What are kerning pairs?

Kerning pairs are combinations of two glyphs whose default spacing needs manual adjustment in a font — classics like AV, To, or Ya. Type designers work through a list of such pairs in their font editor and assign each one a kerning value. This tool generates those lists automatically from any character set.

What do the ABA, AB, and BA patterns mean?

AB produces straight two-glyph pairs (AV). BA reverses them (VA). ABA wraps the pair in its first glyph (AVA), which makes spacing easier to judge because the eye compares the gap on both sides of the middle glyph.

How do I use the proof strings in a font editor?

Use Glyphs Sample Strings or RoboFont Space Center for one-pair-per-line Unicode proof text. For FontLab and other editors, use one of the portable newline, spaced, or continuous text presets and paste it into the editor’s text or metrics view.

Can I preview the pairs in my own font?

Yes. Click “Load font…” or drag an OTF, TTF, WOFF, or WOFF2 file onto the preview. The font is loaded locally with the browser’s FontFace API and never uploaded anywhere.

Which languages and scripts are supported?

There are 44 presets covering Armenian, English, French, German, Spanish, Portuguese, Greek, Hebrew, Arabic, Persian, Russian, Ukrainian, Polish, Czech, Georgian, Hindi, Bengali, Tamil, Thai, Korean, Japanese, Chinese, Vietnamese, Turkish, and more — and you can paste any custom glyph set.

What are context control strings like HH and OO?

A standard spacing-proof technique: each pair is set between control glyphs with known sidebearings (straight controls like HH or nn, round controls like OO or oo), so you judge the pair against a stable reference instead of in isolation.

Yes — completely free, no account, no upload. Everything runs in your browser, and your session (characters, settings, flagged pairs) is saved locally between visits.

Kerning workbench

Font QA Studio

Compare two versions

Drop an earlier build and a later one to see exactly what changed: glyphs added or dropped, feature and kerning changes, and vertical-metric, OpenType-table, and variable-axis edits. (Per-glyph outline shapes are not compared.)

Base (older)

Drop the base (older)

TTF, OTF, WOFF, WOFF2 — parsed locally.

Candidate (newer)

Drop the candidate (newer)

TTF, OTF, WOFF, WOFF2 — parsed locally.