ACF version 5.0 landed on WordPress.org this week with Gutenberg compatibility now available for more than one million sites where the plugin is active. The release is a welcome update for developers who were concerned about what would happen in real world usage of Gutenberg on sites with ACF-powered customizations. ACF’s Gutenberg compatibility is arriving well ahead of WordPress 5.0’s TBD schedule for merging the new editor, giving developers time to get their clients’ sites ready.
“You can expect to see lots of Gutenberg related items in our changelogs over the coming months as we edge nearer to WordPress version 5.0,” the ACF announcement stated. “You’ll also want to take note that ACF 5 is the only version that will provide Gutenberg support. Previous versions will not be compatible.”
The version numbers across ACF Pro and the free version on WordPress.org are somewhat confusing. This particular release is significant in that it brings several years of development from the Pro version into the plugin hosted on WordPress.org. Now both products are technically on v5.7.6.
Hi guys. This version 5 release is for our “free plugin” on https://t.co/V7oUQSI5Ei and does not affect ACF PRO. Now both ACF and ACF PRO are v5.7.6!
— Advanced Custom Fields (@wp_acf) September 17, 2018
ACF 5.0 introduces a redesigned UI, performance improvements, and the plugin’s new Local JSON feature, which saves field group and field settings as .json files within the user’s theme. This reduces database calls and allows for version control of field settings.

Version 5.0 adds six new fields, including a link, group, accordion, oEmbed, date time picker, and clone fields (an ACF pro feature). It also introduce a new Tools page where users can export and import field groups as JSON.
For more information on items related to upgrading ACF and add-on compatibility, check out the official 5.0 release post.
Well this is a welcomed update as well seems pretty slick, but I am more pleased about the Json feature.