Does Amazon S3 need time to update CORS settings? How long?

Question

Recently I enabled Amazon S3 + CloudFront to serve as CDN for my rails application. In order to use font assets and display them in Firefox or IE, I have to enable CORS on m

Answer 1

To answer the actual question in the title:

No, S3 does not seem to take any time to propagate the CORS settings. (as of 2019)

However, if you're using Chrome (and maybe others), then CORS settings may be cached by the browser so you won't necessarily see the changes you expect if you just do an ordinary browser refresh. Instead right click on the refresh button and choose "Empty Cache and Hard Reload" (as of Chrome 73). Then the new CORS settings will take effect within <~5 seconds of making the change in the AWS console. (It may be much faster than that. Haven't tested.) This applies to a plain S3 bucket. I don't know how CloudFront affects things.

(I realize this question is 6 years old and may have involved additional technical issues that other people have long since answered, but when you search for the simple question of propagation times for CORS changes, this question is what pops up first, so I think it deserves an answer that addresses that.)