Which OpenType features the files declare
Kerning is declared in 78% of Google Fonts families, fractions in 50%, tabular figures in 18% and true small capitals in only 9%. The median family declares 11 OpenType feature tags.
Reading feature tags
OpenType features are switches inside the font file: kern adjusts spacing between pairs, liga joins letters such as f and i, tnum gives figures of equal width for tables. Each family’s regular file declares its features in two tables, and we read the list of tags. A declared tag shows that the feature exists; it does not show how complete it is. Families without a kern tag may still carry older kerning data, so the kerning count is a lower bound.
| Feature | Tag | Families | Share | Sans serifs | Serifs |
|---|---|---|---|---|---|
| kerning | kern | 1,477 | 78% | 85% | 81% |
| ordinals | ordn | 1,126 | 59% | 72% | 55% |
| standard ligatures | liga | 959 | 51% | 51% | 57% |
| fractions | frac | 947 | 50% | 52% | 52% |
| superscripts | sups | 929 | 49% | 52% | 49% |
| case-sensitive forms | case | 684 | 36% | 39% | 36% |
| discretionary ligatures | dlig | 419 | 22% | 24% | 29% |
| tabular figures | tnum | 347 | 18% | 26% | 20% |
| stylistic alternates | salt | 288 | 15% | 15% | 13% |
| slashed zero | zero | 266 | 14% | 17% | 14% |
| old-style figures | onum | 234 | 12% | 13% | 20% |
| small capitals | smcp | 179 | 9% | 10% | 18% |
| swashes | swsh | 24 | 1% | 0% | 2% |
Typographic figures and small capitals
Features that matter for careful text setting are the exception. Old-style figures appear in 234 families and small capitals in 179. Serifs carry small capitals more often than the library as a whole (18% against 9%), which fits their use in books. Tabular figures, needed to line up numbers in columns, are in 347 families, most of them sans serifs.
Changes over time
The share of families with each feature depends on when they were added. The table groups families by year of addition.
| Added | Families | Kerning | Tabular figures | Old-style figures | Small capitals |
|---|---|---|---|---|---|
| 2010 to 2012 | 639 | 69% | 6% | 7% | 7% |
| 2013 to 2017 | 220 | 70% | 26% | 20% | 16% |
| 2018 to 2021 | 521 | 86% | 16% | 12% | 7% |
| 2022 to 2026 | 519 | 83% | 32% | 15% | 13% |
Kerning rose from the first years to the latest; tabular figures are far more common among recent additions than among the earliest ones.
Ligatures and alternates by class
Contextual alternates, which swap a letter for a variant depending on its neighbours, are declared by 29% of handwriting families against 16% of sans serifs: connected scripts use them to join letters naturally. Of the substitution features in the table above, only ordinals are declared more often than standard ligatures, and discretionary ligatures, the decorative kind that is off by default, appear in 22% of families.
Four kinds of figures
A complete figure set offers lining and old-style figures, each in a proportional and a tabular version. In all, 129 families declare all four features; 47 of them are serifs and 62 sans serifs. Far more common is a single alternative: 195 families declare tabular figures without old-style ones. Of the 179 families with small capitals, 163 can also turn capitals into small capitals (c2sc), which is what setting acronyms in small capitals needs.
Kerning by class
Kerning adjusts the space between particular pairs such as AV or To. It is declared by 85% of sans serifs and 81% of serifs but by only 9% of monospaced families, whose fixed cells are meant to stay fixed. Handwriting families declare it in 77% of cases.
Swashes
Swash letters, alternates with extended flourishes, are the rarest feature in the table: 24 families declare them, including Allura, Arsenal, Arsenal SC and Bellota.
Fractions, superscripts and ordinals
The small conveniences are common. Ordinals, which raise the letters in 1st or 2º, are declared by 59% of families, fractions by 50% and superscripts by 49%. Subscripts, needed for chemical formulas, are rarer at 24%. Case-sensitive forms, which raise hyphens and brackets to sit well with capitals, appear in 36%.
The slashed zero
The zero feature swaps the plain 0 for a slashed or dotted one so it cannot be mistaken for the letter O. It is declared by 266 families, 14% of the library, but 32% of monospaced families, where telling the two apart matters most in code and data.
Scripts and feature counts
Families listing five or more subsets declare a median of 19 feature tags; families with one or two subsets declare 3.0. Marks, contextual forms and language-specific variants for each script all count, so a long feature list often says more about script coverage than about typographic extras.
Stylistic sets
A stylistic set is a named group of alternate letters; 596 families (31%) include at least one. Moderustic has 20, the most in the library, followed by Akatab, MonteCarlo and Spline Sans Mono. By class, stylistic sets are most frequent among monospaced families and least frequent among display faces.
The longest feature lists
Chiron Hei HK declares 74 feature tags, the longest list in the library; Chocolate Classical Sans, Akatab, Google Sans and Andika complete the top five. Scripts beyond Latin bring their own positioning and substitution features, so families with many subsets tend to declare more tags.
Where to see them
Each family page lists the common features its file declares. To see how often a family’s features occur elsewhere, compare it with its measured neighbours or filter the type finder by class.
Sources
Family metadata (METADATA.pb) and font files from the google/fonts repository as of 28 October 2026; all measurements computed by this site as described in How we measure.