Download websites that use Heroku

About Heroku

Heroku is not where most of the web lives, and that is what makes the detected population interesting. Its customers are teams that chose to skip servers entirely: push a branch, let a buildpack work out the runtime, get a running application behind a URL. The platform arrived in 2007, was acquired by Salesforce a few years later, and the git push deployment model it popularised is now the default expectation almost everywhere, which means finding it today says something specific about a team rather than something generic about the industry.

A site on Heroku is usually an application rather than a brochure. Static marketing pages are cheaper to host elsewhere, so what accumulates on the platform is the other kind of web property: software as a service dashboards, customer portals, internal tools that grew a public login, API backends, and prototypes that acquired real users before anyone got around to migrating them. Detecting it is therefore a decent proxy for an engineering team small enough to value not running infrastructure and busy enough to accept the premium for it.

As of September 2026 we detect Heroku on 3,679 sites, a smaller number than the platform's reputation would suggest, and the gap has an explanation. Hobby projects left when the free tier was withdrawn, and workloads that grew past a certain size found Proprietary platform pricing harder to justify than raw cloud compute. What remains is a middle band of commercially real applications, which for most commercial purposes is the useful part of the population anyway.

Detection depends on what the platform exposes at the edge: default application hostnames, routing behaviour and response headers. An application sitting behind a content delivery network or a custom domain with its own proxy can hide the platform completely, and plenty of companies run marketing on one host and the product on Heroku under a subdomain we may attribute separately. The list is best understood as the visible half, weighted toward teams that never bothered to obscure where the app runs.

For a per domain question a lookup is enough. The reasons to want the whole set are different. Cloud and platform competitors use it to build migration target lists. Vendors of databases, queues, logging, error tracking and other add on services use it to find accounts already accustomed to buying infrastructure as a subscription. Security researchers use it to scope which organisations share a common failure surface. Investors and analysts use the population trend across snapshots to judge whether a platform is growing, holding or slowly emptying, and no single domain check can answer that.