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PostHog is on 12.8% of YC homepages and 1.8% of the Inc 5000: the analytics tool founders pick and older businesses skip

Installmap, 2026-11-09 · Download PDF

PostHog loads on 692 of the 5,388 Y Combinator homepages we crawled (12.8%) and on 86 of 4,888 Inc. 5000 homepages (1.8%). PostHog went through YC itself in 2020, so some lead in its own network was expected. The size of the lead was not: in YC it is on more homepages than Mixpanel, Amplitude and Heap put together, by 692 to 190.

PostHog and the other product analytics tools by company list

Source: Installmap, homepages crawled in September 2026.

List Homepages PostHog Mixpanel Amplitude Heap GA4 Clarity
Y Combinator 5,388 692 (12.8%) 102 54 34 2,227 (41.3%) 422 (7.8%)
Inc. 5000 (2026) 4,888 86 (1.8%) 26 10 18 3,241 (66.3%) 918 (18.8%)
Unicorns 1,000 15 (1.5%) 17 23 17 560 (56.0%) 128 (12.8%)
Fortune 500 472 1 (0.2%) 0 0 2 207 (43.9%) 44 (9.3%)

The Inc. 5000 runs on Google Analytics 4 (66.3%) and Microsoft Clarity (18.8%), both free. PostHog still leads Mixpanel, Amplitude and Heap there, but the whole category is small.

The unicorns surprised me. These are mostly venture backed software companies, the closest thing to grown up YC startups, and PostHog is behind Amplitude, Mixpanel and Heap among them. The 15 that load it include Tekion, Tenstorrent, SiFive, Scandit, Hasura, Timescale, MX, Immutable, Offchain Labs and Enpal. Only one of the 15, Mashgin, is a YC company. In the Fortune 500 the one homepage with PostHog is Fastenal's.

Newer YC batches use it more

YC batch year Homepages PostHog Share GA4 Share
2019 and earlier 1,594 56 3.5% 719 45.1%
2020 to 2021 987 103 10.4% 510 51.7%
2022 to 2023 1,008 169 16.8% 504 50.0%
2024 to 2025 1,157 258 22.3% 375 32.4%
2026 642 106 16.5% 119 18.5%

In the 2024 and 2025 batches more than one homepage in five loads PostHog, while Google Analytics 4 falls from about half of homepages to a third. In the 2026 batches the two are close, 16.5% against 18.5%. Those homepages load less of everything, so the 2026 row is the least settled.

Within YC, the companies selling to other businesses lead: PostHog is on 469 of 2,795 B2B homepages (16.8%), against 9.9% in fintech, 9.3% in consumer, 7.1% in healthcare and 3.8% in industrials. Active companies load it on 15.5% of homepages, inactive ones on 3.2%.

In the Inc. 5000 it is not about size

The 86 Inc. 5000 companies with PostHog spread evenly across employee bands: 6 with 1 to 10 staff, 41 with 11 to 50, 27 with 51 to 200, 9 with 201 to 500 and 3 with 501 to 1,000, between 1.4% and 2.0% of each band. 10 are software companies and 10 are in advertising and marketing. The rest is a mixed list that includes Churnkey, Attentive.ai, Atticus, Fulfill.com, Corelight, Harbor Compliance and two plumbing and HVAC firms, Anchor Heating and Air and Cardinal Plumbing Heating & Air. Four of the 86 are YC companies: Optery, Shepherd, Solo and Tractian.

Company size does not explain the gap, then. My guess is the person who sets up analytics: in a YC startup that is often a technical founder, and PostHog markets to developers.

How we counted

PostHog counts when the homepage calls posthog.init( with a project key or loads a script from a PostHog host. We counted what the homepage loads on a first visit with no consent given. Many teams install PostHog only inside their product, so every number here is a lower bound, and probably more so for PostHog than for Google Analytics.

Dataset

group_counts.csv, yc_by_batch_year.csv, README.md, METHOD.md

Cite this

Installmap, PostHog is on 12.8% of YC homepages and 1.8% of the Inc 5000: the analytics tool founders pick and older businesses skip, 2026-11-09, https://installmap.com/research/posthog-yc-vs-inc-5000.

Groups referenced

Tools referenced