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An AED symbol is the sign that tells a rescuer where an automated external defibrillator is. After reading this page you should be able to recognise the universal sign, understand what its design and tested standards mean, and tell how regional versions differ.
This page describes products and general use; it is not medical advice.
What the AED symbol is
The AED symbol is a safety sign that marks the presence of an automated external defibrillator (AED). The International Liaison Committee on Resuscitation (ILCOR) approved a universal AED sign so that an AED can be identified quickly in a cardiac arrest. Who uses it: building and facility managers who mark equipment, first aid and safety officers, sign manufacturers, and bystanders who need to find a device. For what the device itself is, see what a defibrillator is and how it works.
How the universal sign was designed and tested
ILCOR’s AED Signage Task Force proposed the universal sign, and ILCOR approved it unanimously. According to the ILCOR letter, the sign follows three international standards:
- ISO 7010 for the form and shape of safety signs.
- ISO 3864-3 for colours and symbols.
- ISO 9186-1 (rev. 2007) for testing comprehensibility; ILCOR reports the chosen design proved superior to alternative designs in that testing.
ILCOR intended national resuscitation councils and AED and signage manufacturers to adopt the sign worldwide. Resuscitation Council UK (RCUK) dates ILCOR’s approval of the universal sign to 2008.
Sign versions compared
The universal sign is not the only AED sign in use. RCUK states that the ILCOR sign is “similar to, but not the same as” the UK version. The table lists the versions described by the sources below.
| Sign | Origin | Key features stated by the source |
|---|---|---|
| ILCOR universal AED sign | ILCOR AED Signage Task Force; approved 2008 per RCUK | Designed to ISO 7010; colours and symbols to ISO 3864-3; comprehensibility tested to ISO 9186-1 |
| Original UK standard sign (2006) | RCUK Basic Life Support/AED Subcommittee | Lightning bolt symbol; met EU colour, shape and content requirements; accepted by the UK Health and Safety Executive (HSE) |
| Redesigned UK sign | RCUK, after public surveys in 2015 | Lightning bolt replaced by a stylised ECG heart trace; wording “Defibrillator – Heart Restarter”; a figure lying on their back shows pad placement; accepted by HSE |
| BHF/RCUK standard defibrillator sign | British Heart Foundation with Resuscitation Council (UK) | “Heart starter” symbol replacing the old lightning bolt; A5 (148 x 210 mm) with adhesive backing |
RCUK reports that a July 2015 survey of 1,895 adults found fewer than half recognised and understood the 2006 sign, and a further public survey in December 2015 gathered 2,115 responses; the redesign followed.
Arrows, letters and wording on AED signage
ILCOR says the symbol may be combined with an arrow, or with the letters “AED” (or the equivalent in other languages). It does not encourage using the full word “defibrillator” on a sign, because the full text is harder to see from a distance. The RCUK poster messages that accompany its sign state that anyone can use an AED without prior training, that it is easy to use by following the instructions, and that it is for an unconscious person who is not breathing normally.
What each sign marks and where it points
ILCOR describes four uses for the universal sign:
- the presence of an AED;
- the AED’s location within a room;
- a container holding an AED for public use;
- the direction to reach an AED.
The stated purpose in each case is to help people identify an AED rapidly during a cardiac arrest. The BHF describes its sign as marking public access defibrillators and workplace defibrillators and making it easier for rescuers to locate a defibrillator quickly. For how facilities plan and maintain devices, see AED program management and the AED buying guide for facilities. Facilities that stock related emergency supplies can browse emergency and trauma response supplies.
Common mistakes
- Relying on the word “defibrillator” alone. ILCOR notes the full text is poor for visibility at a distance; pair a symbol with an arrow or “AED”.
- Assuming one design everywhere. The UK and ILCOR versions differ, so a rescuer may meet either.
- Assuming everyone recognises the symbol. RCUK’s 2015 survey found fewer than half of respondents understood the 2006 sign.
- Looking for one fixed layout. ILCOR allows the symbol alone, with an arrow, or with the letters “AED”; see AED requirements for gyms for a facility example.
FAQ
What does the AED symbol look like and mean?
It is the sign approved by ILCOR to show that an automated external defibrillator is present, where it is, or which way to go to reach it. Regional versions differ in artwork, for example the UK sign described above.
What is AED signage?
AED signage is any sign that marks an AED, its cabinet or the route to it. ILCOR allows an arrow or the letters “AED” to be combined with the symbol.
Is the AED sign the same in every country?
No. ILCOR intended worldwide adoption of its sign, but RCUK notes the UK sign is similar to, but not the same as, the ILCOR version.
How is an AED different from a manual defibrillator?
See manual defibrillator vs AED.
Sources
- ILCOR, AED Sign letter (R.W. Koster, chair, ILCOR AED Signage Task Force): https://ilcor.org/data/AED_Sign_letter_ILCOR_AED_sign_final_V20101102.pdf. Checked 30 October 2026.
- Resuscitation Council UK, Guidance: Standard sign for AEDs: https://resus.org.uk/library/additional-guidance/guidance-defibrillators/guidance-standard-sign. Checked 30 October 2026.
- British Heart Foundation, Defibrillator sign: https://defibrillators.bhf.org.uk/defibrillator-sign. Checked 30 October 2026.
