COROS APEX 4 Review
A durable mountain adventure watch with mapping, exceptional battery life, and a premium finish.
October 15th, 2025
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Our Verdict
The COROS APEX 4 GPS watch is designed for outdoor adventures, including mountain climbing, trail running, hiking, and skiing. The APEX 4 has a comprehensive suite of activity profiles, performance metrics, and training programs to track your progress and provide motivation. The watch’s exceptional battery life makes the APEX 4 an excellent option for endurance athletes, such as thru-hikers and ultramarathon runners.
The APEX 4 is a significant upgrade from the APEX 2 and APEX 2 Pro. The upgraded Ambiq Apollo processor allows for significantly improved mapping capabilities, now with street/trail names and points of interest (POI). The new processor is 30 times faster, allowing for lag-free map panning and zooming. There is a built-in speaker and dual mics for receiving calls while on the move (when connected to a smartphone). The new MIPS (Memory in Pixel) always-on display significantly improves battery life over the APEX 2 and 2 Pro.
The COROS APEX naming convention may cause some confusion. Previously, the
APEX 2 and 2 Pro had different sizes and capabilities. With the APEX 4, COROS is eliminating the “Pro” distinction. The APEX 4 comes in two sizes (42 mm and 46 mm). Both sizes have the same finishes and capabilities. There is no APEX 3. COROS stated they want to sync the APEX naming convention with the COROS PACE watch series. We assume that this means that there will be a COROS PACE 4 released in the near future.
With the APEX 4, and the recently reviewed NOMAD watch, COROS is leaning into the idea of adventure journaling to make it easy to document an activity beyond the basic metrics, such as time and distance, to capture sounds, visuals, and emotions of an activity. The adventure journaling feature makes it easier to share with friends, family, and social media.
I have had the opportunity to use the COROS APEX 4 for several weeks on hikes, walks, bike rides, and as my daily activity tracker. I have been impressed with the APEX’s suite of features, customizability, and the ease of use of the COROS app. I think it is an excellent adventure watch and an exceptional value.
COROS APEX 4
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Specs
Display: 3rd generation Memory in Pixel (always on)
Display size: 1.3” (46mm) / 1.2” (42mm)
Touchscreen: Yes
Weight: 64g (46mm) / 56g (42mm)
Solar charging: No
Battery life: 46mm - 53 hours (all satellite systems) / 24 days (daily use)
42mm - 34 hours (all satellite systems) / 15 days (daily use)
GPS: Yes
Altimeter: Yes
Compass: Yes
Barometer: Yes
Navigation: Yes
Mapping: Yes
Water resistance: 5 ATM
Charging cable: COROS proprietary adapter with a USB-C cable
Smartphone compatibility: iPhone and Android
Warranty: 2 years
What We Liked
Adventure journaling. The APEX 4 makes it very easy to add waypoints (e.g., water sources, camping sites, turns), voice notes, photos, and videos to an activity. In the app, the notes and photos are shown on your route at the precise location where you took the note or photo. You can easily share your activity, even if others don’t have the COROS app. There is also an option to view a 3D flyover of your route.
I look forward to using this “adventure journaling” feature on my next thru-hike or bikepacking trip.
Battery life. COROS watches are renowned for their excellent battery life, and the APEX 4 is no exception. The watch can navigate a multi-day backpacking trip without needing to be charged.
COROS app. The COROS app makes it easy to customize watch faces, data fields, button functionality, and alerts.
Sapphire Crystal lens. The APEX 4 has a Sapphire Crystal lens. Sapphire Crystal is incredibly durable and scratch resistant. I have never scratched a sapphire lens despite years of rugged use.
Charging system. COROS utilizes a proprietary A2 adapter that connects to a USB-C cable (not included, but COROS will provide a complimentary USB-C cable upon request). COROS has designed the A2 adapter to provide a crisper, more secure fit with the watch. This addresses the issue of poor charging connections I’ve had with COROS and Garmin watches.
What Could Be Better
Music. COROS watches, including the APEX 4, feature music storage and playback; however, they do not support streaming services like Spotify and Apple Music. MP3 files must be uploaded to the phone. This means that many folks will not be able to use the watch for music or podcast storage and playback, as many have moved away from owning MP3 files.
Navigation features. COROS only offers a limited number of navigation data fields and screens. Turn-by-turn navigation is available, but distance remaining and ETA can not be added to customized data screens. There is a simple “distance and ascent remaining” data screen when navigating a route. But I would like to add these fields to a multi-field data screen with other metrics, which isn’t currently possible.
COROS lacks a detailed view of each climb on a route. Garmin offers a detailed view of each climb, including length and grade. During the climb, you can see your progress. Garmin’s ClimbPro is one of my favorite features. I wish COROS offered something similar.
Turn-by-turn directions issues. During my testing, I have had issues with turn-by-turn directions. Routes imported from Ride With GPS lack turn-by-turn directions. Routes imported from Gaia GPS or created in the COROS app occasionally display “phantom turns.” The watch tells me to turn when a turn does not exist or to turn in the wrong direction. It also occasionally skips turns when showing the next turn coming up (see photo below). The actual route line is accurate, however.
