One of the carpet cleaners in Consumer Reports tests.

Designed to remove deeply embedded dirt and debris, carpet cleaners are a smart addition to your cleaning arsenal, especially if you have a busy household and a home with lots of carpet. They can handle stains and ground-in dirt in a way even the best vacuums can’t.

“Carpet cleaners are nothing like a standard upright vacuum,” says Larry Ciufo, who oversees Consumer Reports’ carpet cleaner tests. In fact, “the instructions for these machines tell you to vacuum your floor first using a conventional vacuum cleaner, and then use the carpet cleaner to clean up embedded dirt.”

The carpet cleaners in our tests cost about $100 to nearly $500, but you don’t have to spend a bundle to get spotless carpets.

How We Test Carpet Cleaners

It takes three days to put one carpet cleaner through our battery of cleaning-performance tests. Our engineers soil large swatches of off-white nylon carpet with red Georgia clay. They run a carpet cleaner over the carpet for four wet and four dry cycles to simulate a consumer cleaning a particularly dirty spot on a well-trafficked carpet. Then they repeat the test on two more swatches.

Over the course of the test, our experts use a colorimeter, a device that measures the absorption of light wavelengths, to take 60 readings of each carpet per test: 20 in its “virgin” state, 20 after it has been soiled, and 20 after it has been cleaned. Sixty readings on three samples makes a total of 180 readings per machine.

How to Choose a Carpet Cleaner

Considering one of these powerful cleaning machines? Here are five things to keep in mind as you shop:

1. Carpet cleaners are heavy when empty—and even heavier full. Adding a cleaning solution to the models in our ratings can add 6 to 15 pounds. We list the weight of each carpet cleaner when empty and when full on the model page for each one.

The largest cleaner in our tests, the Bissell Big Green Machine Professional 86T3, $470, weighs 58 pounds when full and may be difficult for one person to maneuver. The lightest model we tested, the Bissell PowerLifter PowerBrush 1622, $100, weighs 16 pounds empty and 22 when the tank is full.

More on Floor Care

2. There’s no need to spend top dollar on cleaning solution. Many manufacturers recommend that you use their brand’s cleaning solution with their carpet cleaner.

We ran each model through our cleaning tests with water alone, then with water and detergent. Each machine performs better with cleaning solution than without it, but the ranking order remained the same in each case, meaning that the machine's cleaning performance was still relative to its design.

Depending on the type of stains you have, you might need to shell out more money for a stain-specific detergent. But for routine carpet cleaning, that's not necessary.

3. Check the accessories and length of the hose. Some carpet cleaners have only one tank for water and the cleaning solution. But it’s more convenient to have one tank for water and one for the cleaning solution. Also look for a carrying handle to help you move the machine around.

Our testers noted that hose length varies widely. Some models have a 61-inch hose; others have a 120-inch hose. Look for a model with a longer hose if you need to clean in tough-to-reach areas. “If your stairs have carpeting, you’ll want to have a longer hose to reach up the steps,” says Ciufo. “Remember, these machines are heavy. You certainly don’t want your machine falling down the stairs after you tug the hose too far.”

4. Carpet cleaners are loud. An average vacuum cleaner can produce up to 70 decibels of noise. A carpet cleaner is much, much louder—in our tests, the average noise level was 80 decibels. (In decibels, a reading of 80 is twice as loud as 70.) This is the level at which we recommend hearing protection, especially if you’re using the machine for a prolonged period. So grab noise-canceling headphones or earplugs that guarantee protection for up to 85 decibels. (Check out these tips for preventing hearing loss.)

5. Carpet cleaners take some time. A vacuum can come out of the closet ready to go. But a carpet cleaner? Not so much. First you have to move furniture out of the area you plan to clean, then you should vacuum the carpet. Next, fill the machine with cleaning solution and water.

When using a carpet cleaner, you push it back and forth just like a vacuum while also squeezing a trigger to release the cleaning solution. Push the carpet cleaner out to arm’s length, then pull it back while continuing to squeeze the trigger.

To suction the cleaning solution from the rug, make dry passes with the carpet cleaner. If the carpet is still dirty, repeat wet and dry passes until the cleaning solution you removed from the carpet runs clear. Once you’re satisfied, let the carpet dry completely before you walk on it or replace the furniture.

You’re not done yet. After admiring your work, you have to unplug the machine, clean out the tank, and remove any debris from the brushes following the instructions in your owner’s manual.

For more, see our carpet cleaner buying guide.