How often should I backup my WordPress site?

How often should I backup my WordPress site?   

every week There's no one-size-fits-all answer for every single website. If you have a static website that doesn't change very often (e.g., a portfolio site), you might be fine with backing up your site's data every week. In general, weekly backups should be the bare minimum for most WordPress sites.

if it is an online shop, then every day.