How do concurrent builds work?

I am considering moving my infra over to Netlify from AWS, but I have a small concern. I have about 100 sites that all build from the same repository. An env variable tells the build what to change in each web site. I see that the business plan offers 5 concurrent builds. Does this mean that if all 100 sites begin trying to build that it will queue 95 of them, and as the builds complete it will build one by one? I am asking because I am not sure if concurrent builds means Netlify will let you exceed but charge you $$ for exceeding.

Hiya @Abbi and sorry to be slow to get back to you!

5 concurrent builds means “we’ll be building 5 sites concurrently for you until the queue empties”. You can watch it in real time in the UI (well, the deploys listing pages only reload once a minute, but you can reload between then to see current status) to confirm this.

There is no additional charge beyond the plan price for any plan - Starter, Pro, or Business - to queue up builds beyond your concurrency limit. You’ll just get through your 100 builds 3 or 5 times faster on the higher plans :slight_smile: