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 R4325
22 Aug 2026
Added Helion UDMF configuration (#1364)
Ultimate Doom Builder R4324
22 Aug 2026
Updated ACC for Zandronum 3.3 (#1373)
Ultimate Doom Builder R4323
22 Jul 2026
Fixed a crash in the thing browser control when a pre-set selection was not changed. Fixes #1367
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)