YC W18 Batch — Full Company List and Overview

W18 is notable for its breadth across sectors — B2B dominated at 32.6%, followed by consumer (27%) and bio/healthcare (17.7%) — and for representing 24 countries, with 35% of companies coming from outside the US, one of the higher international proportions in YC's history to that point.

• Companies at demo day: 141
• Demo day date: March 19-20, 2018 (YC's 26th Demo Day)
• YC total funded companies at time: 1,585 since 2005
• International proportion: 35% of companies from outside the US
• Countries represented: 24 (Argentina, Australia, Brazil, Canada, China, Colombia, Egypt, Estonia, France, Germany, India, Indonesia, Latvia, Mexico, Netherlands, Norway, Russia, Singapore, Spain, Turkey, UK, Uruguay, USA, and others)
• Average founder age: 29.91 years
• Female founder representation: 27% of companies had at least one female founder

Sector Distribution (Verified from YC Demo Day Stats)

Verified W18 Companies Published by YC

YC published announcements of W18 companies across multiple blog posts. Confirmed companies from those official announcements include:

Security and Infrastructure:

Fintech and Payments:

Consumer and Marketplace:

Developer and Design Tools:

Agriculture and Deep Tech:

B2B Data and Intelligence:

Latin America Focused:

The Largest Demo Day in YC History (at that time)

W18's 141-company demo day was officially the largest in YC's then-13-year history, reflecting YC's steady batch size expansion through the 2015-2018 period. This represented significant growth from the 111-company W16 batch and the 125-company W17 batch, continuing a trend toward larger cohorts that would accelerate further in the 2019-2024 period.

International Founder Diversity

W18's 35% international proportion — covering 24 countries — was one of the higher international representations in YC history at that time. Latin America in particular was strongly represented, with multiple companies from Argentina, Brazil, Colombia, Mexico, and Uruguay addressing Latin American market problems specifically (Meitre for Latin American restaurants, Runa HR for Latin American payroll, Ropeo for Latin American e-commerce). This Latin American concentration in W18 reflected an early signal of the strong Latin American founder representation that continued growing through subsequent batches.

Bio and Healthcare at 17.7%

The healthcare and biotech proportion in W18 (17.7%) was notably high relative to adjacent batches, reflecting YC's growing commitment to funding hard science and health companies alongside software-first companies. This proportion would continue growing in subsequent years as YC leaned further into biotech and healthcare investment.

The Blockchain Category Emerges

W18 was one of the first YC batches where blockchain was an official named sector category at 3.5% of the batch — reflecting the late-2017 to early-2018 crypto enthusiasm that surrounded the batch period. Companies in this category faced a difficult subsequent 12 months as the crypto market corrected significantly through 2018.

Priority 1: Latin American markets as genuine primary targets

Multiple W18 companies were building specifically for Latin American users and markets — not as an expansion market but as the primary addressable opportunity. This represented an early signal of YC's thesis that the largest non-US emerging markets warranted primary rather than secondary investment, a thesis that became more explicit in subsequent years.

Priority 2: AR/VR design tools at the height of the hype cycle

Two W18 companies (Haiku and Sketchbox) addressed the AR/VR development and design space that was generating significant investor enthusiasm in early 2018. Both faced headwinds as the AR/VR consumer adoption curve proved slower than the hype suggested, illustrating how batch composition often reflects the prevailing technology enthusiasm of the application period.

Priority 3: Agricultural technology as a genuine deep tech category

Ovipost's inclusion in W18 — addressing insect farming efficiency for alternative protein — reflected YC's growing interest in deep tech and climate-adjacent categories that required significant technical innovation rather than purely software solutions.

Priority 4: The female founder representation push

W18's 27% female founder company rate (23% of applicants had a female founder, and 16% of all founders were women) represented a meaningful point in YC's ongoing effort to improve female founder representation, reflecting deliberate outreach and application encouragement efforts YC had been building over multiple years.