The Evidence Synthesis Hackathon’s online Evidence Synthesis & Meta-Analysis in R Conference (#ESMARConf) was held on January 21st and 22nd 2021. A total of 39 presentations, 10 panel discusisons and 4 workshops covered a wide variety of different tools and use cases for evidence synthesis and meta-analyses in R. 514 people registered for the conference, and so far >1,100 unique viewers have watched the conference videos, totalling over 4,100 views. All of the individual talks, panel discussions, workshops and livestreams are available for free on the ESMARConf2021 YouTube Channel. The conference is not only relevant for people developing packages, but also experienced and novice R users wanting to know what might be available. Find out more at the ESH website: https://www.eshackathon.org/events/2021-01-ESMAR.html.