Stop guessing which breaker does what.

The problem

The card inside your panel door is wrong.

Faded pencil with pen over top. The previous owner’s handwriting. Half the breakers just say “lights” and there’s still a waterbed on 23. And you find out how wrong the card is at the worst time: standing in a dark room, flipping breakers, walking back and forth to check what went off.

Circuit Mapper replaces that card with a digital and printed map you build once and update whenever the house changes. It records every room, every outlet, every light, and the exact breaker they run on.

How it works

You don’t need a second person.

The old way takes two people: one at the panel, one shouting back what went dark. Circuit Mapper needs one person and a phone, because the app holds the running record you would otherwise be keeping in your head.

You don’t need to hire anyone for this part. Mapping is turning breakers off and recording what stopped working: no special tools or electrical experience needed.

1. Add what you have: the rooms, then the outlets, lights and appliances in them, then the breakers in your panel.
2. Turn breakers off one at a time, walk the house, and mark each device as off or still on.
3. Keep a searchable map, and print a clean breaker list for the panel door.

How you’ll know a breaker is off

Try it, don’t just look at it. For lights, flip the switch where you’re standing. An outlet has no switch to flip, so bring your charger and plug your phone in as you go. If it starts charging, that outlet is still live. The rest of the method is in the guide.

Even better with a helper

Send them a link (nothing to install, no account, nothing to learn) and the app tells them exactly which breaker to flip while you walk and mark. One person at the panel, one in the rooms, no yelling between floors. The helper’s whole job is flip-this-when-it-says simple, so it can be anyone: a partner, a neighbor, a teenager you’re paying in pizza. There’s a full guide for doing it with two people.

You do not need to remove the panel cover to use Circuit Mapper. Turn off one breaker at a time. Outlet testers and voltage testers are useful checks, not proof that work is safe. If anything looks wrong, stop and call an electrician.

The result

A breaker list you can actually trust.

When you’re done, print a clean breaker list (also called a panel schedule) for the inside of your panel door. Something changes later? Update the map and print it again. No more crossing things out.

Your data

Your map stays yours.

Sign in with your email and we’ll send a 6-digit code. No password to remember. Your map is saved to your account and syncs between your phone and your computer, so you can map at the panel and read it later at your desk. Lose the signal in the basement mid-walk and keep going; it catches up when you’re back.

It stays portable, too: download the whole map as a plain JSON file any time, and you will never have to pay to get your own data back.

Why bother

Worth the afternoon

• Fix a trip in seconds: when something trips, reset the right breaker instead of flipping every switch.
• Pay for the work, not the search: hand an electrician a map instead of paying them to find the circuit first.
• Keep your fridge running: in an emergency, kill the right circuit, not power to the whole house.
• Don’t black out the house to change a switch: know which breaker to kill before you replace a switch, outlet, or fixture, then test before you touch it.
• Know what’s already sharing a circuit: before an EV charger, hot tub, or AC, find out what else is on it. The garage outlet may also be running the freezer.