For enhanced safety, the front and rear seat shoulder belts of the Hyundai Ioniq 5 have pretensioners to tighten the seatbelts and eliminate dangerous slack in the event of a collision and force limiters to limit the pressure the belts will exert on the passengers. The Toyota Prius doesn’t offer pretensioners for its rear seat belts.
Both the Ioniq 5 and Prius have child safety locks to prevent children from opening the rear doors. The Ioniq 5 has power child safety locks, allowing the driver to activate and deactivate them from the driver's seat and to know when they're engaged. The Prius’ child locks have to be individually engaged at each rear door with a manual switch. The driver can’t know the status of the locks without opening the doors and checking them.
When descending a steep, off-road slope, the Ioniq 5’s standard Downhill Brake Control allows you to creep down safely. The Prius doesn’t offer Downhill Brake Control.
The Ioniq 5 Limited has a standard Surround View Monitor to allow the driver to see objects all around the vehicle on a screen. The Prius only offers a rear monitor and front and rear parking sensors that beep or flash a light. That doesn’t help with obstacles to the sides.
The Ioniq 5 has a standard blind spot warning system that uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them and moves the vehicle back into its lane. Only the Prius LE/XLE/Limited offers a blind spot warning system.
To help make backing out of a parking space safer, the Ioniq 5 has standard Rear Cross-Traffic Collision Warning and Rear Cross-Traffic Collision-Avoidance Assist automatically engages the brakes to help avoid a collision. Only the Prius LE/XLE/Limited offers Rear Cross Traffic Alert.
Both the Ioniq 5 and the Prius have standard driver and passenger frontal airbags, front and rear side-impact airbags, side-impact head airbags, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, lane departure warning systems, rearview cameras and driver alert monitors.
The Hyundai Ioniq 5 weighs 803 to 1708 pounds more than the Toyota Prius. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.
Instrumented handling tests conducted by the National Highway Traffic Safety Administration and analysis of its dimensions indicate that the Ioniq 5, with its five-star roll-over rating, is 2.4% less likely to roll over than the Prius, which received a four-star rating.
For its top level performance in IIHS driver and passenger-side small overlap frontal, moderate overlap frontal, side impact, roof strength and head restraint tests, its standard vehicle-to-vehicle front crash prevention system, its standard vehicle-to-pedestrian front crash prevention system, and its standard headlight’s “Good” rating, the Insurance Institute for Highway Safety grants the Ioniq 5 its highest rating: “Top Safety Pick Plus” for 2022, a rating granted to only 128 vehicles tested by the IIHS. The Prius last would have qualified as only a standard “Top Safety Pick” for 2019.