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 R4301
26 Feb 2026
Fixed installer to include the Blockmap Explorer Mode DLL
Ultimate Doom Builder R4300
26 Feb 2026
Some fixes for building Blockmap Explorer Mode on Linux
Ultimate Doom Builder R4299
26 Feb 2026
Added Blockmap Explorer Mode
Ultimate Doom Builder R4298
18 Feb 2026
Add possibility to multiselect thing types in Find/Replace window. (#1288)
Ultimate Doom Builder R4297
18 Feb 2026
More fixes to Flatpak build action