Sites using SmtpJS
Client-side JavaScript library for sending email via SMTP from the browser.
Get told when a new site ships with SmtpJS.
Stackdar watches every launch we detect and sends you the ones using SmtpJS, by email, Slack or webhook. On every plan, from £15 a month.
See how alerts work38 sites
33 found by StackScope, 5 via launch platforms
- StackScope Wider Web 32
- StackScope Discovery (Indie) 1
- Product Hunt 5
SmtpJS has been detected on 38 launches we've crawled. The 7-day rolling share is 0.0%, roughly steady week on week. Most recent detection: ONBO, yesterday.
It's most commonly paired with Font Awesome, Cloudflare, and HTTP/3. By product type, the launches using it are most often Developer Tools (18%), Education (18%), and AI (9%).
What kind of products ship with SmtpJS
11 launches
Domain endings using SmtpJS
38 sites
- .com 23.68%
- .in 18.42%
- .site 18.42%
- .ai 13.16%
- .dev 5.26%
- .tech 5.26%
- .me 2.63%
- .online 2.63%
- .org 2.63%
Share of new sites using SmtpJS
Each dot is one launch day. Line is the 7-day rolling average; weekly averages before June 2026.
The shaded part of the chart is measured against a different set of sites. Until 8 July 2026 we only tracked launches from launch platforms; from that date we crawl the wider web as well. The share is a proportion of whatever we were tracking at the time, so it can step at that line without the technology itself changing. For a single continuous measure, switch to launch platforms.
How StackScope detects technologies
⋮ Jul 1, 2026: Adoption figures now count launches from launch platforms. Use the source view to include StackScope Discovery.
⋮ Jul 3, 2026: Email provider detection improved: providers identified from mail configuration are now caught on a site's first crawl. Earlier data may slightly undercount.
Transactional Email leaders
| Tool | % of launches | % of category | ||
|---|---|---|---|---|
| #1 | – |
Resend
|
5.36% | 62.86% |
| #2 | ▲1 |
SendGrid
|
0.66% | 7.79% |
| #3 | ▼2 |
Amazon SES
|
0.64% | 7.45% |
| #4 | ▲1 |
MailChannels
|
0.52% | 6.10% |
| #5 | – |
Mail.Baby
|
0.45% | 5.24% |
| … | ||||
| #35 | ▼6 | SmtpJS Current page | <0.01% | 0.02% |
Percentages show adoption among indie launches: the share of all analysed launches, and of launches using any Transactional Email tool.Among August launches it ranked #37 in Transactional Email, down from #31 in July. All 150 in Transactional Email →
Often used with
| Tool | Sites |
|---|---|
Font Awesome
|
23 |
Cloudflare
|
21 |
| HTTP/3 | 21 |
jsDelivr
|
18 |
cdnjs
|
17 |
Tools most often detected on the same sites as SmtpJS.
Recent launches we can show
6 of the 38 sites using SmtpJS are product launches we list individually. The other 32 are sites we found crawling the wider web: they count towards the figures above, but we do not publish them one by one. How StackScope Discovery works
ONBO
EduTree | Unified Educational Management Software & LMS
Education
Sunlit Urbana Panchkula
Main Street PT
Health
CORA
TATVA
Hiring & HR
The StackScope API serves all 38 sites using SmtpJS, filterable and exportable, from £15 a month.