Why Pet Simulator 99 lags so much
Each pet is an individual animated 3D model. In busy areas like the egg hatching zones or trading spots, you can have 50–100 animated models on screen from your own pets alone, plus other players' pets. Each model has its own animation state and texture. On integrated graphics, this is a lot.
The egg hatching sequence is the worst moment. Multiple particle effects fire simultaneously alongside pet reveal animations. On a budget laptop, this drops FPS from whatever your baseline is down to single digits for 2–3 seconds. That is a GPU bottleneck, not an internet problem.
Reduce the pet rendering load
The most impactful thing you can do in Pet Simulator 99 specifically is to hide other players' pets. Open the in-game settings (the gear icon) and look for an option to hide or limit visible pets. If the option is available in your version, turn it on. This alone removes a large fraction of the rendering load.
In Roblox settings: press Esc, go to Settings, set Graphics Mode to Manual, Graphics Quality to 2. Shadows off. This reduces the rendering cost of each pet model.
Power plan and background apps
Set your power plan to High Performance. Press Win+R, type powercfg.cpl, press Enter. Select High Performance. On a laptop: plug it in.
Pet Simulator 99 runs for long sessions. Background apps accumulate over time. Close your browser and Discord before a long grinding session — they leak memory and compete for CPU resources in ways that become noticeable after 30–40 minutes of continuous play.
Hatch eggs in less-populated areas
If the game lets you choose where to stand while hatching, move away from other players. Each player within render distance adds their pets to what your GPU has to draw. Standing at the edge of an egg area rather than the centre reduces the number of other players in your view.
What to expect
On integrated graphics: expect 20–35 FPS during normal play, dropping to 8–15 FPS during mass hatching events. These settings push normal play to 30–45 FPS. Hatching drops are inherent to the game's design — no client settings eliminate them entirely on integrated graphics.
On a budget dedicated GPU: expect stable 45–60 FPS during normal play. Hatching drops to 25–35 FPS instead of single digits.