Philips offers two flagship lay-user AEDs at different price points — and most buyers shopping the Philips ecosystem ask the same question: when does the extra $200–$500 for the FRx pay off vs sticking with the OnSite? Short answer: outdoor environments, multi-population facilities (schools serving both kids and adults), and any application where the AED might travel or have an impact. Indoor office-only deployments stick with OnSite.
Head-to-head spec comparison
| Spec | HeartStart OnSite | HeartStart FRx |
|---|---|---|
| Price (MSRP) | $1,295–$1,495 | $1,595–$1,800 |
| IP rating | IP21 (indoor) | IP55 (outdoor) |
| Drop test | Not rated | 1.5 m (highest in class) |
| Pediatric pathway | Separate pediatric pads (M5072A) | Infant/Child Key (single pad set) |
| Warranty | 8 years | 8 years |
| Weight | 3.3 lb | 3.5 lb (lightest rugged) |
| Best for | Indoor offices, home | Schools, outdoors, athletics, and construction |
The Infant/Child Key advantage
FRx’s unique pediatric pathway: insert a small plastic key into the AED to switch to pediatric energy — using the same adult pads. OnSite requires stocking a second pediatric pad set ($129). For schools, daycare, family-friendly venues, or any facility with mixed adult+child populations, the FRx Key reduces inventory complexity by 50%.
Verdict by use case
Best for indoor offices · retail · home
Philips HeartStart OnSite
Lower cost. Indoor IP21 fine for climate-controlled environments. Larger U.S. install base. The default Philips pick for the general workplace.
Best for schools · athletics · outdoor · construction
Philips HeartStart FRx
IP55 + 1.5 m drop test = most rugged AED on the U.S. market. Infant/Child Key simplifies pediatric inventory. For any field or multi-population deployment, FRx pays back the $200–$500 premium.
Frequently Asked Questions
What’s the main difference between OnSite and FRx?
FRx adds IP55 outdoor rating, 1.5 m drop test, and the Infant/Child Key pediatric pathway. OnSite is indoor-only at a lower cost.
Is FRx worth the extra $200–$500?
For schools, athletics, outdoor, or any multi-population facility — yes. For indoor office-only deployments — no.
Can I use the OnSite outdoors?
Not recommended — IP21 only resists dripping water. Direct rain or humidity exposure can damage the unit.
What’s the Infant/Child Key?
A plastic key is inserted into the FRx to switch the shock energy to a pediatric dose. Works with the same adult pads — no second pad set required.
Do OnSite and FRx use the same pads?
No — different SKUs. OnSite uses M5071A; FRx uses SMART Pads II (989803139261).
Get hands-on AED training in under 3 hours.
Sources & References
- Manufacturer specs: Philips HeartStart OnSite (M5066A), Philips HeartStart FRx
Disclaimer: 2024–2025 MSRP.
