Looking for a real weight gain simulator game? Our two free titles do exactly that: you feed a cheerful character, the engine models their growth, and you watch them round out bite by bite. No download, no sign-up — just open the page and start the simulation. Both are 100% family-friendly and run in any modern browser.
Click a card to launch the simulator instantly — no install required.
The flagship weight gain simulator: drop burgers, donuts and shakes onto Mochi and watch the 3D model round out in real time. A chill, no-fail feeding sandbox.
▶ Play Feast Feeder 3D — FreeA fast-paced eating simulator: dash the buffet line, grab every dish, and your character bulks up the more you eat. High-score chasing arcade fun.
▶ Play Buffet Rush 3D — FreeA weight gain simulator game is all about a believable transformation. Unlike a one-click clicker, a simulator gives you a sense that you're actually causing the change: you feed the character, the engine tracks how much they've eaten, and their on-screen size grows to match. The best weight gain simulators get three things right — responsive feeding, a clear visual payoff, and a smooth, gradual model of growth so every snack feels like it counts.
Feast Feeder 3D is built around exactly that loop. It's a true 3D weight gain simulator, so when you drop a burger onto Mochi you see the model puff up from a real angle, with squishy physics and a happy little bounce. There's no fail state and no timer — it's a pure sandbox simulation you can sink into for five minutes or fifty. If you'd rather have your simulator with a pulse, Buffet Rush 3D turns the same idea into an arcade dash where speed and combos drive how fast your character grows.
Getting started takes seconds. Open either game page, wait a moment for the 3D scene to load, then start feeding:
Both simulators are free, browser-based, and 100% SFW — pick the calm one (Feast Feeder 3D) or the fast one (Buffet Rush 3D) depending on your mood.
Plenty of weight gain simulators are locked behind a download or an app store. Ours aren't. Because both games are HTML5/3D titles that run instantly in your browser, there's nothing to install, nothing to update, and nothing taking up space on your phone or PC. That also means they're safe to try on a school or work machine where you can't install software — just load the page and play.
If playing a weight gain simulator got you curious about putting on size for real, we have honest, research-backed help. Start with our free Weight Gain Calorie Calculator to find your daily surplus, then read how to gain weight fast the healthy way.
Browse the rest of our free lineup and find the angle that fits you:
A weight gain simulator game lets you control how a character eats and watch a realistic, gradual transformation as they grow rounder. You feed the character food and the simulator models their changing size in real time, turning the simple act of feeding into a satisfying, visible result.
Yes. Feast Feeder 3D and Buffet Rush 3D are both 100% free weight gain simulators that run right in your browser with no download, no install, and no sign-up.
Yes. Feast Feeder 3D is a true 3D weight gain simulator where the character visibly rounds out as you feed it, and Buffet Rush 3D is a fast-paced 3D eating simulator. Both run instantly in modern browsers on desktop and mobile.
Yes. Every weight gain simulator on weightgain.us is 100% SFW. A cute cartoon mascot simply gets pleasantly round from eating, with no nudity, fetish, or adult content of any kind.
The simulators are purely for fun. If you want to gain weight for real, use our free Weight Gain Calorie Calculator to find your daily surplus and follow our healthy weight gain guides.
Both weight gain simulators are free and load instantly in your browser. Pick one and start feeding.