The complete font inspector.
Kern matches the effortless hover-to-identify flow you know — then goes far deeper than any other font tool on the store.
Hover any text, click to pin. Family, size (px/rem/pt), weight, style, line-height, letter-spacing and color.
Kern highlights the winning font in the full stack — so you finally know why your font isn't showing.
Every family in use, usage counts, total font payload in KB, and flags like missing font-display: swap.
Swap any element — or the whole page — from Google Fonts or your own font file. Fully reversible.
Drag weight, width, slant and optical-size axes and watch the live page re-render as you move.
Every inspected color pair is graded AA / AAA on the spot, with large-text rules applied correctly.
Vetted heading/body pairings for 60+ popular fonts — previewable on the live page in one click.
Copy as CSS, Tailwind, or design-token JSON. Export full page audits as shareable JSON.
HEX, RGB, HSL and OKLCH. Plus fluid-type detection, OpenType feature toggles, and a glyph coverage map.
Built like an instrument.
See the whole type system.
One click scans everything a page loads: every family, its weights and usage, the total font payload in kilobytes — with problem flags for unused fonts, FOIT risk and family bloat. It's a performance review for typography.
Try any font, live.
Swap fonts on the real page — no mockups, no guessing. Pull from the Google Fonts library or upload your own file; uploads stay in the tab and vanish on reload. Drag variable axes and watch the page follow.
Export clean, real code.
Anything you inspect or collect exports as tidy CSS, Tailwind utilities and config, or design-token JSON — copy to clipboard or download. Built for handing straight to a codebase.
Perfect pairings, ready.
A curated pairing library covers 60+ popular families with vetted heading-and-body combinations — each previewable on the page you're looking at, loaded on demand from Google Fonts.
Private by architecture, not by promise.
Kern has no server. Everything runs locally in your browser: it collects nothing, transmits nothing, and needs no account. Uploaded try-on fonts never leave your machine. The only network request Kern ever makes is fetching a Google Font — and only when you ask it to. Read the full privacy policy →
Free forever. Powered by goodwill.
Kern is free with no paywall, no pro tier and no ads. If it saves you time and you'd like to keep independent tools like this alive, a coffee goes a long way.
☕ Support Kern on Ko-fi