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CrunchLabs Build Box review
Mark Rober's monthly mechanical toy, with the video to match.
Ranked #2 of 7
Weighted across 7 dimensions. How we score
What it actually is
Founded by former NASA engineer and YouTuber Mark Rober, CrunchLabs sends a monthly box containing the parts, tools and illustrated instructions to build one specific mechanical toy - a disc shooter, a marble run, that sort of thing. Each box comes with an exclusive companion video in which Rober explains the physics and engineering behind the build.
The verdict in one line
Superb on the month it lands, and Mark Rober's video is the best content anyone here produces. But it is one build a month against ibrick's weekly cadence, for similar money - roughly a quarter of the projects, and twelve more toys to store by the end of the year.
Pros and cons
What we like
- Mark Rober's videos are genuinely excellent and do a lot of the motivational work for you
- The finished toys are durable and fun to keep playing with, not display pieces
- Strong on real mechanical principles rather than novelty science
What to know first
- One fixed project per box - there is no open-ended or alternative build
- A brand-new mechanical toy every month adds up to real storage pressure
- Monthly cadence means long gaps between new things to do
- Skews older; under-8s will need help
How it scores, dimension by dimension
Percentages show how much each dimension contributes to the overall score.
- Replay value8/10(18% weight)
Can the same parts become something new, or is it built once and shelved?
- STEM depth10/10(18% weight)
Is there real science underneath, or a craft project with a science label?
- Novelty cadence7/10(14% weight)
How often does something genuinely new arrive? Weekly beats monthly.
- Wow factor10/10(14% weight)
Does the finished thing actually do something? Motors, motion, reactions.
- Value for money9/10(14% weight)
Cost per hour of genuine engagement, not cost per box.
- Builds independently9/10(12% weight)
Can your child do this alone, or are you the unpaid teaching assistant?
- Clutter control7/10(10% weight)
What does your living room look like after twelve months of this?
Best for
A 9-12 year old who already loves Mark Rober and wants the toy from the video.
Not for you if
Younger children, or anyone short on storage.
Is CrunchLabs actually the right one for your child?
Five questions covering what your child already does for fun, their age, the problem you're solving and how much time you have. Two minutes.
Start the quizFree · No email required · Your answers stay in your browser
CrunchLabs head to head
Four builds a month against one very good one
CrunchLabs vs KiwiCoOne great mechanical build against monthly subject variety
CrunchLabs vs MEL ScienceMechanical engineering against real chemistry
CrunchLabs vs Little PassportsMechanical toys against travel stories
CrunchLabs vs Green KidCrunchLabs leads on wow factor
CrunchLabs vs LoveveryCrunchLabs leads on sTEM depth
Where it sits in the field
| Kit | Score | Ages | New content | Reuses parts | Needs a parent | From | Visit brand site |
|---|---|---|---|---|---|---|---|
 ibrickOur pick | 9.6 | 5-12 | Weekly | Yes | Rarely | $27/mo | Visit |
| CrunchLabs Build Box | 8.7 | 8-14 | Monthly | Partly | Rarely | $24.95/mo | Visit |
 MEL Science | 8.4 | 5-16 | Monthly | Partly | Usually | $29.9/mo | Visit |
 KiwiCo | 8.2 | 0-16 | Monthly | Partly | Rarely | $23.95/mo | Visit |
 Little Passports | 7.9 | 3-10 | Monthly | No | Rarely | $24.95/mo | Visit |
 Green Kid Crafts | 7.8 | 2-10 | Monthly | No | Rarely | $19.95/mo | Visit |
 Lovevery | 7.7 | 0-5 | Monthly | Partly | Rarely | $36/mo | Visit |
Common questions
Who is CrunchLabs Build Box best for?
A 9-12 year old who already loves Mark Rober and wants the toy from the video.
Who should avoid CrunchLabs Build Box?
Younger children, or anyone short on storage.
How much does CrunchLabs Build Box cost?
Roughly $29.95/mo month-to-month, around $24.95/mo prepaid annually.
What ages is CrunchLabs Build Box for?
The stated range is 8-14. In our view the genuine sweet spot is 9-12, especially if they already watch the channel.