Comparison

GFCI vs AFCI vs Dual-Function Protection

A GFCI protects against shock, an AFCI against arcing fires, and dual-function devices do both. One does not replace the other.

Electrical & Power · Last reviewed October 17, 2026

Short answer: a GFCI addresses the risk of electric shock, an AFCI addresses the risk of fire from arcing in wiring and cords, and a dual-function device does both. Install the protection that the code requires for each location. Neither device substitutes for the other.

	GFCI	AFCI	Dual-function (AFCI and GFCI)
What it detects	Current leaking to ground, shown by an imbalance between the hot and the neutral	The signature of an arcing fault in the wiring or in a cord	Both
Hazard addressed	Electric shock and electrocution	Fire from arcing	Shock and fire
Typical trip level	About 4 to 6 mA of leakage for personnel protection	Based on arc patterns, not a fixed current	Both behaviors
Where required	Wet and damp areas such as bathrooms, kitchens, garages and outdoors, set by the code	Many living areas in homes, set by the code	Where both are required, for example a kitchen
Form	Receptacle or circuit breaker	Circuit breaker, or in some cases a receptacle	Circuit breaker, or a combination of devices
Not covered	Arcs between the hot and the neutral that do not leak to ground	Shock protection for a person	Overload and short circuit, which the breaker part still handles

Why one does not replace the other

A GFCI looks at leakage to ground. A damaged cord that arcs between the hot and neutral conductors leaks nothing to ground, so a GFCI does not see it.
An AFCI looks for arcing. A person touching a live part while standing on a damp floor creates a leakage current that an AFCI is not designed to detect at the level that matters for shock.
A dual-function breaker covers both, but the receptacles beyond it may still be required to be GFCI protected, depending on the code and the product.

How to choose

Check the code edition adopted where the work is built. It lists which locations need GFCI, AFCI or both.
For a location that needs both, use a dual-function breaker or a pairing that the manufacturer lists for it.
Consider a combination of an AFCI breaker and a GFCI receptacle where the breaker is hard to reach.
Check for compatibility with the equipment, because some loads can cause nuisance trips.

Common mistakes

Assuming that an AFCI protects against shock, or a GFCI against fire from arcing.
Ignoring nuisance trips instead of finding their cause. Repeated trips can be a sign of a real fault.
Skipping the monthly test button on the device.
Using the requirements of an old code edition for a new installation.

Related tools and labs

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Questions

Why does my AFCI trip with a vacuum cleaner?

Some motors with brushes produce arcing that looks like a fault. Newer devices distinguish better, but a real wiring fault can also be the cause. Test with other loads.

Do GFCI and AFCI protect equipment?

They are designed for people and for fire. Ground-fault protection of equipment uses higher trip levels, and is a separate device.

Educational material. Examples use simplified, hypothetical inputs and are not a design, a construction document or professional engineering advice. Confirm requirements with the codes and standards adopted where the work is built and with a licensed engineer.

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