Version Details and Security Vulnerabilities

React 19.1.1 is a minor patch release following the 19.1.0 version, both building upon React's foundation as a leading JavaScript library for crafting user interfaces. While the core description and licensing (MIT) remain consistent, subtle differences emerge. The unpacked size, although negligibly different, goes from 167000 in version 19.1.0 to 166994 in version 19.1.1 which hints at potential under-the-hood optimizations or minor adjustments in the codebase, possibly involving removing some bytes. Most importantly, the releaseDate is different, with version 19.1.1 being released on "2025-07-28T14:55:41.076Z", four months after the the previous stable version.

For developers considering an upgrade, the key lies in understanding that 19.1.1 likely addresses specific bugs or edge cases encountered in 19.1.0. Therefore, users experiencing issues within their React applications might find 19.1.1 to be the more stable and desirable choice. Reviewing the detailed changelog or release notes accompanying 19.1.1 is essential to identify the precise fixes and improvements incorporated. Although the file count remains at 27 in both versions the tarball is different so it means that something was changed in the code. When dealing with patch versions a good measure would be to look at the commit history on github in order to uncover the changes that justify an upgrade. For new projects the team would recommend to use the latest version to have all the upgrades in place, ready for production.