How to Cut Onions Without Crying: Simple Techniques That Work

Have you ever wanted to slice an onion without ending up in tears? You’re in the right place. This guide explains a simple, reliable method to cut onions without crying, plus a few extra tips to make it easier. No special tools or chef skills required—just a sharp knife and the right technique.

After years of watery eyes in the kitchen, I finally found a foolproof approach. Follow these steps and you’ll stop dreading onion prep.

If you enjoy learning kitchen techniques, try my guide on how to cut an apple.

The secret to avoiding tears has less to do with gimmicks and more to do with how you cut the onion. Keep reading for step-by-step instructions for slicing and dicing, plus a simple breathing trick that acts as a second line of defense.

Alternative Methods and Myths

A quick search turns up many suggested tricks. Some are harmless but ineffective, others inconvenient. Here are a few common ones and why they aren’t ideal:

Wearing goggles: bulky and still allows gas to be inhaled; impractical for everyday cooking.
Using a very sharp knife: helpful for clean cuts, but alone won’t prevent tears unless you cut correctly.
Microwaving the onion: doesn’t reliably stop the irritant gases.
Leaving sliced onion on the board: ineffective and messy.
Freezing the onion for 20 minutes: this can reduce gas release but makes the onion and your hands very cold.

Most of these ideas either don’t work well or are inconvenient. There is a simpler, more dependable method that focuses on how you cut the onion.

How you cut the onion matters

The most important rule: leave the root end attached. Cutting off the root or chopping randomly releases the sulfur compounds that make you cry. Keep the root intact and you’ll dramatically reduce the amount of irritant gas released while you cut.

Also, use a sharp knife—it’s safer and it makes cleaner cuts so fewer cells rupture and release irritants.

How to prepare the onion for cutting

Follow these steps to prepare your onion without releasing too much gas:

1. With the onion upright, slice it in half from top to bottom—but cut through the root, don’t slice the root off. This gives you two halves that still hold together at the base.

2. Trim the opposite end (the top), not the root. Peel away the papery outer skin, leaving the root intact.

With the root still attached, you’re ready to slice or dice according to your recipe.

How to slice an onion without crying

For slices: place the halved onion flat-side down and make vertical cuts from top toward the root, stopping before the root so the layers stay connected. Separate the slices with your fingers.

That’s it—sliced onion without tears. For extra protection, see the breathing tip below.

How to dice an onion without crying

For dice: after halving and peeling, make two or three horizontal cuts toward the root (again, stop short of the root). Then make vertical cuts from top to root across the onion. Finally, slice downward across those cuts to produce diced pieces. The intact root holds the layers together while you work, reducing gas release.

Half a peeled onion that's been sliced twice horizontally

Half a peeled onion that's been sliced twice horizontally with cut lines on it

Half a peeled onion that's been sliced twice horizontally and lots vertically, with cut lines on it

Notice how keeping the root intact makes the process cleaner and lets you see clearly while you work.

A second line of defence

Along with cutting correctly, a simple breathing trick helps a lot: press your tongue gently to the roof of your mouth and breathe through your mouth, not your nose. This forms a small barrier that reduces how much onion gas reaches your nasal passages. Together with the root-on cutting method, it greatly reduces tearing.

That’s all there is to it—cut onions without crying by keeping the root intact, using a sharp knife, and trying the breathing trick. You’ll be chopping with confidence in no time.

How to Cut an Onion Without Crying

Yield:
1

Active Time:
2 minutes

Total Time:
2 minutes

Difficulty:
Easy

Estimated Cost:
Less than £1

Quick instructions for preparing, slicing, and dicing an onion without tears.

Materials

1 x Onion

Tools

Chopping Board
Sharp Knife

Instructions

How to prepare the onion

Cut the onion in half through the root, not through the middle.
Slice off the top end (not the root) and peel away the brown outer skin.

How to slice an onion

With the onion halved and the root intact, make vertical slices toward the root and then separate the slices.

How to dice an onion

Make two or three horizontal cuts toward the root, stopping before the root.
Make vertical slices from one side toward the root.
Finally, slice downward across these cuts toward the root to produce diced onion.