Vercel hosts 51% of the newest YC batches, up from 8% in 2012-17

Key findings

1. Vercel is on 50.8% of the YC companies in the 2025 and 2026 batches and on 8.2% of the companies in the 2012 to 2017 batches.
2. Cloudflare went the other way over the same batches, from 48.3% down to 29.7%.
3. Netlify never passes 3.5% in any of the three blocks, so Vercel's gain did not come out of it.
4. PostHog is the only analytics brand that grew, from 2.6% of the 2012 to 2017 batches to 19.7% of the newest two.
5. Google Analytics 4 is on 22.6% of the newest batches, down from 52.0% of the 2022 batch.
6. Cal.com is on 4.0% of the newest batches against Calendly's 1.7%.

Vercel's move across batch years is the biggest any named brand makes in our crawl. We expected the gain to come out of Netlify, since the two sell the same kind of hosting to the same kind of company. Netlify never held enough of the pool for that. What Vercel took came from Cloudflare and from companies that would once have run their own server.

Vercel is on 50.8% of the 2025 and 2026 batches and Cloudflare on 29.7%

Vercel's rise is steady rather than a jump. It reaches 37% of the 2023 batch, 40% of 2024 and 52% of 2026. Cloudflare and Vercel can both show on one domain, so the columns do not add up to 100%.

Google Analytics 4 is on 22.6% of the newest batches and PostHog on 19.7%

PostHog is the only analytics brand that grew, and it peaks at 23% of the 2025 batch on its own. We expected the companies it won to be Mixpanel and Amplitude customers, but both of those were already small in the old batches. What PostHog replaced was Segment and a plain Google tag.

Framer is on 8.9% of the 2025 and 2026 batches and Webflow on 3.7%

Webflow did not decline steadily. It peaked at 28% of the 2020 batch, held its share through 2022, then fell to 5.6% of 2025 and 1.9% of 2026. Framer picked up the batches in between, 12% of 2023 and 15% of 2024, and then fell back to 5.5% of 2026. WordPress does not reach five companies in the two newest batches.

Intercom is on 0.6% of the newest batches and no other chat widget clears the floor

No widget took the share Intercom lost. Every chat brand we fingerprint falls across the three columns, and four of the five do not reach five companies in the newest batches. Most of the newest sites carry no chat widget at all.

Cal.com is on 4.0% of the 2025 and 2026 batches and Calendly on 1.7%

Cal.com is now ahead of Calendly, and the gap is wider in the 2026 batch on its own, 4.7% against 1.1%. Calendly peaked in the 2022 batch and has given back most of that since. Cal.com is on no YC homepage before the 2019 batch.

Ashby is on 2.4% of the newest batches and is the only recruiting brand above the floor

Greenhouse and Lever are both under five companies in the newest batches, so read this table as a direction and not as a ratio. A company that runs its jobs page on a subdomain leaves nothing on the homepage for us to score, so every number here is a floor.

Data funnel

We can prove those five steps and no more. The crawl outputs record how many domains were dropped, not why each one was dropped: the render logs hold per run totals of pages that came back and pages that did not, and the plain fetch failure log covers the plain crawl rather than the merged set. So the split of the dropped domains between dead domains, blocks, timeouts and pages with nothing to score is unrecorded, and we do not print one.

How we counted

We crawled 6,133 YC company homepages on 2026-09-04 in a headless browser and scored 5,386 of them, of which 5,175 fall in the 2012 to 2026 batch years. We keep one record per domain, the rendered one where we have it and a plain fetch otherwise. Two floors apply. We do not print a share on a base under 20 crawled domains, and every per year base here is at least 69; we do not print a share for a tool with fewer than five installs in a block, which is what a cell reading "<5" means. We only see the homepage, so anything behind a login, at a checkout, on a subdomain or running on the server leaves nothing for us to score. This is one crawl on one day and not a panel, so we never watched a company switch anything, and a 2014 company running Webflow may have put it there at any point since. The batches also differ in age: sites in the 2026 batch are weeks old and many are a single launch page, which pulls down every marketing and support tag in the newest column at once, so the falls in the chat and scheduling tables are softer than they look.

Dataset

The per year counts and shares behind every cell are published under /static/data/yc-stacks-by-batch/ as data.csv, a README.md listing the columns and denominators, and a METHOD.md covering the crawl date, the fetch method, the floors and the funnel. Data: CC BY 4.0, Installmap, 2026-09-04. Next to any number here, cite: Source: Installmap, September 2026.