When I play online on the Java Edition games it runs reasonably smoothly when I go into single player mode it doesn't run smoothly all the time. Do you have any ideas why this is so?
Bad hardware?
@picasso no it won't be because of that
Try the chunk loader down to basket or other graphics settings down
or try optifine
Turn down the chunks and install Optifine.
The chunks are preset and limited on some servers, but there's no limit in the single player.
So try to turn down the chunks.
Put down the chunks, that's otherwise limited on the server side. You can also download Optifine.