steps to reproduce:
create a world (survival , CHEATS=OFF)
explore the world (to increase the world size)
save the world.(restart MC=optional)
check the world size.(mine 14.4MB)
change gamemode to creative,but do not accept it.
check again the world size.(mine 13.4MB)
These "extra data" are needed?
case YES: why delete them?
case NO: why save them?
Linked issues
Comments 7


Minecraft uses LevelBD to store data. This means size of world will fluctuate somewhat - i.e.original data written when exploring the world might not be in most space efficient format and is compacted later.

Thank you for your report!
We're actually already tracking this issue at MCPE-23462, so I will resolve and link this ticket as a duplicate.
That ticket has already been resolved as working as intended, which means this is not considered a bug and won't be fixed. Please do not leave a comment on the linked ticket.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki

Thank you for your report!
We're actually already tracking this issue at MCPE-23462, so I will resolve and link this ticket as a duplicate.
That ticket has already been resolved as working as intended, which means this is not considered a bug and won't be fixed. Please do not leave a comment on the linked ticket.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki

@unknown Please stop adding irrelevant or "instructional" comments to other reporter's tickets only to delete them later. Deleting comments makes the thread confusing.

@unknown Please stop adding irrelevant or "instructional" comments to other reporter's tickets only to delete them later. Deleting comments makes the thread confusing.

ok, I'm "STOP" commenting other issues.
NOTE: I deleted my comments if
the issue is resolved
if a MOD commented the issue.
the reporter doesn't reply
my "instructional" comment didn't help.
Minecraft uses LevelBD to store data. This means size of world will fluctuate somewhat - i.e.original data written when exploring the world might not be in most space efficient format and is compacted later.