Best BuiltWith Alternatives in 2026: Installmap Ranked First

Seven BuiltWith alternatives, ranked on one test: can a buyer read a usable adoption number off the public site, with the population it is over and the date it was counted? We asked every source how many companies use HubSpot, Klaviyo and PostHog on 5 September 2026, without an account. Installmap is ranked first. It is the only source that printed the share, the denominator and the crawl date on the same page. BuiltWith itself served a bot challenge instead of a number, three routes running.

1. Installmap prints the share, the base and the date on one page

Installmap crawls named lists of companies as complete sets and publishes what share of each list runs each tool. For HubSpot on 4 September 2026 it reads: 1,252 of 4,885 crawled Inc 5000 homepages, 25.6%; 603 of 5,386 Y Combinator companies, 11.2%; 172 of 1,000 unicorns, 17.2%; 573 of 8,173 SaaS companies, 7.0%; 12 of 472 Fortune 500 homepages, 2.5%. Each page states how many domains on the list returned a usable record, splits that into rendered crawl, plain fetch and no record, and repeats the crawl date in the footer. A cite block gives the sentence to copy.

That is the number an outbound team needs first. Before buying any list, you want to know what fraction of the companies you actually sell to run the tool. If your buyers look like YC companies, HubSpot is on one in nine of them and PostHog on one in eight. If they look like the Inc 5000, HubSpot is on one in four and PostHog on one in fifty. No global count tells you that.

What Installmap does not do: it does not export a list and it does not sell contacts. It answers the sizing question and stops. For the list itself you go to one of the vendors below, or have one built.

HubSpot across the Inc 5000 on Installmap · PostHog across Y Combinator · method

2. PublicWWW states its index and its date, and counts pages

PublicWWW is a source code search engine. A search for js.hs-scripts.com returns 117,653 web pages, and the homepage states the index it searched: 524,927,560 pages on 3 September 2026. That is the only other source here where a reader can see what the number is out of. The unit is pages carrying the script, so an agency's fifty client sites count fifty times and nothing maps a page to a company. Free access covers the top 3M sites and 1,000 rows; Pro is $109 a month, Business $199, Enterprise $499, with CSV exports of 100k to 1M rows. No contacts.

What it lacks against Installmap: a company as the unit, and any named list to divide by.

3. TheirStack counts companies and sells the export, without a population

TheirStack's HubSpot page says "we have data on 229,488 companies and users that use HubSpot". It does not say how many companies it checked and carries no date. Under the headline the page breaks customers out by continent: 42,146, 24,258, 7,227, 1,948, 1,573 and 464, which add to 77,616, a third of the headline, and the page does not explain the difference. For PostHog it reports 3,054 companies against Wappalyzer's 310,000 websites.

Pricing is the clearest in the category: one-time company credits from 1,000 for $109 to 200,000 for $999, API plans from $49 a month, unused credits rolling over for twelve months, CSV and Excel export. Contacts are not on the pricing page. The job-postings side is worth testing for outbound: a company hiring people to run a tool is a stronger signal than a script on its homepage.

What it lacks against Installmap: a denominator, a date, and a breakdown that matches its own total.

4. Wappalyzer counts websites and attaches contacts

Wappalyzer says it "tracks 540,000 live websites using HubSpot", 200,000 for Klaviyo and 310,000 for PostHog. No population, no date. It is the only source in the test that puts PostHog above Klaviyo; every other one has Klaviyo ahead by 2x to 10x. Pro is $250 a month, Business $450, Enterprise $850 and up, 17% off annually; a free account gets 50 lookups a month. Lead lists come with emails and phone numbers and there is an email verification product, which is the practical reason an outbound team buys it.

What it lacks against Installmap: any statement of what 540,000 is out of, so no share of anything can be computed from it.

5. Enlyft prints the largest numbers and a share of an unstated category

Enlyft reports 1,001,024 companies using HubSpot, 421,204 using Klaviyo and 116,839 using PostHog, each with a "market share": about 2.1% of Enterprise Marketing Management for HubSpot. Divide the two and the category would hold roughly 48 million companies; the category size is not on the page, and PostHog is scored in a different category, so the shares cannot be set against each other. The HubSpot count is nearly double Wappalyzer's website count, so at least one of the two is counting something other than its label says. There is no pricing page; the list sits behind a demo request, and contact discovery is listed as a feature.

What it lacks against Installmap: a denominator for the share, a date, and a price.

6. NerdyData shows no count to a logged-out visitor

NerdyData searches the code of live sites, which makes it the right tool when the thing you want to target has no fingerprint of its own, such as a competitor's embed. But nothing is visible without an account: the technology pages render as "Browse 1000 technologies" with no counts. Plans are $200, $300 and $1,000 a month with 5,000 to 1,000,000 rows per download and contact details on domain lookups. It gives reports free to anyone publishing research that cites it.

What it lacks against Installmap: a public number at all.

7. SimilarTech could not be reached

The technology pages failed at the connection on a datacenter proxy, a rendered request, a residential IP and a stealth route on the test day, so nothing is recorded for it. It sells technology breakdowns and contact lists according to its own description.

BuiltWith answered with a bot challenge

The three BuiltWith trends pages returned the same verification page, an animal-image grid, on a datacenter proxy, a rendered request and a residential IP. We did not try to solve it. The plans page loaded first time: $295, $495 and $995 a month, or $2,950, $4,950 and $9,950 a year, with CSV export and contact names, emails and titles. BuiltWith states 491.9 million domains and 126,446 technologies on that page. Its history data is the reason to buy it; a free adoption number is not.

The test: one question, seven sources, answers 8.5x apart

Every row is what the source printed to a logged-out visitor. The unit column is the point: three sources count sites or pages, two count companies, one counts a share of a named list.

The same sources on Klaviyo and PostHog. For PostHog, TheirStack and Wappalyzer are 101x apart.

Prices, exports and contacts

How we use this on a client build

We size the segment on Installmap first, against whichever of its lists our client's buyers resemble, and only then buy or build the list from the vendor whose export and contacts fit. The failure we see most often is the reverse order: a team exports every company running a tool, then finds mid-campaign that the pool was a tenth of what the vendor count implied, because their buyers live in one list and the count was over the whole web. Our stack-based lists start from companies using Stripe, companies using Snowflake and SaaS companies, filtered to a client's ICP before anything is sent; the wider set is on the email lists page.

How we ran the test

All fetches on 5 September 2026 through a rotating proxy, with a rendered browser request where a plain fetch returned a challenge or a JavaScript shell. No accounts, no logins, nothing bought. Where a vendor did not print something, the cell says so. Installmap cells marked n/a fall under its publishing floor. Vendor facts are from each vendor's own pages that day; Installmap figures from its pages as of its 4 September 2026 crawl.