Do You Need to Preheat an Air Fryer?

No, you do not have to, but it usually helps. Makers split on it: Ninja says always preheat for three minutes, COSORI says food will not cook thoroughly without it, and Philips says it is not necessary. If you skip it, add one to five minutes to the cook.

Here is what each maker says about whether you need to preheat an air fryer, how long it takes, how to tell it is ready, and which foods can go in cold.

What Air Fryer Makers Say About Preheating

The advice runs from “always” to “not necessary,” and it depends on the model. Each row comes from the maker’s own manual or support page.

Nobody says preheating does harm. The makers differ on whether skipping it is acceptable, and the two that recommend it most firmly, Ninja and COSORI, build their instructions and recipes around a hot basket.

How Long to Preheat an Air Fryer

Three to five minutes covers every maker above. Ninja says three minutes, Chefman five, and Philips allows one to five minutes of extra cook time instead. COSORI is the only one to publish a table, and it scales with temperature:

The table is from the COSORI Pro LE 5.0 Quart manual, so treat it as a guide for other models rather than a rule. If your manual gives a different time, follow it.

How to Preheat an Air Fryer Without a Preheat Button

1. Empty the basket. Preheat with nothing in it, and keep paper and foil out until the food goes in.
2. Set the temperature you will cook at. COSORI’s button defaults to 400°F, so change it if the recipe calls for less.
3. Run it for three to five minutes. Ninja suggests setting the built-in timer to count down three minutes.
4. Add the food promptly. Chefman warns that the inside is hot after preheating, so use care when loading.
5. Cook as normal. Start your timer once the food is in.

How to Tell When an Air Fryer Is Preheated

It depends on the model. COSORI beeps three times and shows the set temperature. Instant Vortex models show Add Food, and the Vortex Dual also lights three preheat indicators. Ninja’s AF100 guide gives no signal, which is why it suggests a three-minute countdown.

If your fryer has neither a beep nor a prompt, use the timer.

Some air fryers preheat on their own and some do not, so check the display before assuming. Pressing start on an Instant Vortex preheats first, while Ninja’s AF100 and Chefman’s TurboFry Touch leave preheating to you.

What Happens If You Skip Preheating

The makers claim two things. Chefman says preheating cooks food faster and promotes crisp results, and COSORI says food will not cook thoroughly without it. Philips and Chefman both say to add time if you start cold: one to five minutes from Philips, a few minutes from Chefman.

Independent testing is thin. The only side-by-side comparison available is a single home test by Fabulessly Frugal, who cooked frozen tater tots and chicken breasts cold and preheated. The tots came out crisp either way, and the chicken cooked in times two to three minutes apart. One run on one machine is not proof, but it fits the makers’ own advice that a cold start mostly costs a few minutes.

If your food is coming out pale or damp rather than crisp, preheating is one of several causes, and why air fryer food is not crispy covers the rest.

Which Foods Benefit From Preheating

The makers do not publish food lists, so this is a rule of thumb from how the machine works rather than a tested ranking. Preheat when the cook is short or the surface matters: steaks and burgers, thin or breaded items, and anything you want browned from the first minute. The recipes in Ninja’s AF100 guide for fries, chicken and cod each begin with a three-minute preheat.

A cold start costs little on long cooks. Three minutes of warm-up is about five percent of a one-hour roast, and the time is easy to make up. Reheating leftovers is another case: Instant Pot’s Reheat program is designed with no preheating time at all.

Common Preheating Mistakes

• Leaving paper or foil in the basket. Airflow is strongest during preheat and can lift an empty sheet into the element. Parchment paper in an air fryer and aluminium foil in an air fryer both explain the rule.
• Preheating to the wrong temperature. A preheat button may default to 400°F, which is too hot for a 350°F recipe.
• Assuming it preheats itself. Instant Vortex models do; Ninja’s AF100 and Chefman’s TurboFry Touch do not.
• Letting the basket stand open. Add food soon after the machine signals ready, so the heat you waited for is not wasted.

Oven-Style Air Fryers

Oven-style models behave more like an oven, and the Instant Pot oven manual says to wait for Add Food. If you are weighing the two designs, air fryer vs convection oven explains the differences.

How This Page Was Put Together

This page is based on maker manuals and support pages, not on testing; I do not own or test air fryers. The sources are the Ninja AF100 owner’s guide, the COSORI Pro LE manual, the Philips US FAQ, the Chefman TurboFry Touch manual, and the Instant Pot Vortex Dual and Vortex Plus 10 Quart manuals.

What I could not establish: COSORI’s online preheating article, which sits behind a login, any controlled test from an independent lab, and whether preheating changes energy use in a meaningful way. Nobody publishes those figures.

The Verdict

Preheat for three to five minutes when you want a crisp, browned surface or your maker says to, and skip it for long cooks and reheats, adding a few minutes. Check your manual first, because the models above disagree. The complete air fryer guide covers everyday use, and the best air fryers guide compares models that make preheating easy.

Frequently Asked Questions

Do you have to preheat an air fryer?

No, but most makers recommend it. Ninja and COSORI say to preheat, while Philips says it is not necessary and Chefman calls it optional. If you skip it, add one to five minutes to the cook so the basket can heat up with the food inside.

How long should you preheat an air fryer?

Three to five minutes. Ninja recommends three, Chefman five, and COSORI scales from two minutes at low temperatures to four minutes at 400°F and above. Follow your own manual if it gives a time, because the makers above differ and the time depends on the temperature.

Can you preheat an air fryer without a preheat button?

Yes. Empty the basket, set the temperature you will cook at, and run it for three to five minutes, using the timer as a countdown if there is no signal. Then add the food promptly and start the cook as normal.

Does an air fryer preheat itself?

Some do. Instant Vortex models start preheating when you press start and show Add Food when ready. Ninja’s AF100 and Chefman’s TurboFry Touch leave it to you, so check the display or your manual before assuming the machine has done it, and set a timer if in doubt.

How do you know when an air fryer is preheated?

Look for the signal. COSORI beeps three times and shows the set temperature, and Instant Vortex models display Add Food. Ninja’s AF100 guide has no signal and suggests a three-minute countdown, so use the timer if yours is silent and wait the full time before loading.

How much longer does food take without preheating?

Philips says to add one to five minutes, and Chefman says a few minutes. In the one published home test, chicken breasts differed by two to three minutes. Check early the first time, because models heat at different speeds and food varies.

Is it safe to preheat an empty air fryer?

Yes. COSORI’s manual preheats with the basket empty, and Ninja preheats before adding ingredients. Keep parchment paper and foil out until the food goes in, because airflow can lift a loose sheet into the heating element during preheating, which is the main risk.