Crux
Crux lets your team iterate, comment and approve right on the running prototype, with your research and evidence linked to every design. Built for designers, UX researchers and product teams. Free plan available.
Added 8 Nov 2026
Analysed 8 Nov 2026
via 
What we found
- It sends one of the six security headers we check; Content-Security-Policy is among those missing.
- It publishes SPF but no DMARC record, so receivers decide for themselves what to do with email that fails.
- It has no robots.txt or sitemap, the two files that help search engines find its pages.
- Built with Next.js and React, the site is hosted on Vercel, with a domain registered in 2025.
- One more gap is listed further down the page.
Built with: 20 technologies · Indie stack
Embed this on your site
For light pages
<a href="https://firstsited.com/launch/33lbz7pj/crux"><img src="https://firstsited.com/badge/33lbz7pj/stack.svg" alt="Crux tech stack on FirstSited" height="28"></a>
For dark pages
<a href="https://firstsited.com/launch/33lbz7pj/crux"><img src="https://firstsited.com/badge/33lbz7pj/stack.svg?theme=dark" alt="Crux tech stack on FirstSited" height="28"></a>
How it fits together
Each technology runs on, or extends, the one it sits under.
| Technology | Type |
|---|---|
| Infrastructure | |
Google Domains DNS
|
DNS |
Vercel
|
Hosting |
| HSTS | Security |
Google Workspace
(3)
|
Business email |
Resend
|
Transactional email |
| Build & Framework | |
Clerk
(6)
|
Auth |
Cloudflare Turnstile
|
Captcha |
Tailwind CSS
|
CSS framework |
React
(2)
|
Framework |
Motion
|
JavaScript library |
Three.js
|
JavaScript library |
Next.js
(6)
|
Meta-framework |
Base UI
|
UI library |
Lucide Icons
|
UI library |
| Analytics & Marketing | |
Google Analytics
(4)
|
Analytics |
Vercel Analytics
(2)
|
Analytics |
Google
|
Consent |
Google Search Console
|
SEO |
Google Tag Manager
(4)
|
Tag management |
| Business Tools | |
Crisp
|
Chat |
Each technology links to its own page: which other new sites launched with it.
Site checks
| Custom title and meta description | |
| Open Graph tags (title, image, description) | |
| Twitter card meta tags | |
| Responsive viewport meta tag | |
| Favicon present | |
| Semantic HTML (nav, main, article) | |
| Page title is 65 characters Google only shows about 60 characters of the title in search results; aim for 50–60 to keep the whole thing visible. | |
| Meta description is 212 characters Google only shows about 155–160 characters of the description in desktop search results (less on mobile); anything past that won't appear. | |
| Canonical URL declared |
| Referrer-Policy | |
| X-Frame-Options | |
| Permissions-Policy experimental | |
| X-Content-Type-Options | |
| Content-Security-Policy | |
| Strict-Transport-Security | |
| X-XSS-Protection deprecated, not counted |
| Privacy policy /privacy | |
| Terms of service /terms | |
| Consent manager Google |
Mentions: Cookies, Do Not Sell
| robots.txt | |
| sitemap.xml | |
| security.txt | |
| llms.txt optional | |
| ads.txt only for ad-funded sites | |
| humans.txt optional |
| llms.txt published not published | |
| No AI bots blocked in robots.txt | |
| Content-Signal none declared | |
| Link headers none advertised |
| State | Record | Status |
|---|---|---|
| SPF ~all | Soft-fail (~all), common and accepted | |
| DMARC | Not published | |
| DKIM | Found | |
| MTA-STS | Not deployed | |
| TLS-RPT | Not configured |
Without DMARC, receivers fall back to their own rules for email that fails SPF.
Hosting and network
| Network | AMAZON-02 - Amazon.com, Inc., US AS16509, US |
|---|---|
| DNS | Google Domains DNS authoritative nameservers |
| DNSSEC | Not enabled DNS answers are unsigned |
| Certificate | Let's Encrypt valid 29 Oct 2026 to 27 Jan 2027, as captured |
| Domain age | 1 year registered Oct 2025, Squarespace Domains II LLC |
| Green hosting | No record per The Green Web Foundation |
| Page build | 34 JS files, 2 CSS files 1 third-party domain, code splitting |
| App manifest | Crux display standalone; 2 icons |
| Brand colours |
Storage: 4 items
| Name | Lifetime | Set by |
|---|---|---|
| __client | 1y | Clerk |
| __client_uat | 1y | - |
| __client_uat_7T6h-mZ9 | 1y | - |
| Key | Size | Set by |
|---|---|---|
| __clerk_environment | 6.8 KB | Clerk |
Performance
| Measure | This site | Reading |
|---|---|---|
| Server response | 201 ms | good, faster than 58% of sites |
| Largest contentful paint | 6,120 ms | slow |
| Layout shift | 0.00 | good |
| Page weight | 1.4 MB | fair |
| Image weight | 89 KB | light |
| Images | 33 | 22 larger than shown, 33 without width and height, 33 without alt text |
| Third-party domains | 1 | |
| Console errors | 0 | none |
| Failed requests | 0 | none |
From a single automated render of the home page. A quick guide, not a substitute for Lighthouse or field data. How we measure
Notes
-
Looks AI-built: some AI signals.
How much the site looks AI-generated. It is a pattern match shown for interest, not a verdict.
Which signals fired
Signal Points AI CSS signals +10 AI copy signals +5 AI palette signals +5 AI stack signals +10 - Performance comes from one render on 8 November 2026 and will vary between visits.
How we know
FirstSited records what new websites are built with, usually within a day of going live. Most we find ourselves, by watching public internet infrastructure for brand-new sites; the rest come from Product Hunt, Hacker News and PeerPush. We checked this one in full: its tech stack, DNS, security headers and page basics. This page is what we saw on 8 November 2026; the live site may have changed since.
Every technology below links to its own page: which other new sites launched with it. Watch any of them and get every new site that uses it as it goes live, from £15 a month.