For Business Class teams, the team export will export a zip file of all team boards in json and csv, as well as attachments in their native format: https://help.trello.com/article/992-the-team-overview#export
For free teams, there's a third-party resources that will allow you to export all attachments from a Trello card. While we're not able to endorse any third-party apps (since we don't work with them directly), you can check it out here: https://trello-downloader.xiat.net/
Hello Community! My name is Brittany Joiner and I am a Trello enthusiast and Atlassian Community Leader. I'll be sharing with you a series of videos with my top tips on how to best use Trello...
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