The State of Web Vitals

Font format mix

Font formats in use: woff2, woff, ttf and friends.

Field data PhoneDesktopAll Scope All sites Q1 2026 edition · Phone field outcomes
Metric LCP INP CLS
1

At a glance the headline numbers for Font format mix

Font formats in use: woff2, woff, ttf and friends.

6
Categories
In the distribution
82.2%
Fleet share
Top: woff2
84.6%
Sites with any
Of woff2

82.2% of font files are WOFF2.

The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
2

The font format mix mix who uses what, and how stable each group is

Median CLS (sites using feature)
0
0.10
0.20
0.30
0.40
0.50
Woff20.0082% of sites
Woff0.0010% of sites
Ttf0.007% of sites
Otf0.001% of sites
Other0.001% of sites
Eot0.000% of sites
VariantShare of requestsMedian
Woff2
82%
0.00
Woff
10%
0.00
Ttf
7%
0.00
Otf
1%
0.00
Other
1%
0.00
Eot
0%
0.00

Font format mix. On the fleet: 82.2% woff2, 9.7% woff, 6.9% ttf. 84.6% of sites use at least one woff2.

Woff2 leads by count (82.2%) and by bytes (73.8%). computed

The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
3

Passing CLS per bucket every category and count level at once - color is the pass rate

1
2
3
4
5
6
7
8
9
10
Woff2 82.2%
89
90
89
89
89
88
87
86
86
88
Woff 9.7%
89
88
86
87
85
88
85
Ttf 6.9%
87
88
87
82
84
88
83
80
Otf 0.8%
83
84
84
92
90
76
92
Other 0.5%
87
80
78
85
70
90
82
← few of this category on the pagemany →
60%95%+ of sites passing CLS Faded cells: under 100 sites

Each row is a category, each column its own count bucket (few on the left, many on the right); the cell is the share of those sites passing CLS.

Otf swings the hardest: 83% of sites pass CLS with few, 92% with many. computed

The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
4

Few vs many - does quantity cost CLS? the pass rate with few vs many of each category

60%70%80%90%100% few → many
Ttf 6.9% 87% → 80%
Other 0.5% 87% → 80%
Woff 9.7% 89% → 85%
Woff2 82.2% 89% → 88%
Otf 0.8% 83% → 92%
% of sites passing CLS · hollow ring = pages with few, solid dot = pages with many

Per category: the pass rate among pages with FEW of it (hollow ring) against pages with MANY (solid dot), worst trend first. Thin buckets are excluded from the endpoints.

More Ttf costs the most: the CLS pass rate falls from 87% with few to 80% with many. computed

The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
5

Why this matters for the Core Web Vitals, and where to start fixing it

woff2 is the only font format a modern site needs. It compresses tighter than woff and far tighter than ttf or otf, and every current browser supports it. Anything else in the mix is either a legacy fallback nobody downloads or bytes wasted on the wire.

Font bytes sit on the render path. Text either waits for them or reflows when they arrive, so smaller font files shorten that window whatever your font-display strategy is.

How does this affect the Core Web Vitals?

The choice barely moves the LCP: 81% pass at best, 78% at worst. This signal does not separate passing sites from failing ones.

Go fix it Self-host Google Fonts → Responsive font loading strategy →
Related signals Uses @import → font-display strategy → Images per page → Cookies per site → Chrome field data from 94,910 sites, representing millions of real page loads · How we measured