The R3 Score is a weighted average of 10 criteria specific to lunch boxs. Safety and its primary function carry more weight than nice-to-haves.
Score breakdown
The bottom line
Here's what we'd tell a friend
What you should know first
The gasket seal is genuinely leakproof — we tested it, and yogurt stays put. But there's no insulation (4.5/10), so that yogurt will be room temperature by lunch. Pack an ice pack if cold matters.
Go for it if...
You need truly leakproof compartments — 9.5/10, the gasket seal actually works
Your kid carries their lunchbox in a backpack and you can't risk spills on homework
Tops the category on leak proof performance (9.5/10) — worth checking insulation performance before buying.
Leak Proof Performance
Ease Of Use
8.5Safety
7.9Efficacy
8.6Usability
7.5Value
Key insights
Renee's Take
We dug through 3 reviews — the one-piece silicone gasket design earns a 9.5/10 on leak-proof performance — the seal closes all 5 compartments simultaneously, no individual lids to forget — but BPA-free plastic doesn't hold temperature (4.5/10), making this the right pick for families who've had nightmare lunchbox spills and want guaranteed dry bags over hot food
How does Yumbox Original Leakproof Bento Box perform on leak proof performance?▼
This product scores 9.5/10 on leak proof performance, which is one of its strongest areas.
Is the Yumbox Original Leakproof Bento Box worth $33.99?▼
At $33.99 with a score of 8.1/10, this is a solid value for the performance you get.
What about insulation performance?▼
This product scores 4.5/10 on insulation performance. This is an area to consider carefully.
Is the Yumbox Original Leakproof Bento Box right for my family?▼
Based on our analysis of 10 factors, this lunch box scores 8.1/10 overall. Check the "Go for it if..." and "Maybe skip if..." sections above for personalized guidance.
Care & Tips
Keep your Yumbox Original Leakproof Bento Box performing at its best
Wash all compartments with warm soapy water after every use — food residue left overnight causes stains and odors that become permanent.
After each use~3 min
Remove and wash the silicone gasket or seal around the lid separately — this is where food particles and mold accumulate most.
After each use
For stubborn stains or odors, soak in warm water with baking soda for 30 minutes before scrubbing.
As needed~30 min
Store with the lid slightly ajar when empty so air can circulate and prevent musty odors from building up.
Avoid using abrasive scrubbers on stainless steel compartments — they scratch the surface and create microscopic grooves where bacteria can hide.
Check latch mechanisms and seals regularly for wear. A degraded seal means leaks in your bag — replace the gasket annually or when it shows cracking.
Monthly check
Pro Tip
Check latch mechanisms and seals regularly for wear. A degraded seal means leaks in your bag — replace the gasket annually or when it shows cracking.
Where to buy
Verified retailers with current pricing
Yumbox Original Leakproof Bento Box
Yumbox
$33.99
$50.98Save $17 (33% off)
Prime eligible
In stock
Free shipping with Prime
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Last reviewed: March 6, 2026 · Based on 3 verified purchase reviews
Nothing ruins a day like a soaked backpack. I test every lunchbox upside down before it goes to school.
Nothing ruins a day like a soaked backpack. I test every lunchbox upside down before it goes to school.
Compartment design determines how fast I can pack and whether my kid actually eats everything I pack.
Compartment design determines how fast I can pack and whether my kid actually eats everything I pack.
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Food safety is the real question — it's not just about taste, it's about cold items staying at safe temps through lunch.
Food safety is the real question — it's not just about taste, it's about cold items staying at safe temps through lunch.
My take
My take
●I cannot deal with mold traps in lunchboxes — wide openings and dishwasher-safe construction are non-negotiable for me.
●I cannot deal with mold traps in lunchboxes — wide openings and dishwasher-safe construction are non-negotiable for me.
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If my kid can't open their lunchbox, they won't eat — child-independent latches matter more than adults realize.
If my kid can't open their lunchbox, they won't eat — child-independent latches matter more than adults realize.
A $40 stainless lunchbox that lasts 5 years is better value than a $10 plastic one you replace every year.
A $40 stainless lunchbox that lasts 5 years is better value than a $10 plastic one you replace every year.
●Lunchboxes take abuse — drops, slams, and daily washing. The hinges and seals are what fail first.
●Lunchboxes take abuse — drops, slams, and daily washing. The hinges and seals are what fail first.
Dimensions matter — a lunchbox that doesn't fit the school bag isn't a real option.
Dimensions matter — a lunchbox that doesn't fit the school bag isn't a real option.
Replacement parts availability is how I know a brand stands behind their product long-term.
Replacement parts availability is how I know a brand stands behind their product long-term.
