Google has this week launched a free tool to help all media sites and and other organisations protect themselves against Distributed Denial of Service (DDoS) attacks.

First announced in 2013, the Project Shield initiative allows websites to redirect traffic through Google’s existing security infrastructure, in order to keep their content online in the face of a DDoS attack.

Google said that its initial aim is to work with smaller sites which do not necessarily have the money or are not fully equipped with strong enough infrastructure to surmount such attacks. However, the Shield tool has also been made available to larger outlets, such as popular news sites and human rights platforms.

Forming part of Google’s Jigsaw division, tasked with designing anti-corruption products, the team announced: “Project Shield welcomes applications from websites serving news. Human rights and elections monitoring content are also welcome to apply. We do not provide the service to other types of content, including gaming, businesses or individual blogs.”

In order to be accepted into the programme, websites are required to give Google access to detailed traffic information. Visibility over this data will allow the web giant to distinguish malicious traffic via an intermediate reverse proxy server. Google will keep the information for a fortnight, before adding it to an aggregated pool of anonymous data to be used for analytical purposes.

“Project Shield only uses the data we obtain (such as logs from the Project Shield servers) for DDoS mitigation and caching and to improve the Project Shield service,” the company added.

Jared Cohen, president of Jigsaw and advisor to the executive chairman at Google’s parent company Alphabet, said that two years’ of testing had proven Shield’s success. He explained that the project had managed to keep websites online during attacks, and that the team had been able to learn about the different types of attack in order to help improve mitigation services for the future.