The need to provide evidence of the content published in some web pages is becoming increasingly common for parties who are involved in a lawsuit, and wish to support their claims. This task, because of the fickle nature of Web content, may be difficult if the aim is to prove the existence of an older version of a specific web page.
To avoid this difficulty, the US organization Internet Archive provides a service called WayBack Machine (https://web.archive.org/), which enables users to access and see the different versions of a web site over time.
This "time machine" works as an internet archive that stores all the changes made in web pages, thus saving full copies of multiple URLs, including any uploaded documents and images that appear in them. Users only need to access the WayBack Machine portal, introduce the web page address as well as the date of the content they wish to see.
This tool has already been admitted in many jurisdictions as evidence. In fact, Spanish courts have viewed it favourably and have recognized the validity of the certificates issued by WayBack Machine.
Proof of this is the sentence issued on 31 May 2019 by the Provincial Court of Zaragoza (Rec. 763/2018). In this sentence, the Provincial Court of Zaragoza determined that WayBack Machine was a suitable tool to confirm the content of an older version of a web page. It is suitable because it is impartial (it has no links to the parties involved in the proceedings), it is free to use (which excludes any kind of financial interests) and it is automatic (avoiding any potential tampering).
Similarly, the Provincial Court of Barcelona, Section 15th, in its sentence issued on 12 March 2018 (Rec. 397/2017), wholly validated the certificate issued by WayBack Machine, which provided full proof in the proceedings in accordance with article 326 of the LEC.
However, and taking into account the particularities of each case, it may also be useful to submit a notarial certificate together with the WayBack Machine certificate, which would confirm that a notary has verified a web page using the WayBack Machine web portal.
In any event, a WayBack Machine certificate could be, based on the nature of the case and the claims that the parties wish to prove, a very useful and relevant tool.