Font Size and Legibility Checker
Checks rendered text is not too small to read comfortably on mobile.
Runs a real Chromium page load — usually takes 5–15 seconds.
What this tool checks
Legible font sizes on mobile
On the mobile render, checks what share of text uses a computed font size below 12px.
Why it matters: Text under about 12px forces mobile users to pinch-zoom to read, which is a poor experience.
If it fails: Use a base font size of at least 16px for body text on mobile.
Source: web.dev/articles/font-size
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