读取世界的 level.dat 或玩家的 .dat 文件，并检查极限模式世界的状态，全部在浏览器中完成。
Your world file is read entirely in your browser and never uploaded anywhere. Always back up your world folder before replacing level.dat.
一整套在浏览器里运行的生成器、查看器和转换器，全部免费。