Purpose The purpose of this paper is to analyse the metrics provided by Publons about the scoring of publications and their relationship with impact measurements (bibliometric and altmetric indicators). Design/methodology/approach In January 2018, 45,819 research articles were extracted from Publons, including all their metrics (scores, number of pre and post reviews, reviewers, etc.). Using the DOI identifier, other metrics from altmetric providers were gathered to compare the scores of those publications in Publons with their bibliometric and altmetric impact in PlumX, Altmetric.com and Crossref Event Data. Findings The results show that: there are important biases in the coverage of Publons according to disciplines and publishers; metrics from Publons present several problems as research evaluation indicators; and correlations between bibliometric and altmetric counts and the Publons metrics are very weak (r<0.2) and not significant. Originality/value This is the first study about the Publons metrics at article level and their relationship with other quantitative measures such as bibliometric and altmetric indicators.