An AED (automated external defibrillator) can be used by anyone. It talks you through each step and will only shock if it detects a heart rhythm that needs it. Choosing one comes down to a few practical questions.
Fully automatic or semi-automatic?
| Fully automatic | Semi-automatic | |
|---|---|---|
| Who presses the shock? | The AED delivers the shock itself, after a warning | The rescuer presses the shock button when told to |
| Good for | Public access and untrained or occasional users | Trained responders who want control of the timing |
| Things to know | Everyone must stand clear when told | The user must press the button when prompted |
Will it be used on children?
Many AEDs use separate child pads, or a child mode or key that lowers the energy. If children may be present, such as in schools, leisure centres and family events, check how the model handles child use and keep what it needs with the AED.
Where will it live?
- Indoors: a wall bracket or an indoor cabinet, near the entrance or reception, with clear signage.
- Outdoors: a weatherproof cabinet. In cold places a heated cabinet helps protect the battery and pads.
- In a vehicle or kit bag: a carry case, and an AED with a good water and dust rating.
Running costs
The price of the AED is only part of the cost. Pads and batteries have a shelf life and need replacing, and pads must be replaced after every use. Check the cost and lifespan of both before you buy.
Other features worth considering
- CPR feedback that tells the rescuer if compressions are deep and fast enough
- Clear voice and screen prompts
- Self-tests and an easy-to-see status light
- A trainer unit for practice sessions
After you buy
Register your AED on The Circuit, the national defibrillator network, so ambulance services can direct people to it in an emergency. Check it every week. Our free AED weekly check log makes that easy.
This guide is general buying advice. Always follow the manufacturer’s instructions and current resuscitation guidance.