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 R4307
23 Mar 2026
Update zt-bcc compiler (alpha 5 -> 8) (#1321)
Ultimate Doom Builder R4306
23 Mar 2026
Changed Flatpak Github action to not try to create a release on pull requests
Ultimate Doom Builder R4305
01 Mar 2026
Fixed an issue where DeHackEd things with DoomEdNum -1 were shown in the placeable list of things. Fixes #1304
Ultimate Doom Builder R4304
01 Mar 2026
Fixed an issue where the line activation was not saved correctly in Hexen format. Fixes #1306
Ultimate Doom Builder R4303
28 Feb 2026
Blockmap Explorer Mode: drawing is now handled correctly when resizing the window. Fixes #1313