21st was founded by Serafim Korablev, Sergey Bunas in 2024.

Who are 21st's investors?

21st's investors include Aloniq, Pioneer, TRAC (Third Round Analytics Capital), Transpose Platform Management, Y Combinator, AAL VC, AltaIR Capital, Blast.Club and 7 more.

Where is 21st headquartered?

21st is headquartered in San Francisco, US.

21st

YC W26

San Francisco, US · Founded 2024 · 3 employees · 16 known investors

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21st.dev provides a library of thousands of components and templates from the community for developers to use in building applications.

Also known as 21st Labs Inc. · 1code (21st.dev) · 1code (ex: 21st.dev) · 1code by 21st.dev · 21st, 1code by 21st.dev, 1code (21st.dev), 1code (ex: 21st.dev), 1code (21st.dev), 21st.dev · 21st.dev

Developer Tools Enterprise SoftwareUnited States of AmericaAmerica / CanadaPartly Remote

Founders & leadership· Y Combinator alumni (W26)

21st was founded in 2024 by Serafim Korablev and Sergey Bunas.

Serafim Korablev Co-founder, CEOSerafim Korablev co-founded 21st.dev, a UI components registry, and previously co-founded Rork.com (a web app builder for Next.js), a Telegram-native memecoin launchpad, and Via, a cross-chain crypto routing protocol. He has been working full-time on product design since October 2023.

Sergey Bunas Co-FounderSergey Bunas is a computer science dropout who previously worked as a Senior Software Engineer at Deel. He built Suggesty, a search product launched in 2022, and Stage, a design tool that reached 10K users before joining his current venture.

Investors · 16

Aloniqlisted by Aloniq

How we know: Aloniq's portfolio page · Y Combinator's founder network · Not right? Tell us

Pioneerlisted by PioneerToronto, Ontario

How we know: Y Combinator's founder network · pioneerfund.vc · open dataset · 5k.vc investor directory · Not right? Tell us

TRAC (Third Round Analytics Capital)listed by TRAC (Third Round Analytics Capital)San Francisco · $250K – $2Mvia Fred Campbell · inferred

How we know: Y Combinator's founder network · Not right? Tell us

Transpose Platform Managementlisted by Transpose Platform ManagementSan Francisco

How we know: Transpose Platform Management's portfolio page · Y Combinator's founder network · Not right? Tell us

Y Combinatorlisted by Y CombinatorSan Francisco · $500K

How we know: the Y Combinator directory · open dataset · 5k.vc investor directory · Not right? Tell us

AAL VCreportedPort Moody

How we know: Y Combinator's founder network · Not right? Tell us

AltaIR CapitalreportedHerzliya

How we know: Y Combinator's founder network · Not right? Tell us

Blast.Clubreported$5.5M

How we know: Y Combinator's founder network · Not right? Tell us

Exit Venturesreported

How we know: Y Combinator's founder network · Not right? Tell us

Hustle FundreportedSan Carlos · $150K

How we know: Y Combinator's founder network · Not right? Tell us

Interface FundreportedSan Francisco · $1M – $10M

How we know: Y Combinator's founder network · Not right? Tell us

M2VCreported

How we know: Y Combinator's founder network · Not right? Tell us

OurCrowdreportedJerusalem

How we know: Y Combinator's founder network · Not right? Tell us

s16reportedLos Altos Hills

How we know: Y Combinator's founder network · Not right? Tell us

Tekedia CapitalreportedLagos · $1K

How we know: Y Combinator's founder network · Not right? Tell us

Also in the syndicate · 1

FPV Ventureslead

Funding

SEC filings, press & company announcements

Undisclosed amountSeries AFeb 2026
FPV Ventures (lead)
Source ↗

Source: company announcements and press reports — follow each round's link for the claim.

Images

Related companies · 7

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Firefox,Mozilla is a global community organization that develops and maintains open-source internet infrastructure, including the Firefox web browser and Thunderbird email client, while advocating for internet openness, privacy, and user control. The organization also invests in responsible technology startups and creates open-source AI tools for developers.

Companies working in the same space as 21st.

Legal entities · 1

corporate structure

21st Labs Inc.

In the news

21st - Infrastructure for AI agentsycombinator.com · Mar 2026

Frequently asked questions

What does 21st do?: 21st.dev provides a library of thousands of components and templates from the community for developers to use in building applications.
Who founded 21st?: 21st was founded by Serafim Korablev, Sergey Bunas in 2024.
Who are 21st's investors?: 21st's investors include Aloniq, Pioneer, TRAC (Third Round Analytics Capital), Transpose Platform Management, Y Combinator, AAL VC, AltaIR Capital, Blast.Club and 7 more.
Where is 21st headquartered?: 21st is headquartered in San Francisco, US.