Source SDK Release Notes

Note:The latest release note on Steam News page is no longer updated. This page is currently up to date as of Feb 2025.

Note:If you see this page when you first open the "Source SDK" (AppID 211) launcher, please note that the old Source SDK launcher are no longer updated, and does not support Source 2013 games.

To launch the SDK applications (Hammer, HLMV, etc...) manually, see SDK Installation - SteamPipe_migration section.

Source SDK 2013 update (2/18/2025)

An update to Source SDK 2013 has been released. The major changes include:

Singleplayer (Source 2013 Singleplayer)

• Added a borderless window option to video settings
• Added bicubic lightmaps (from Half-Life 2: 20th Anniversary Update)
• Added radial fog (from Half-Life 2: 20th Anniversary Update)

Todo: More?

Multiplayer (Team Fortress 2 branch)

Note:Info copy-pasted from Counter-Strike: Source Feb 18, 2025 update notes, and edited to only mention fixes that applies to all updated games ( to , like , ), and SDK 2013 MP. Game-specific fixes are not included here.

• Added 64-bit Support. 64-bit binaries will automatically be launched on systems with a 64-bit OS.
• Added a borderless window option to video settings
• Added bicubic lightmaps (from Half-Life 2: 20th Anniversary Update)
• Added radial fog (from Half-Life 2: 20th Anniversary Update)
• Added support for Steam Networking
• Added UI scaling for high-resolution screens
• All remaining Valve games running on Source 2013 Multiplayer (, , and SDK) have been upgraded to Team Fortress 2 branch.
• Made the default server name for listen servers include the player's name
• Made the game launch in native resolution by default instead of 640x480
• Client-side prediction fixes (these fix 'jank'/rollback in certain situations)
  • Fixed a prediction bug where if the player was moved on the client, their input-based movement for that tick was not taken into account in non-player actions
  • Improved prediction for walking on props and other entities
  • Made certain client-side entities only trigger local prediction errors
    • e.g. If the viewmodel experiences a prediction error, the player will not experience a prediction error
  • Fixed prediction of viewmodel sway
  • Fixed a prediction error regarding weapon idle animations
• Fixed certain breakable props not gibbing correctly
• Fixed an issue where certain variables like position would not be updated correctly to match the server in certain situations
• Fixed the player's base velocity (eg. conveyors, moving items etc.) getting subtly out of sync from client/server

Updated source code

• Source 2013 Singleplayer (2025 version): Source SDK 2013 GitHub repo.
  
• TF2 branch (newer Source 2013 MP): Source SDK 2013 GitHub repo.

Previous releases

• See the Source SDK release notes archive for information on previous releases.