How long does chopped onion last in the fridge?
Chopped onion lasts 7 to 10 days in the fridge in a sealed airtight container at 40°F or below, per USDA data. Includes the full storage table, spoilage signs, and freezing tips.
Chopped onion keeps for 7 to 10 days in the refrigerator when stored in a sealed, airtight container at 40°F or below, according to USDA data cited by the National Onion Association. Without a tight seal, plan on 3 to 5 days instead, and if you bought it pre-cut, follow the package date.
How long does chopped onion last in the fridge?
The storage window depends on the cut, the container, and the temperature. A whole, unpeeled onion barely needs the fridge at all, but once you slice into it, the clock starts running.
| Onion form | Pantry or counter | Refrigerator, 40°F or below | Freezer, 0°F |
|---|---|---|---|
| Whole onion, uncut | About 1 month, cool and dark | About 2 months | 10 to 12 months |
| Chopped, sliced, or diced onion, sealed airtight | Not recommended | 7 to 10 days | Best quality 3 to 6 months, safe indefinitely if kept frozen |
| Chopped onion, loosely wrapped or unsealed | Not recommended | 3 to 5 days | Not recommended |
| Chopped green onions or scallions | Not recommended | 1 to 2 weeks | 10 to 12 months |
| Any cut onion left at room temperature | Use within 2 hours, or 1 hour above 90°F | Refrigerate right away or discard | n/a |
For a broader list of storage windows by food type, see our guide to how long food lasts.
How to tell if it has gone bad
Trust your senses first. Chopped onion that has turned should show one or more of these signs:
- A sour, sulfurous, or ammonia-like smell that is stronger and sharper than fresh onion
- A slimy, wet, or mushy texture, especially at the cut edges
- Visible mold, or a fuzzy or discolored patch anywhere in the container
- A pink, gray, or orange tinge on the onion or in any liquid that has collected in the container
Some spoilage bacteria do not change the smell, texture, or color of cut produce at all, which is why the day count in the table above matters even when the onion looks and smells normal. After 7 to 10 days, go by the calendar rather than your nose.
How to store it so it lasts
- Use a truly airtight container, such as a glass jar or a rigid plastic tub with a snap-on lid, rather than a loosely folded bag or a plate with plastic wrap draped over it.
- Keep your refrigerator at 40°F or below. A fridge thermometer is the only reliable way to know, since the dial on the door is often off by several degrees.
- Chop only what you need for the next several days. Onion loses moisture and pungency the longer it sits cut, even before it becomes unsafe.
- Label the container with the date you cut it, since it is easy to lose track after a few days in a crowded fridge.
- If you bought pre-chopped onion from the store, use the manufacturer's use-by date instead of the general guidance above, since processing conditions vary.
If keeping track of dates is the part that trips you up, Well Stockd's food expiration tracker logs the day you chopped something and sends a reminder before the window closes.
Can you freeze it?
Yes, and it is one of the easier vegetables to freeze. Onions do not need to be blanched first, so you can peel, chop, and pack them straight into a freezer bag or airtight container with the air pressed out. For best quality, use frozen chopped onion within 3 to 6 months, though it stays safe to eat indefinitely as long as your freezer holds a steady 0°F or below. Expect a softer, more watery texture after thawing, which is fine for soups, sauces, and sautes but not for anything you planned to eat raw. There is no need to thaw first; add frozen onion straight to a hot pan.
When in doubt
USDA guidance is simple: when you are unsure, throw it out. Cut onion that has passed the 7 to 10 day window, or that sat out at room temperature for more than 2 hours (1 hour if your kitchen is above 90°F), is not worth the risk of foodborne illness just to avoid waste. Onions are more forgiving than many other fridge staples. If you are also wondering about how long cooked rice lasts in the fridge or how long raw chicken lasts in the fridge, both have tighter windows because they carry a higher food-safety risk.
Frequently asked questions
Do you have to refrigerate chopped onion right away? Yes. Cut onion is perishable and should go into the fridge within 2 hours of chopping, or within 1 hour if your kitchen is above 90°F. Past that window, USDA guidance says to throw it out rather than risk it, even if it looks fine.
Can you use chopped onion after 10 days if it still looks and smells okay? No. The 7 to 10 day window is a food-safety limit rather than a freshness suggestion, because some bacteria that grow on cut produce do not change how it looks or smells. Once the count runs out, USDA guidance says to toss it rather than judge by appearance alone.
Does chopped onion need to be blanched before freezing? No. Onions are one of the few vegetables that do not require blanching before freezing. Peel, chop, and freeze them directly in a sealed bag or container, then cook them straight from frozen.
Updated July 2026.
Sources: USDA FoodKeeper App, FoodSafety.gov; National Onion Association FAQ, citing USDA data; USDA Food Safety and Inspection Service, How Temperatures Affect Food.