Accessible Font Size Checker
Enter a font size and its role to check it against readability best practices, with instant px, rem, and pt conversions and a live preview.
Is your text big enough to read?
Font size is one of the most common accessibility misses. Body copy set too small forces users to zoom, and fine print below about 12px is genuinely hard to read for many people. This checker takes a size and the role it plays — body, caption, or heading — and tells you whether it clears the practical readability thresholds, with a live sample rendered at that exact size.
It also converts between the units you'll actually use: px, rem, pt, and em, calculated against your chosen root size. For final CSS, prefer rem so text honors each visitor's browser font settings rather than locking a fixed pixel value. Aim for roughly 16px body text as a floor, and reserve small sizes for genuinely secondary content.
Guidance, not gatekeeping
These are best-practice thresholds; always test with real content and real users where you can.
Frequently Asked Questions
What font size is considered accessible for body text?
Around 16px (1rem) is the widely recommended minimum for body copy. Smaller than about 12px becomes hard to read for many users and should be avoided for anything but incidental text.
Why prefer rem over px for font size?
rem scales with the user’s browser font-size setting, so text respects their accessibility preferences. Fixing sizes in px can override those settings and harm readability.
Does font weight affect readability?
Yes. Very light weights at small sizes reduce legibility, especially at low contrast. Keep small text at a normal or medium weight rather than thin.
Is this tool free and private?
Yes. The checks run in your browser — no sign-up and nothing uploaded.
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