Keep items in inventory on death in Minecraft

You can use the command /gamerule keepInventory true (case sensitive) to prevent the player from losing items on death. This command will work in Vanilla Minecraft, without using any mods (as long as cheats are enabled). You can also do this on a server as long as you have operator status.

Use /gamerule keepinventory true. This'll make you keep your inventory when you die.

As mentioned before, you need to have cheats enabled, and you need to have the permissions to execute them.

Assuming you're in creative and have cheats enabled:

• Enter the command /gamerule keepinventory
• (Enter command /gamemode survival or /gamemode adventure) --> Takes you out of Creative

And you're done.

Assuming you're in Survival:

• Hit pause, and click open to LAN.
• On the next screen, set "Allow Cheats" to "ON."
• Enter the command /gamerule keepInventory
• Save and Exit.
  When you re-open your map, items will stay in your inventory after you die.