Onion vs Green Onion / Negi
What's the difference between onion and green onion (negi)?
Both belong to the Allium family, but onions are bulbs while negi (Japanese green onions) are eaten for their leaf sheaths. They play very different roles in cooking.
Nutrition (per 100g)
| Nutrient | Onion | Green Onion / Negi |
|---|---|---|
| Calories | 33kcal◎ | 35kcal |
| Protein | 1g | 1.4g◎ |
| Fiber | 1.5g | 2.5g◎ |
| Vitamin C | 7mg | 14mg◎ |
| Iron | 0.3mg | 0.3mg |
| Calcium | 17mg | 36mg◎ |
| Potassium | 150mg | 200mg◎ |
| Beta-carotene | 1μg | 83μg◎ |
| Folate | 15μg | 72μg◎ |
Source: Standard Tables of Food Composition in Japan (8th ed.) 2020
Price Comparison
Onion
Annual average (2026)
Green Onion / Negi
Annual average (2026)
Peak Season
| J | F | M | A | M | J | J | A | S | O | N | D | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Onion | ○ | ○ | △ | Peak | Peak | ○ | ○ | ○ | ○ | ○ | ○ | ○ |
| Green Onion / Negi | Peak | Peak | ○ | — | — | — | △ | △ | — | △ | Peak | Peak |
Storage & Flavor
Onion
Flavor
A distinctive flavor combining pungency and sweetness. Cooking intensifies the sweetness. New onions have milder heat and are suitable for eating raw
Shelf Life
1-2 months at room temperature (cured onions), new onions 1-2 weeks refrigerated
How to Select
Choose onions with dry, papery outer skins. The top should be firm and the onion should feel heavy. For new onions, look for thin, white skins
Green Onion / Negi
Flavor
The white part becomes creamy and sweet when cooked. The green part has a stronger pungency and aroma, making it ideal as a condiment. Cold weather develops sweetness; negi that has been exposed to frost in winter is exceptionally sweet
Shelf Life
Refrigerated: 1-2 weeks; frozen (sliced): 1 month
How to Select
Choose negi with a clear boundary between white and green parts, and a long, thick white section. The leaves should stand upright and the whole stalk should be firm. Look for moist, fresh-looking cut ends
Verdict
Onions are the universal cooking base across all cuisines, with unbeatable cost-performance and 2+ months of room-temp storage. Negi is indispensable in Japanese cuisine — from garnish to star ingredient — with different nutrition in its white and green parts.
FAQ
Can onion and negi substitute for each other?
In cooked dishes, negi can often replace onion. However, replacing negi as a garnish with onion is difficult since the flavors are quite different.
Which is better raw?
Onion is sliced for salads and vinegar dishes. Negi is chopped as a garnish. Both become milder when soaked briefly in water.
Which stores longer?
Onions win — 2+ months at room temperature. Negi keeps 1–2 weeks refrigerated, but can be chopped and frozen for a month.