The State of Web Vitals

Image format mix

The image mix by format (JPEG, PNG, WebP, AVIF, SVG, GIF) - counts and bytes per format.

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

At a glance the headline numbers for Image format mix

The image mix by format (JPEG, PNG, WebP, AVIF, SVG, GIF) - counts and bytes per format.

12
Categories
In the distribution
29.1%
Fleet share
Top: jpg
72.4%
Sites with any
Of jpg

5.5% of images are AVIF. 29.1% are still JPEG.

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

The image 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
Jpg0.0329% of sites
Png0.0322% of sites
Webp0.0319% of sites
Svg0.0318% of sites
Avif0.026% of sites
Gif0.034% of sites
Other0.032% of sites
Ico0.030% of sites
VariantShare of requestsMedian
Jpg
29%
0.03
Png
22%
0.03
Webp
19%
0.03
Svg
18%
0.03
Avif
6%
0.02
Gif
4%
0.03
Other
2%
0.03
Ico
0%
0.03
Png+xml
0%
Webp+xml
0%
Jpg+xml
0%
67mqhd9k
0%

Image format mix. On the fleet: 29.1% jpg, 22.1% png, 19.1% webp. 72.4% of sites use at least one jpg.

Jpg leads by count (29.1%) and by bytes (53.8%). computed

The State of Web Vitals · Q1 2026 · 94,910 sites · desktop 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
11
Jpg 29.1%
80
78
79
77
77
76
75
76
74
76
Png 22.1%
80
79
77
77
78
77
76
77
73
72
74
Webp 19.1%
77
78
81
79
78
78
77
75
76
75
Svg 18.3%
77
78
78
78
76
77
79
78
76
75
Avif 5.5%
82
86
83
82
83
80
77
80
83
80
Gif 4.1%
78
77
75
77
74
75
74
79
73
72
Other 1.8%
78
75
76
74
75
71
75
73
75
77
← 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.

Png swings the hardest: 80% of sites pass CLS with few, 74% with many. computed

The State of Web Vitals · Q1 2026 · 94,910 sites · desktop 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
Png 22.1% 80% → 74%
Gif 4.1% 78% → 72%
Jpg 29.1% 80% → 76%
Webp 19.1% 77% → 75%
Svg 18.3% 77% → 75%
Avif 5.5% 82% → 80%
Other 1.8% 78% → 77%
% 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 Png costs the most: the CLS pass rate falls from 80% with few to 74% with many. computed

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

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

Image bytes are usually the biggest slice of page weight, and the format multiplies all of them. AVIF and WebP deliver the same picture in far fewer bytes than JPEG. PNG belongs to screenshots and graphics, not photos. GIF is the most expensive way ever invented to ship a short video.

Nobody converts by hand at scale. An image CDN or build step negotiates the best format per browser from one source file. This mix mostly measures how many sites have that step in place.

How does this affect the Core Web Vitals?

Image format mix correlates with the LCP. With AVIF, 90% of sites pass the LCP. With Other, 84% do.

Go fix it Optimize images for Core Web Vitals → JPEG XL and Core Web Vitals →
Related signals Stylesheet origin (1P/3P) → Preloaded fonts → Stylesheet loading mix → Third-party share → Chrome field data from 94,910 sites, representing millions of real page loads · How we measured