NEC & UPC Code Reference
Searchable national electrical and plumbing code references built into every lesson. Study the rules while you learn the trade.
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Ages 16+ learning system
Study for your trade license — anywhere, anytime
Interactive lessons for electrical, plumbing, HVAC, and more. AR wiring diagrams, NEC/UPC code reference, and practice exams built for working apprentices.
- No ads
- Learning time stays focused and commercial-free.
- Family view
- Parents can understand progress without digging.
- All ages
- Paths scale from early learning to advanced study.
Start with structure
Three clear ways into Koydo.
The footer and navigation can stay simple because deeper choices live on focused category pages. Families choose the door, then Koydo guides the details.
What stays consistent
Designed for learning routines, not clutter.
Koydo can support many subjects and ages without turning the page into a list of loose links. Each surface should explain the next useful step and leave the deeper catalog to dedicated pages.
AR Wiring Diagrams
Point your phone at a panel and see circuit diagrams overlaid in augmented reality. Understand installations before you touch a wire.
Certification Practice Exams
Timed practice tests mirror real journeyman and master exams. Track your pass probability and focus on weak areas.
Built for Working Schedules
Offline mode, 10-minute micro-lessons, and job-site-friendly interface. Study on break, on the bus, or before bed.
Related paths
More ways to keep going.
Ready when your learner is