Sorting the Babble in Babel: Assessing the Performance of Language Detection Algorithms on the OpenAlex Database

Following a recent study on the quality of OpenAlex linguistic metadata (C\'espedes et al., 2025), the present paper aims to optimize the latter through the design, use, and evaluation of various linguistic classification procedures based on the latest and most efficient automatic language detection algorithms. Starting from a multilingual set of manually-annotated samples of articles indexed in the database, different classification procedures are then designed, based on the application of a set of language detection algorithms on a series of corpora generated from different combinations of textual metadata of indexed articles. At sample level first, the performance of these different procedures for each of the main languages in the database is evaluated in terms of precision, recall, and processing time. Then, overall procedure performance is estimated at the database level by means of a probabilistic simulation of harmonically aggregated and weighted scores. Results show that procedure performance strongly depends on the importance given to each of the measures implemented: for contexts where precision is preferred, using the LangID algorithm on article titles, abstracts as well as journal names gives the best results; however, for all cases where recall is considered at least slightly more important than precision or as soon as processing times are given any kind of consideration, use of the FastSpell algorithm on article titles only outperforms all other alternatives. Given the lack of truly multilingual, large-scale bibliographic databases, it is hoped that these results help confirm and foster the unparalleled potential of the OpenAlex database for cross-linguistic, bibliometric-based research and analysis.