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 R4327
13 Sep 2026
Fixed URL to the ZDoom wiki in the DSDADoom UDMF, Helion UDMF, and ZDoom based UDMF game configurations.
Ultimate Doom Builder R4326
06 Sep 2026
Fixed a bug where the lightfog sidedef UDMF property was disabled when changing a sidedef's brightness.
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