Introduction. This paper analyses the level of development of the press archives of the thirteen Spanish newspapers with the largest digital circulations. Method. This is evaluative research based on twenty indicators divided into four main sections: general features, the query system, presentation of results and other features. The benchmarks for all the indicators were the Lexis-Nexis, Factiva and My News databases. Analysis. The press archives of online newspapers were analysed to determine their level of development and the search and browsing facilities they offer according to a set of quality indicators satisfied by professional press databases. The sample consisted of the thirteen newspapers with the largest circulations according to the figures provided by the organisations that audit the Internet press audience. The analysis was carried out from June to August 2007. Results. The level of development of digital press archives is not homogeneous. Of the newspapers studied, five showed a high or medium-high level of development, though not as high as that of the best commercial products. These were La Vanguardia, ABC, El País, El Mundo and El Periódico, all of which are online versions of prestigious general information newspapers published in print format. Seven newspapers showed a low or medium-low level of development. These were three daily sports papers (As, Sport, Mundo Deportivo), three exclusively digital newspapers (Periodista Digital, 20 Minutos and Libertad Digital) and one regional newspaper (La Verdad). Finally, one sports paper (Marca) had no search system by keywords. Conclusions. Fewer than half of the major Spanish newspapers show high or medium levels of development of their digital press archives, though not as high as that of the best press databases, and the rest are still far from satisfying the requirements of a professional search system. The indicators established may also be useful for analysing the situation in other countries