Customer.io on new websites
Customer.io marketing automation and transactional email.
471 sites
364 found by StackScope, 107 via launch platforms
- StackScope Wider Web 337
- StackScope Discovery (Indie) 27
- Product Hunt 89
- Hacker News 11
- PeerPush 6
- Other 1
Customer.io appeared on about 130 new sites in the last 30 days.
These figures cover websites that went live since April 2026, not the web as a whole.
Get told when a new site ships with Customer.io.
133 new sites with Customer.io first seen in the last 30 days.
Stackdar watches every launch we detect and sends you the ones using Customer.io, by email, Slack or webhook. On every plan, from £15 a month.
See how alerts workShare of new sites using Customer.io
Each dot is one launch day. Line is the 7-day rolling average; weekly averages before July 2026.
The shaded areas were measured against a different set of sites, so the line can step there without Customer.io itself changing.
Coverage details
Before the dashed line where the dots begin, the line is a weekly average. After it, the last 90 days are shown one day at a time.
Grey: before 8 July 2026, we only tracked launches from launch platforms. From that date we crawl the wider web as well.
Amber: 8 July to 10 September 2026, before we improved our infrastructure to index new sites much sooner, often on the day they go live. Sites found that early often haven't finished setting up, so anything usually added after launch reads lower from 10 September. We record each site as it was when we found it.
The share is a proportion of whatever we were tracking at the time. For a single continuous measure, switch to launch platforms.
What kind of sites use Customer.io
189 sites with a known type, all time
Domain endings using Customer.io
470 sites, all time
- .site 38.7%
- .com 34.0%
- .ai 3.8%
- .io 3.6%
- .co 3.2%
- .online 2.1%
- .so 1.9%
- .xyz 1.7%
- .app 1.5%
- .org 1.5%
- .space 1.3%
- .dev 0.9%
- .new 0.9%
- .me 0.6%
Country
Country known for 50 of 471 sites (10.6%), all time.
How we know
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. We count a country only where it is stated plainly enough to be sure: a governing-law clause or company registration number on a legal page, a phone country code, or a country domain ending. Sites that publish none are not counted at all.
-
United States
80.0%
-
India
6.0%
-
Spain
4.0%
-
Australia
2.0%
-
Canada
2.0%
-
United Kingdom
2.0%
-
Sweden
2.0%
-
Slovakia
2.0%
Green hosting
107 checked sites since Apr 2026.
What this means
The share whose web host The Green Web Foundation lists as running on green energy, against the average for every new site we checked.
- Customer.io 30%
- Average 47%
Email Marketing leaders
| Tool | % of sitesall time | % of categoryall time | ||
|---|---|---|---|---|
| #1 | ▼1 |
Brevo
|
0.8% | 32.5% |
| #2 | ▲8 |
Hostinger Reach
|
0.7% | 28.5% |
| #3 | ▼1 |
Klaviyo
|
0.3% | 11.4% |
| #4 | – |
HubSpot
|
0.2% | 6.4% |
| #5 | – |
Mailchimp
|
0.1% | 5.0% |
| … | ||||
| #17 | ▲1 |
Customer.io
Current page
|
<0.1% | 0.3% |
Percentages show all-time adoption across the new sites we track: the share of all of them, and of the sites using any Email Marketing tool.The most common alternatives to Customer.io on new websites are Brevo and Mailchimp. All 279 in Email Marketing →
Often used with
| Tool | Sites | vs all new sites |
|---|---|---|
X (Twitter) Ads
|
285 | 505x |
Amplitude
|
264 | 366x |
Stripe
|
277 | 58x |
Google Sign-In
|
264 | 33x |
Google Ads
|
341 | 27x |
Tools that turn up far more often on Customer.io sites than on new sites in general, and how many times as common each one is there.
Recent launches using Customer.io
134 of the 471 sites using Customer.io are product launches we list individually. The other 337 are sites we found crawling the wider web: they count towards the figures above, but we do not publish them one by one. They are included in the StackScope API and in Stackdar alerts. How StackScope Discovery works
Kanbanchi
Oct 10, 2026 · score 6.1 · Productivity
Also detected
Say what you need. We turn it into a course — COPYMIND
Also detected
Say what you need. We turn it into a course — COPYMIND
Also detected
Decisão de crédito até 30 segundos | Robbin
Also detected
Maltexi | Traceability, EDI & File Exchange Software
Also detected
Griffin by Tavus
Oct 8, 2026 · score 6.7 · AI
Also detected
Say what you need. We turn it into a course — COPYMIND
Also detected
dinerr
Also detected
Recruit My Game
Sep 30, 2026 · score 10.0 · Education
Also detected
GitHub 全球加速站 · 开发者专属的 GitHub 加速网关
Also detected
ShiftFence — Geofenced Time Clock for Parking, Valet, Security & Staffing
Also detected
Showing the most recent 12 of 134.
The StackScope API serves all 471 sites using Customer.io, filterable and exportable, from £15 a month.