevention

• Track Core Web Vitals and regression test after UI changes.
• Avoid interstitials that block content on load.
• Enforce HTTPS and monitor mixed content in CI or monitoring.

FAQ

What is a good color contrast ratio?

WCAG AA requires 4.5:1 for normal text and 3:1 for large text (18px+ bold or 24px+ regular). Check with Chrome DevTools or a contrast checker tool. When in doubt, use dark text on a light background — the safest combination.

Does line height affect SEO?

Not directly, but poor line height increases bounce rate. Line height of 1.5-1.7 times the font size is ideal for readability. When in doubt, set line-height: 1.6 for body text.

Should I use system fonts for better performance?

System fonts eliminate font loading time, which improves LCP. If brand fonts are required, use font-display: swap and preload the critical font file. When in doubt, system fonts are the fastest option.

Can web fonts cause layout shift (CLS)?

Yes. When a web font loads and replaces the fallback font, it can shift text and surrounding elements. Use font-display: swap and set size-adjust on the fallback to minimize the shift. When in doubt, preload your primary font and use a size-matched fallback.

How do I check contrast ratios quickly?

In Chrome DevTools, click on any text element, and the Styles panel shows the contrast ratio with a pass/fail indicator. You can also use browser extensions like axe or WAVE. When in doubt, run Lighthouse accessibility audit.

How can I verify the typography fix?

Run Lighthouse accessibility audit, check body font size is at least 16px, and verify contrast ratios meet WCAG AA. When in doubt, run an Oversearch AI Page Optimizer scan.