Note: Unless you are using a severely outdated operating system or CPU, you most likely want to always download the x64 (64-bit) version of Ultimate Doom Builder.
The 64-bit version has less limitations on the total size of the project that you can load and edit, while the x86 (32-bit) version of Ultimate Doom Builder only exists for compatibility with older PCs.
If not sure, follow these instructions to find out whether your system is 64-bit: Which version of Windows operating system am I running?
The 64-bit version has less limitations on the total size of the project that you can load and edit, while the x86 (32-bit) version of Ultimate Doom Builder only exists for compatibility with older PCs.
If not sure, follow these instructions to find out whether your system is 64-bit: Which version of Windows operating system am I running?
All recent versions
Ultimate Doom Builder R4322
20 Jul 2026
MBF21 Game Configuration: fixed a typo that resulted in linedefs with the blocklandmonsters flag to not be pasted correctly after copying
Ultimate Doom Builder R4321
05 Jul 2026
fix: prevent Mono/X11 clipboard crash on paste (#1358)
Ultimate Doom Builder R4320
24 Jun 2026
Add forward-compatible flag to core GL context request (#1360)
Ultimate Doom Builder R4319
24 Jun 2026
Fix visual mode spin with absolute raw mouse input (#1359)
Ultimate Doom Builder R4318
07 Jun 2026
Sectors Mode: fixed a problem where merging sectors would not apply the correct properties when the first selected sector was completely enclosed by other selected sectors