The official HD texture pack on Steam is DLC locked to your Steam account. You cannot download it legally without Steam.
However, you can:
GOG users have uploaded manual installers. Look for pinned posts by user “BurningMoon” or “HKPD_Officer”.
ModDB hosts the “Sleeping Dogs – Ultimate Texture Pack” (community repack). Search for “SleepING HD Revival” — it merges the official HD pack with fan-made fixes for normal maps.
Popular Sources for Texture Packs:
Considerations and Precautions
Conclusion
High-resolution texture packs can significantly enhance the gaming experience for Sleeping Dogs players, offering improved visuals and a more immersive gameplay experience. While non-Steam users might face a few extra steps in finding and installing these packs, the benefits can be well worth the effort. By carefully selecting and installing high-resolution texture packs, players can breathe new life into this already engaging game, making it a more enjoyable and visually stunning experience. The official HD texture pack on Steam is
Since you are using a non-Steam version, you likely have the original release.
This process works for all non-Steam versions—cracked, GOG, retail disc, or repack.
Because you are not using Steam, the automated download via the Steam Workshop or Store page is unavailable. You have two options: Considerations and Precautions
Option A: Re-download a Pre-Packed Version (Recommended) Most "non-Steam" versions available today are "Complete Editions" or "Repacks" (e.g., from sites like SteamRip or specific repack groups).
Option B: Manual Download (The "UPD" Method) If you already have the base game installed without the pack, you need to find the specific texture pack files.