This data pack uses methods from server software like Spigot and Paper to optimize performance. You can configure many settings and even enable a small anti-crash for your server.
Use /function clearlag:menu to modify settings, view clear statistics and configure which clear/warning messages are shown.
The data pack was created with the aim of being high-performing and efficient, and should not cause any lag on its own.
Works on vanilla, bukkit, spigot, paper, all forks of paper and modded servers.
Note: You should always prefer server software such as Paper as it has a lot more customizable options and overall performance that data packs can never reach. You should only use this data pack if you have to use vanilla or you still have a lot performance issues.
Originally made by E4ry, modified with their permission: ClearLag Datapack

This anti lag data pack allows you to improve your vanilla servers performance a lot, while having many configuration options.