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 $510 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 (AED Leader) | $1,589 to $1,819 | $2,099 to $2,199 |
| IP rating | IP21 (indoor) | IP55 (outdoor) |
| Drop test | Not rated | 1.5 m |
| 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 ($139). 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.
Recertified prices across all seven models
Recertified units are the same models under the same FDA premarket approvals, restored, tested and sold with a minimum three year warranty.
| Model | New | Recertified | You keep | Buy |
|---|---|---|---|---|
| Philips HeartStart OnSite | $1,589 | $875 | $714 (45%) | AED Leader or Response Ready |
| Philips HeartStart FRx | $2,099 | $875 | $1,224 (58%) | AED Leader or Response Ready |
| ZOLL AED Plus | $2,082 | $875 | $1,207 (58%) | AED Leader or Response Ready |
| ZOLL AED 3 | $2,399 | $1,150 | $1,249 (52%) | AED Leader or Response Ready |
| HeartSine Samaritan PAD 350P | $1,411 | $875 | $536 (38%) | AED Leader or Response Ready |
| HeartSine Samaritan PAD 450P | $1,761 | $875 | $886 (50%) | AED Leader or Response Ready |
| Cardiac Science Powerheart G5 | $2,157 | $1,225 | $932 (43%) | AED Leader or Response Ready |
Prices verified 30 September 2026 against the public product data of both stores. Both list identical recertified prices, so buy from whichever fits your order size: AED Leader for one to four units, Response Ready for five or more and for compliance and fleet programmes. New prices are the AED Leader list price on the same date.
The honest risk. A recertified AED is a used device. The three year minimum warranty is what makes the saving worth taking. Read recertified versus new and how to choose a refurbished AED before you decide.
Best for schools · athletics · outdoor · construction
Philips HeartStart FRx
IP55 and a drop-tested case make the FRx the more rugged of the two. Infant/Child Key simplifies pediatric inventory. For any field or multi-population deployment, FRx pays back the $510 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 $510?
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).
Both models, priced today
Prices checked 30 September 2026 at AED Leader. Each link opens our full review with the buy path.
- Philips HeartStart OnSite (M5066A) review and price$1,589 to $1,819New, 8-year manufacturer warranty
- Philips HeartStart FRx review and price$2,099 to $2,199New, 8-year manufacturer warranty
- Recertified Philips HeartStart OnSite review and price$875Save 45%Recertified, 3-year warrantyBuy at AED Leader
- Recertified Philips HeartStart FRx review and price$875Save 58%Recertified, 3-year warrantyBuy at AED Leader
Get hands-on AED training in under 3 hours.
Sources & References
- Manufacturer specs: Philips HeartStart OnSite (M5066A), Philips HeartStart FRx
Disclaimer: Prices are AED Leader list prices, checked September 2026.
