07/23/2026
What are joules on an AED?
You may have heard that an AED delivers a shock measured in joules, but what does that actually mean?
Think of joules as a way of measuring energy. The AED uses that energy to deliver a carefully controlled electrical shock to the heart when someone is in a life-threatening cardiac rhythm.
More joules don't automatically mean a "better" shock. AEDs are designed to deliver the right amount of energy needed to give the heart the best chance of returning to a normal rhythm.
The most important thing? If an AED tells you to deliver a shock, it's because it's determined one is needed. Just follow the voice prompts and they'll guide you every step of the way.
❤️ Fast CPR + early defibrillation can save lives!