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21st.dev

Infrastructure and UI building blocks for the agentic internet

Winter 2026 cohort
Traffic Rank#2
Attention Rank#2
Fundraising Rank#1
YC Profile|Shootout Compare||
Monthly Visits
2.08M
+0.8%
Avg. Duration
4:41
per session
Pages / Visit
5.22
engagement depth
Bounce Rate
38.06%
exit rate
YC Cohort
YC Winter 2026
B2B
Team Size
3
headcount
Domain Age
< 1 year
3/30/2026
Investor attention read

Durable pull

Compare cohort peers and ask where direct usage is compounding.

Overall74compound score
Quality80duration + pages
Loyalty6059.4% direct
LLM proxy10.0%1.5M weighted min

Verified Traffic Trend

Aug 2025Jan 2026Jul 2026
9 Months Locked

Channel Mix

Direct59.4%
Organic Search25.4%
Email0.8%
Social6.6%
Traffic Rank in Winter 2026 cohort
#2 / 198
Top 1%
Attention Rank in Winter 2026 cohort
#2 / 198
Top 1%
Fundraising Rank in Winter 2026 cohort
#1 / 198
Top 1%

AI Visibility

OpenAI GPTBotAllowed & Crawled
Anthropic ClaudeBotAllowed & Crawled
Google-ExtendedAllowed
Citation Score
76/100
AI Referrals
104.0K

Tech Stack

React
PostHog
Stripe
Cloudflare
Tailwind CSS
TypeScript
Vercel
Google Analytics

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