Download websites that use Akka HTTP

About Akka HTTP

A backend service normally tells the outside world nothing about itself, which is why an HTTP toolkit turning up in a survey of websites is worth a moment of attention. Akka HTTP appears because a server that answers requests has to send response headers, and the header it sends can name the toolkit and its release. Detection here is not an inference drawn from page markup. Detection is a server introducing itself by name.

Header identification is optional, and the consequence of that runs through everything else on this page. Operators put reverse proxies in front of application servers, rewrite or strip the header, or terminate at a CDN that answers in its own name. Every one of those choices removes a host from our count without removing the toolkit from the stack. As of October 2026 we see 17 sites, and the figure should be read as a floor for public facing deployments and as no measure at all of internal services, which are a large part of what a JVM HTTP layer is used for.

Where the header does survive, the signal is unusually informative. A public endpoint answering under this name implies a shop that chose Scala on the JVM and an asynchronous, streams oriented design rather than a conventional servlet stack, and it more often fronts an API than a page rendered for a browser. None of that is a neutral fact about a company. Hiring, build tooling, monitoring and the kind of contractor a business brings in all follow from an architectural choice of that size, which is why the toolkit behind an endpoint is commercially useful to know.

Our version field holds 10.2.10, drawn from 8 distinct release strings observed across the population. A spread that wide over a base that narrow says something concrete about how the toolkit is consumed. A library compiled into an application is not patched by a package manager on the host. Upgrading means bumping a dependency, rebuilding and redeploying a service that somebody has to own, so releases accumulate in production and stay there for years. Compare that with a packaged web server, where a distribution upgrade sweeps a whole fleet onto one release at once.

The rest of the record is straightforward. Akka HTTP is Web frameworks published by Lightbend, first released in 2014, and we record the licence as Apache 2.0. Licensing around this wider ecosystem has moved over the years, so a buyer making a compliance decision should check the terms attached to the specific release found on a specific host rather than trusting a single field on any directory page, ours included.

Teams selling JVM tooling, observability or commercial support into Scala shops need the population. So do security researchers who want every host running a release range named in an advisory, and analysts sizing this stack against its alternatives. A per domain lookup answers whether one host you already suspected runs the toolkit. Whatever the answer, a lookup cannot hand you the hosts you did not know to ask about, and that is the whole population question. The downloadable file can, with the version string attached to each row where we captured one, so a version slice becomes a filter rather than a research project.