Stutters and Lag

Short freezes even when your FPS number is high: what causes them and how to make them go away.

FPS

A stutter is a single long frame: the counter can say 300 FPS while the game visibly hitches. Different causes, different fixes:

You noticeLikely causeFix
A hitch every few seconds, steadyJava cleaning up memoryKeep memory at 4 to 6 GB, not more; try Run on Java 25 on a slower CPU.
Freezes when you turn or move fastNew chunks being builtLower render distance a little; on Balanced or Extreme mode Sour trims more.
Freezes when a resource pack or shader loadsThe pack loadingNormal once. Shader packs take longer the first time.
Spikes only on a serverNetwork, not your PCCheck Ping and TPS. A rising ping or falling TPS is the server or your connection.
Stutters in the backgroundAlt-tabbedDynamic FPS (in the pack) lowers the frame rate while unfocused on purpose.
Recording or streaming at the same time? The encoder competes with the game for the GPU. Use your GPU's hardware encoder (NVENC, AMF or Quick Sync), not x264.