18 month onesies boy
Skip itA deep review moat (24,899 avg reviews) — this niche doesn't clear our bar today.
Competition
Incredible12%top-5 click share — an open shelf
Avg price
Great$19.82avg listing price — sweet spot $15–$100
Returns
Good2.1%return rate — above 5% kills the launch gate
Price range
Good$6.55–$32.16cheapest to priciest tracked listing — scored on the share inside $15–$100
Conversion
Okay2.3%search→purchase rate — share of searches ending in a sale
Brand share
Okay89%top-5 brand share — brands hold most of the demand
Growth
Bad-13.2%90-day search growth — must beat 0% to launch
Quality gap
Bad4.7★avg incumbent rating — lower means beatable quality
Market size
Bad$65K$65K/yr · 142K searches
Review moat
Bad24,898.72avg incumbent reviews — the moat a new listing must climb
According to Flapen's Amazon United States niche tracking, 18 month onesies boy is a $65K/yr Amazon United States market (142K searches/yr). The top 5 brands hold 89% of demand. Demand peaks in Dec. Verdict: Skip it — 43/100.
Data updated Jul 8, 2026 · scored weekly · How we score niches
18 month onesies boy market data
- Units sold / yr
- 4K–5K
- avg 0–100/product
- Revenue / yr
- $79K–$99K
- units × avg price
- Conversion rate
- 2.3%
- Avg BSR
- #82
- Page quality
- 0%
- Prime
- 100%
- Sponsored
- 87%
- Out of stock
- 5.3%
- Avg brand age
- 38 months
- Avg seller age
- 152 days
Competition & brand share
Clicks spread well past the top 5 (12% combined) — an open shelf where new products get seen.Brands
19 flat
Sellers
26
Top-5 brand share
89%
Top 20: 100%
Top-5 click share
12%
Top 20: 32%
Open market
9%
- Gerber33%
- Simple Joys by Carter's30%
- Amazon Essentials12%
- Onesies Brand12%
- Hudson Baby2%
- little planet by carter's2%
- Open — no brand owns it (13 brands, 9%)
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -13.2% search growth over the last 90 days.Peak months: Dec · busiest ÷ quietest = 1.9×
Top 18 month onesies boy search terms
- 12 month boy onesies20K/yr
- 12 month girl onesies18K/yr
- onesie 18 months girls11K/yr
- onesies 18 months boy11K/yr
- 18 month boy onesies9K/yr
- onesie 18 months boy8K/yr
- carters onesies 18 months7K/yr
- 18 month girl onesies8K/yr
- 12-18 month girl onesies8K/yr
- onesies 9-12 months boy7K/yr
Top 18 month onesies boy products on Amazon
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
All 24 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Gerber Baby 8-Pack Short Sleeve Onesies Bodysuits Solid White 18 Months
Gerber$16.624.8★56,105 rev
Gerber Baby 8-Pack Short Sleeve Onesies Bodysuits Solid White 12 Months
Gerber$16.814.8★56,105 rev
Simple Joys by Carters Baby Girls Short-Sleeve Bodysuit Pack of 6 Multicolor/Dinosaur/Floral/Forest Animals/Fruit/Hearts 18 Months
Simple Joys by Carter's$18.074.8★69,956 rev
Gerber Baby Girls 8-pack Short Sleeve Onesies Bodysuits Shirt Golden Floral 12 Months US
Gerber$24.424.8★31,228 rev
Amazon Essentials Baby Girls Short Sleeve Bodysuit Dress Everyday Dresses Pack of 3 Pink/Apples 18 Months
Amazon Essentials$22.734.8★2,442 rev
Newest
by launch dateSimple Joys by Carters Baby Girls Short-Sleeve Bodysuit Pack of 6 Multicolor/Dinosaur/Floral/Forest Animals/Fruit/Hearts 18 Months
Simple Joys by Carter's$18.0769,956 rev
Simple Joys by Carters Baby Girls 6-Pack Short-Sleeve Bodysuit Multicolor/Dinosaur/Floral/Forest Animals/Fruit/Hearts 12 Months
Simple Joys by Carter's$14.9469,956 rev
Simple Joys by Carters Unisex Babies Short-Sleeve Bodysuit Pack of 6 Animal/Stripe/Geo Tile 18 Months
Simple Joys by Carter's$19.1810,631 rev
Simple Joys by Carters Baby Boys Short-Sleeve Bodysuit Pack of 6 Multicolor/Alligator/Forest Animals/Stripe 18 Months
Simple Joys by Carter's$19.8066,953 rev
Simple Joys by Carters Unisex Babies Short-Sleeve Bodysuit Pack of 8 Navy Heather/White/Oatmeal 12 Months
Simple Joys by Carter's$16.3922,295 rev
Trending
90-day click momentum
Amazon Essentials Unisex Toddlers Baby Unisex 6-Pack Sleeveless Bodysuits Blue/Dogs 18 Months
Amazon Essentials$15.384.8★
Simple Joys by Carters Baby Girls Short-Sleeve Bodysuit Pack of 6 Multicolor/Birds/Fruit/Lemon/Turtle 18 Months
Simple Joys by Carter's$18.704.8★
Amazon Essentials Baby Girls Short Sleeve Bodysuit Dress Everyday Dresses Pack of 3 Pink/Apples 18 Months
Amazon Essentials$22.734.8★
Simple Joys by Carters Baby Boys 6-Pack Short-Sleeve Bodysuits
Simple Joys by Carter's$18.744.8★
Simple Joys by Carters Baby Girls 6-Pack Short-Sleeve Bodysuit Multicolor/Dinosaur/Floral/Forest Animals/Fruit/Hearts 12 Months
Simple Joys by Carter's$14.944.8★
What buyers say about 18 month onesies boy
What buyers praise and complain about, mined from review topics.What buyers love
“Fit right on my baby”
“Excellent product line”
“The material is soft”
“Nice and comfortable”
“comfortable material”
“Colors are beautiful”
“Good buy for the money”
“As advertised”
“Overall material is warm”
“Soft and durable”
What buyers complain about
“Does not fit well”
“Material really bad and very tight”
“Low quality”
“not 2-way zipper”
“not meant for chunky babies”
“not durable”
“The colors are very pale”
“Misleading and itchy”
“Shrinks the more u wash them”
“if you can call it that- it wasnt stretchy”
Top return reasons
Common questions
- Is 18 month onesies boy profitable to sell on Amazon United States?
- The niche generates $65K/yr across 181 tracked products. 46 of 68 products launched in the last 360 days are still selling. 90-day search growth is -13.2%. Flapen's verdict: Skip it (43/100).
- How competitive is the 18 month onesies boy niche?
- 19 brands and 26 sellers compete. The top 5 products take 12% of clicks and top 5 brands hold 89% of demand.
- What do buyers complain about in 18 month onesies boy?
- Top complaints mined from reviews: Size-Overall, Material Quality, Quality-Overall. The return rate is 2.1%.
- When does demand for 18 month onesies boy peak?
- Demand peaks in Dec; the busiest month runs 1.9× the quietest.
- What does it cost to enter the 18 month onesies boy niche?
- Listings span $6.55–$32.16; the average listing price is $19.82 (sweet spot $15–$100). The average incumbent carries 24,899 reviews — the moat a new listing must climb.