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21st.dev

21st.dev

Private
San Francisco, CaliforniaEnterprise Softwarehttps://21st.dev/home

Last Round

Accelerator

Mar 16, 2026

Total Funding Raised

$1M

Momentum

Top 25%

of companies Caplight tracks

Company Overview

21st.dev is a software development applications company that provides an infrastructure and UI component registry for building and deploying AI agents.

Sector

Enterprise Software

Verticals

DevOps & Containers, Low-Code/No-Code

Business Model

B2B

Customer Profile

Subscription SaaS, Freemium

AI Layer

Application

Keywords

react componentsui component libraryfrontend developmentcomponent registryvibe codingcli toolui code snippetsai coding assistantdeveloper toolssubscription saascode reuseweb application developmentui ux engineering

Historical Pricing

Historical view of private secondary pricing and transaction trends.

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Caplight Momentum Score

Proprietary index based on bid/ask volume and sentiment.

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21st.dev Comparables

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21st.dev comparables — related companies by embedding similarity
CompanySimilarityMarket Cap
Vercel
70%
StackBlitz
64%
Thesys
56%

21st.dev Funding Rounds

Historical fundraising activity

Data table
RoundDateAmount RaisedValuationInvestorsSources
AcceleratorMar 16, 2026
AcceleratorJan 1, 2026

Key People

Founding team and executive leadership

Serafim Korablev

Co-founder, CEO

Founding Team

21st.dev Investors

Notable investors and investment history

21st.dev investors
InvestorRounds
Pioneer FundAccelerator
Transpose Platform ManagementAccelerator
AloniqAccelerator
AAL VCAccelerator
Y CombinatorAccelerator
Hustle FundAccelerator

Market signals

Structured signals derived from secondary market and firmographic data.

  • Apr 18, 2026

    Monthly visitors increased 123% MoM, reaching 1.7 million.

  • Mar 16, 2026

    $500K round led by Y Combinator.

21st.dev Filings

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21st.dev filings preview — column headings only; records require access
TypeDateAmount OfferedAmount SoldFilingPagesDownload

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Firmographic Details

HeadquartersSan Francisco, California
Employee Range6
Year Founded2024
Last FundingMar 16, 2026

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