Paintballs are small, compact, ammunition like bullets, so all guns need hoppers. A typical hopper sits on top of the paintball gun and holds about 200 paintballs.

There are a few kinds of paintball hoppers, and the most basic kind just sits on top of the gun and the paintballs hang loosely and drop in to the chamber as each paintball is fired. There are a few electronic versions, and the basic electronic models are powered by one or two nine-volt batteries. These hoppers are slightly larger, although not in profile, because they need to house a small motor. This motor spins a small wheel in the bottom of the hopper that helps feed the paintballs in to the chamber at a faster rate.

In professional tournaments, electronic hoppers are standard because the advanced guns shoot at such a fast rate that a gravity-based hopper will either fail to feed the chamber fast enough to keep up with the trigger causing it to either fire blankly or cause "ball chop," which happens when the paintball falls in to the chamber as the bolt is firing, causing it to explode in the feed.

Typically, if a gun is not electronic and is used to shoot around 2 to 3 balls per second (bps), then a basic model will do. Electronic versions can feed anywhere from 10 bps all the way to in to the mid-twenties. Knowing how fast a marker shoots and its desired use is the first step in determining the proper paintball hopper to purchase.

Other priorities in hopper choice will include quality, fit and profile. When looking at quality, the lid is going to be the most important piece to look at. A good lid is important, because it needs to release and enclose durably. If a player needs to reload in the middle of the game, he can ill afford to spend his time springing it open, and it would be just as bad to dump ammunition because of a poor quality locking lid. The fit is important for similar reasons, because a loose connection to the marker will prevent the player from shooting from different angles for fear of an ammo dump. The last thing to look at is the profile of the hopper. Lots of new hopper design has been focused on making a smaller target for other players because it has been such a large unavoidable one in the past.

The most important thing to remember is that a good hopper is key to concentrating on the game.