I notice you're asking about downloading for free on PC.
Terraria 1.4.5 is not released yet. When it drops, if you own the game on Steam or GOG, it will automatically appear in your library for free. If you don't own it, spend the $5 to buy it legally.
: New world seeds and the ability to mix multiple secret seeds together for unique challenges.
Pirated copies typically cannot access official servers or the tModLoader
For those looking to acquire the game without paying, "free" downloads from third-party sites often carry severe hidden risks: Terraria 1.4.5 - the Launch Date Revealed at Last!
This update introduces over and significant quality-of-life improvements: Terraria 1.4.5 - the Launch Date Revealed at Last!