No LCD Flashlight. A built-in LED flashlight is one of my favorite features for the Garmin Instinct and fenix watches. The flashlight eliminates the need to grope for a headlight in a tent and is perfect for navigating to the bathroom at night.
APEX 4 Upgrades
Improved mapping. The landscape topographic maps now have street/trail names. The 30-times-faster processor provides lag-free zooming and panning.
3rd generation MIPs display. The new MIPs display allows for better contrast and visibility in different light conditions. It also significantly improves battery life over the LCD display in the APEX 2 series.
Speaker and dual mics. The speaker provides audio alerts and allows for hands-free calling when paired with a smartphone. The dual microphones allow you to easily provide voice pins and waypoints.
Dual frequency GPS. Both APEX 4 sizes have dual frequency GPS. Previously, the APEX 2 did not offer dual frequency GPS. It was available in the 2 Pro.
Water depth sensor. The watch includes a water depth sensor that will show your depth (note: the watch is not intended for scuba diving. The APEX 4 is rated to a depth of 50 meters).
New button layout. The buttons have been positioned to reduce accidentally pushing a button during an activity.
Comparison Table
The COROS APEX 4 is poised to challenge the Garmin fenix in the high-end adventure watch category. The APEX 4 and fenix series both provide the full complement of activity tracking and smartwatch features with mapping and high end finishes such as Sapphire Crystal lens and titanium bezels.
The Garmin fenix does provide some additional features, such as access to music streaming services, an LED flashlight, and advanced navigation features such as ClimbPro and pre-loaded ski maps. However, the APEX 4 is less than half the cost of the base Garmin 8.
The table below compares the COROS APEX 4 with the Garmin fenix 8 (Solar and AMOLED versions). Additionally, we include the COROS PACE Pro, NOMAD, and APEX 2 and 2 Pro for comparison purposes.
| Features | COROS APEX 4 (46mm) | COROS APEX 4 (42mm) | COROS NOMAD | Garmin fenix 8 (47mm)* | COROS PACE Pro | COROS APEX 2 Pro | COROS APEX 2 |
|---|---|---|---|---|---|---|---|
| Price | $479 | $429 | $349 | $1,100 | $349 | $449 | $449 |
| Lens Material | Sapphire Glass | Sapphire Glass | Mineral Glass | Sapphire | Mineral Glass | Sapphire Glass | Sapphire Glass |
| Display | Memory In Pixel (MIP) | Memory In Pixel (MIP) | Memory In Pixel (MIP) | AMOLED or solar | AMOLED | LCD Memory | LCD Memory |
| Display Size | 1.3" | 1.2" | 1.3" | 1.3" | 1.3" | 1.3" | 1.2" |
| Resolution | 240 x 240 pixels | 260 x 260 pixels | 260 x 260 pixels | 416 x 416 pixels | 416 x 416 pixels | 260 x 260 pixels | 240 x 240 pixels |
| Watch Mode | COROS APEX 4 - 46mm | COROS APEX 4 - 42mm | COROS Nomad | Garmin fenix 8 (47mm) AMOLED1 or Solar2 | Garmin Instinct 3 Solar 50mm1 | Garmin Instinct 3 AMOLED 50mm2 | COROS Pace Pro2 | COROS APEX 2 | COROS APEX 2 Pro |
|---|---|---|---|---|---|---|---|---|---|
| Smartwatch Mode (Daily Use) | Up to 24 days | Up to 15 days | Up to 22 days | Up to 16 days (AMOLED)/28 days with solar | Up to 40 days (unlimited with solar) | Up to 24 days | Up to 20 days | Up to 13 days | Up to 21 days |
| All Satellite Systems GPS | Up to 53 hours | Up to 34 hours | Up to 50 hours | Up to 38 hours (AMOLED)/59 hours (Solar) | Up to 40 hours/80 hours with solar | Up to 32 hours | Up to 38 hours | Up to 25 hours | Up to 41 hours |
| All Satellite Systems + Dual Frequency* | Up to 41 hours | Up to 26 hours | Up to 34 hours | Up to 35 hours (AMOLED)/43 hours (Solar) | Up to 34 hours/60 hours with solar | Up to 30 hours | Up to 31 hours | NA | Up to 24 hours |
Features
The COROS APEX 4 is a fully functional adventure watch with GPS navigation, activity and health tracking, and all the smartwatch features one expects in their everyday watch.
Activity Tracking
The APEX 4 includes activity profiles for over 50 activities, from hiking to frisbee. There are profiles for indoor activities, such as strength training and Pilates, as well as water-based activities like whitewater rafting and speed surfing. There is even a triathlon activity profile.
The specific data fields within each activity profile can be customized. You can also have multiple data fields for each activity. It is easy to swipe between data fields during any activity.
You can also set up alerts within an activity, such as speed, cadence, heart rate, or when to eat/drink.
