Rack CORS on new websites

1. Rack CORS appeared on about 720 new sites in the last 30 days.^[1]
2. Almost all new Rack CORS sites also use Google Tag Manager.
3. It is unusually common on .store domains: 37% of the domains running it, against 2.1% of domains across new sites.

The line is the 7-day average share of new sites that use Rack CORS, since 10 September.

#	Movement	Tool	Share of all sites	Share of category	Bar
1	–	Vite	23.7%	98.3%
2	–	pywb (Wayback Machine toolkit)	0.1%	0.3%
3	▲1	Instant.page	0.1%	0.2%
4	▼1	Weglot	<0.1%	0.2%
5	▲2	Rack CORS	<0.1%	0.1%

All-time shares across the new sites we track: of all of them, and of the sites using any Developer Tools tool. Among September launches it ranked #5 in Developer Tools, up from #7 in August. All 506 in Developer Tools

Tool	Sites with both	vs all new sites	Bar
Fourthwall	2,102	2600x
Google Cloud Storage	2,009	475x
Stripe	2,136	99x
Microsoft Clarity	2,129	89x
Facebook Pixel	2,134	29x

Tools that turn up far more often on Rack CORS sites than on new sites in general, and how many times as common each one is there.

51 of the 2,153 sites using Rack CORS are product launches we list individually. The other 2,102 are new business and personal sites: they count towards the figures above but are not listed here. A watch sends them to you.

Site	Found	Also detected
Synthetic Muse syntheticmuse.ai	Oct 5
BirdBinge getbirdbinge.com	Oct 4
Letters from the West lettersfromthewest.com	Oct 4
Pimpen — Tire Paint Markers for Tire Lettering pimpen.store	Oct 3
ClipSnipers | Performance-Based Clipping Campaigns clipsnipers.com · Marketing	Oct 2
GlassGrid glass-grid.store · Productivity	Oct 1
Social By Valkence - Interest-Based social.valkence.com	Sep 28
Family Court Survival System familycourtsurvivalguide.com	Sep 25
Sunday By Valkence - Global Activities sunday.valkence.com	Sep 25
Log To Print Universe logtoprint.com · Design	Sep 13
permanent underclass underclass.store	Sep 10
Trench: Decay | studiorook. trenchdecay.com	Sep 10

Showing the most recent 12 of 51.

Watches, exports and the API give you all 2,153 sites using Rack CORS, from £15 a month.

1. These figures cover websites that went live since April 2026, not the web as a whole.
2. Country comes from what each site says about itself, such as a company registration, legal terms or a phone number, not just its domain ending. Too few sites state their country plainly for the usual count, so this one also counts single signals: a country domain ending, a phone number (for North America, its area code), a location the site declares in its own page metadata, or a country-specific vendor stack and the page language where they agree and nothing contradicts them. Read these as likely rather than certain.