Redirecting your entire domain will affect your SEO. Redirects will create a layer of friction between your old domain URLs and any backlinks you’ve historically received, effectively diluting your internal PageRank flow. Learn more about PageRank Flow:

Are 301 Internal Links Bad for SEO? – Fire&Spark 

If you redirect a subdomain or a subfolder, but keep your main domain intact, we strongly suggest you go and change all internal links to that subdomain or subfolder, otherwise there will be an unnecessary flow of internal 301 redirects that will likewise slow down your PageRank. If you choose to not redirect your domain and keep it up without a change, you will risk ranking losses, and even a bad user experience. Read more on why and how redirects in general can hurt your SEO:

Do Redirects Hurt SEO? – Fire&Spark 

We recommend only changing redirecting your domain when there has been a brand name change so the old domain no longer represents your business well. We don’t recommend changing your domain just for cosmetic purposes, for example – changing domain-name.com to domainname.com, or domainname.com to domainname.shop If you need to redirect your domain but are worried about your SEO performance suffering, we recommend reading Google’s guide on Site Moves & Migrations:

Site Moves and Migrations | Google Search Central | Documentation

If you’re still worried on how to handle the change, contact us. We can give you a free strategy consultation on how to do the most painless domain redirection for SEO, or onboard your business to assist you during your domain migration.