Health Tracking
The COROS APEX 4 has a full complement of health tracking features, including the following:
Optical heart rate
Barometric altimeter
SpO2 (Blood Oxygen) monitor
Electrocardiogram sensor
Sleep tracking
Optical pulse oximeter
Heart rate variability (HRV) tracking
Smartwatch Features
The APEX has all the features one would expect from a smartwatch. Below is a partial list of smartwatch features:
Notifications
Stopwatch
Timer
Find my watch
Find my phone
Alarm
Daily alerts (active calories, storm warning, etc.)
MP3 music storage (note: COROS does not support streaming services, such as Spotify or Apple Music. MP3 files must be uploaded to the watch from your computer.)
Mapping and Navigation
The COROS APEX 4 provides the essential ABC (altimeter, barometer, and compass) features necessary for an adventure, especially for a hiking watch. In addition, the APEX 4 has All Systems Satellite (GPS, GLONASS, Galileo, Beidou, QZSS). All Systems uses more than one system at once to improve accuracy. The APEX 4 also features dual frequency and All Systems, providing even greater accuracy in deep canyons or dense urban environments.
Note: All Systems is the default setting on the APEX 4. Dual-frequency + All Systems uses more battery. It’s not possible to use only one system, such as GPS only, to preserve battery life.
COROS provides free global mapping. The COROS app features a Map Manager that allows you to easily download maps for your specific region. The landscape topographic maps provide street names, points of interest (POI), and differentiate between roads and trails. This addresses a significant flaw in mapping on the APEX 2 and 2 Pro watches.
The more detailed maps will also be rolled out to the COROS PACE Pro, which also has the upgraded processor. We assume that, as other COROS watches get the improved processor, they will also have the more detailed maps.
The APEX 4 provides turn-by-turn directions and alerts you if you depart from the route. The watch’s dial makes it easy to zoom in and out on the map.
When navigating a route, there is a data field showing the remaining distance and ascent.
Routes are easy to create and edit within the COROS app. Additionally, you can import routes from third-party apps, such as Strava, Ride With GPS, or Gaia GPS. The watch provides turn-by-turn directions. I was impressed with how easy it was to zoom or pan the map on the watch while navigating.
Extender
The extender feature allows you to view your route in the COROS app during an activity. You can easily pan or zoom on the map on your phone. There is also a button to open your phone’s camera or leave a pin. The route shows the photo’s location.
Environment
The APEX 4 offers real-time environmental data, such as weather, wind, air pressure, and moon/sun movements, as activity data fields. Currently, COROS only offers the Environment feature on the APEX 4.
Adventure Journaling
COROS is leaning into the concept of adventure journaling with the APEX 4 and the COROS app. The idea is to enable the user to easily add photos and pins (waypoints) to an activity. You can also leave voice notes or reminders to yourself. (note: voice pins are show on the map of your activity and on the Explore page of the COROS app.)
Photos and videos. The COROS app shows all the photos and videos taken during an activity. You can choose which photos you want to sync to the route. These photos will then appear along the route.
Pins (Waypoints). The “action button” can be configured to add a pin when pressed during an activity. This enables you to add a voice note or waypoint along the route. The voice memo translates keywords into specific waypoints. For example, if you say “water source,” a water waypoint will appear on the route.
Activity sharing. After an activity, it is easy to share the activity with friends and family, including all photos and pins, even if they don’t have the COROS app.
I have been impressed with the adventure journaling features. I will use these features on my next thru-hike.
COROS App
COROS has a phone app for tracking activities and health metrics. The app can also be used to configure the APEX 4’s watch face and customize activity data fields.
I found it easy to create and edit routes in the app. You can also upload routes created in Strava, Ride With GPS, AllTrails, and Gaia GPS.
Where to buy the COROS APEX 4
REI Co-op
Pros: 100% satisfaction policy for 1 year; up to 10% dividend for members.
COROS
Pros: Manufacturers often have colors not available elsewhere
Who Should Buy the COROS APEX 4?
The COROS APEX 4 is designed for outdoor enthusiasts and endurance athletes seeking an adventure watch with exceptional battery life and premium finishes. The All Systems and dual-frequency GPS enable accurate activity tracking and navigation. I think the APEX 4 is particularly well suited for folks who want a rugged outdoor watch with all the capabilities of the COROS NOMAD, with a high-end aesthetic.
About the Author / Why You Should Trust Us
Mike Unger left his high-stress corporate job to thru-hike the Pacific Crest Trail in 2006. That experience forever changed him, and he purposefully re-arranged his life to allow for as much adventuring as possible.
Today, he’s closing in on 28,000 miles on North American long trails. He is one of a handful of people who is a Double Triple Crowner, having hiked the Appalachian Trail, Pacific Crest Trail, and Continental Divide Trail each—twice. He’s also hiked more obscure routes like the Ouachita Trail, Oregon Desert Trail and was part of the group that set the First Known Time on the Blue Mountains Trail.
He’s also picked up another passion along the way: long-distance bicycle touring, including the 2,700-mile Great Divide Mountain Bike Route and 1,850-mile Pacific Coast route. When he’s not hiking or biking, he’s probably planning his next trip and/or researching gear.
You can read all articles by Mike Unger here.
