1
At a glance the headline numbers for Image CDNs impact
Performance impact by image_cdn provider.
9
Providers ranked
After min-sites filter
30,346
Sites in sample
Combined across all items
0.02
Best CLS (p75)
Fastly Image Optimizer
The State of Web Vitals · October 2026 · 210,902 crawled sites · all devices field datacorewebvitals.io/state-of-cwv
2
The ranking sorted by CLS at p75, fastest first
| # | Provider | CLS p75 | Passing | Sites | |
|---|---|---|---|---|---|
| 1 | Fastly Image Optimizer | 0.02 | 87.9% | 1,282 | |
| 2 | Sirv | 0.05 | 82.5% | 65 | |
| 3 | Imgix | 0.05 | 85.8% | 866 | |
| 4 | Akamai Image Manager | 0.05 | 85.1% | 8,026 | |
| 5 | Bunny Image Optimizer | 0.05 | 86.1% | 19,121 | |
| 6 | ImageKit | 0.06 | 79.8% | 88 | |
| 7 | Uploadcare | 0.06 | 86.6% | 102 | |
| 8 | Cloudinary | 0.13 | 71.7% | 577 | |
| 9 | Thumbor | 0.20 | 61.1% | 219 |
The State of Web Vitals · October 2026 · 210,902 crawled sites · all devices field datacorewebvitals.io/state-of-cwv
3
Passing CLS per provider which group passes the CLS most often
ProviderSitesPassing CLSp75
Fastly Image Optimizer 0.6% 1,282 0.02
Uploadcare 0% 102 0.06
Bunny Image Optimizer 9.1% 19,121 0.05
imgix 0.4% 866 0.05
Akamai Image Manager 3.8% 8,026 0.05
Sirv 0% 65 0.05
ImageKit 0% 88 0.06
Cloudinary 0.3% 577 0.13
Thumbor 0.1% 219 0.20
Good Needs Improvement Poor Sorted best-passing first · median colored by its own rating · pass = good CLS (0.1 at p75) · one value per site
88% of Fastly Image Optimizer sites pass CLS. Thumbor trails 27 points behind, leaving 39% of its sites failing. computed
The State of Web Vitals · October 2026 · 210,902 crawled sites · all devices field datacorewebvitals.io/state-of-cwv
4
All five vitals at once the whole category without toggling - cell is the pass rate, small number the p75
LCP
INP
CLS
FCP
TTFB
Bunny Image Optimizer 9.1%
822.2s
96113ms
860.05
771.7s
591.2s
Akamai Image Manager 3.8%
812.2s
95117ms
850.05
771.7s
561.2s
Fastly Image Optimizer 0.6%
881.7s
93117ms
880.02
901.2s
80727ms
imgix 0.4%
862.1s
91137ms
860.05
851.5s
74848ms
Cloudinary 0.3%
802.3s
77180ms
720.13
771.7s
591.1s
Thumbor 0.1%
842.2s
94137ms
610.20
821.6s
68934ms
Uploadcare 0%
902.0s
90160ms
870.06
881.4s
84668ms
ImageKit 0%
672.8s
85146ms
800.06
662.0s
521.2s
Sirv 0%
772.5s
96111ms
830.05
672.2s
471.5s
60%95%+ passing Cell: pass rate, small number = p75 · faded rows: under 100 sites
One row per provider, one column per vital - the cell is the share of sites passing, the small number the p75. No toggling needed to see where the category actually differs.
Fastly Image Optimizer leads on CLS: 88% of its sites pass. Thumbor trails at 61%. computed
The State of Web Vitals · October 2026 · 210,902 crawled sites · all devices field datacorewebvitals.io/state-of-cwv
Related signals Search (6) → Font services (4) → Personalization (6) → CDN (16) → 210,902 crawled sites with Chrome field data, representing millions of real page loads · How we measured
210,902 crawled sites with Chrome field data, representing millions of real page loads. How we measured.