Description
Frequently Asked Questions
How does Swimtraxx One attach to my goggles?
Swimtraxx One clicks onto the strap of your swimming goggles. Place it on the right side — this is essential for the algorithm to work correctly. It fits most standard goggles, no special equipment needed. For goggles with extended visors (e.g. Arena Cobra) where the sensor can’t make skin contact, you can also wear it under your swim cap.
How accurate is the heart rate measurement?
The optical heart rate sensor sits at the right temple, which is one of the most reliable locations for underwater optical HR measurement. Skin contact between the sensor and your temple is required for accurate readings. This head-mounted position outperforms wrist-based sensors that struggle with water flow interference during swimming.
What metrics does it track?
In the pool (9 parameters): heart rate, lap time, stroke type (auto-detected: fly, back, breast, free), stroke rate, stroke count, breath count, turn time, underwater time, and stroke length.
In open water (5 parameters): heart rate, stroke rate, stroke count, stroke type, and breath count.
Is there a subscription fee?
No. Swimtraxx One is a one-time purchase. The Swimtraxx Hub app and all features are included free — no monthly fees, no premium tiers, no hidden costs. Ever.
Can my coach see my data live?
Yes. The Swimtraxx Hub app connects wirelessly to multiple Swimtraxx One devices simultaneously. Coaches see live heart rate, pace, stroke data, and more for every swimmer in the water, right on their iPad at the pool deck.
How long does the battery last?
Up to 8 hours of continuous tracking. Charging takes about 2 hours via the magnetic charging cable.
Will I feel it while swimming?
At 12.7 grams, swimmers consistently report forgetting it’s there after the first few laps. It was co-developed with Olympic-level swimmers including Femke Heemskerk and Pieter Timmers to ensure zero interference with technique and hydrodynamics.
Can I use it in races?
Yes. Swimtraxx One is World Aquatics approved for racing under Rule SW 15.3 — the first and only platform to provide comprehensive swim tracking capability in-race.
Does it work in open water?
Swimtraxx One can be worn in open water and will track heart rate, stroke type, stroke rate, stroke count, and breath count. However, without pool walls there is no lap detection — your swim is recorded as one continuous lap. There is no GPS, so distance cannot be tracked outdoors. Swimtraxx One is designed primarily for pool swimming.
What happens to my data?
Your data syncs to the Swimtraxx Hub app after each session. You own your data. Review detailed analytics, track progress over time, share automatically with your coach, or sync to Strava.
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Customer –
Perfect
Small, compact and does what it should.
Karl –
Compact and wearable
I no longer need to wear a watch and still get more data. Permanently attached to my goggles. Easy.
Maaike –
Great support
I use it during every swim after support walked me through setting up Swimtraxx One on my phone.
Johan –
Works nice!
I tried Swimtraxx the same day I recieved it, worked nice and got data into the ipad on the pool deck where my friend watched as I did some laps, some sprints and a little bit of drills.
Thomas –
Swimtraxx One keeps getting better!
Swimtraxx One is an exceptional swimming tracker that continuously evolves with each update. The team's unwavering dedication to improvement shines through in its remarkable accuracy and user-friendly applications. For swimmers seeking enhanced performance and reaching new heights, I truly recommend
Tomas –
Decent
Heart rate is ok, not always consistent for me. The lap times are accurate which is nice. For the price I expected a bit more but its not bad.
Hannah –
Nice
Good heart rate accuracy. The app is ok, nothing fancy but it works. Would like to see a dark mode at some point.
Robert –
Nice device
Does what it says. Heart rate works well, the whole thing is really light. Would give 5 stars but I had some trouble connecting it to the app the first time. After that no problems.
Thijs –
Works great
I swim 4x a week and this gives me useful data every time. Heart rate, lap times, stroke info. Happy with it.
Rik –
Disappointing
Had high hopes but the app kept losing the connection when I tried to sync. Took me 10 minutes after every swim to get the data off. The actual swimming data looked fine when it finally transferred. Maybe I had a bad unit or something.
Pieter –
Finally accurate swim data
Been looking for something like this for a while. Heart rate is consistent and you barely notice it on your goggles. Lap times are correct too. Really happy.
Markus B. –
Best solution
Swimtraxx is accurate and reliable and is more accurate and reliable than what we used before. Overall, Swimtraxx is more intuitive and easy to setup and the live feedback on pool deck during training by Swimtraxx is very helpful
Anna –
Great christmas gift
Bought this for my husband who swims a lot. He loves it, says the heart rate data is actually reliable unlike his old watch. Setup took 5 minutes.
Emma –
Great product
My partner got me this for christmas and I use it every session now. The heart rate tracking is really accurate and its so small you forget about it. The app could look a bit nicer but it does the job.
Tim de Jong –
Top
Works perfectly. HR accurate, lightweight, app is clear. Happy with it.
Daan –
Solid
Works as advertised. Accurate HR, good app. No complaints.
Michelle –
Didn’t work well for me
I couldn’t get consistent heart rate readings no matter how I positioned it. Lap times were fine but the HR was the main reason I bought it. Maybe it just doesn’t suit my head shape or goggles. The product seems well made at least.
Brice-Henri T. –
Accuracy
Swimtraxx is very accurate when we are swimming. However, it is completely lost when we are doing drills. So the data are not correct as mentioned on the website. However, I was expecting maybe a possibility to update the workout manually and add those drills but it is not possible apparently.
Lotte M. –
Very good
Accurate heart rate, easy to use. Took me one session to figure out the best position on my goggles but after that its been great. Only reason for 4 stars is that I wish there was more detail in the app about my technique.
Wim –
Good product
I’m 62 and swim for fitness. This is easy to use and the heart rate helps me stay in the right zone. Took a few swims to get used to having something on my goggles but now its fine.
Chris B. –
Decent but not for everyone
Heart rate works ok but I had issues with it reading consistently. Might be my goggle strap, not sure. The data is interesting when it works. Maybe I need to experiment more with the placement.
Vera –
Love it!
So easy to use. Clip it on, swim, check your data after. Heart rate is consistent every session.
Sandra –
So much better than expected
Honestly didn’t expect much from something this small but the heart rate is very accurate and the app shows everything clearly. Been using it for 3 months now, no issues.
Fleur –
Mixed feelings
Some sessions the data is great, other sessions the heart rate drops out for a few laps. Not sure if its my goggles or my swim cap pushing on it. When it works its really good though.
Nathalie V. –
Great product
Lightweight, accurate, easy to set up. Not much more to say really. Does what it promises.
Jonas –
Really good
Bought this after trying a friend’s. The heart rate is much better than my old watch gave me in the water. Lightweight and the app is nice.
Jolien –
Really like it
Heart rate tracking is the best I’ve tried in the water. Only small thing is that the charger cable is a bit short. Otherwise very happy.
Wouter –
Recommended by my coach
My coach uses these for the whole squad. I was sceptical at first but the data is really useful. You can see your heart rate, stroke rate, all that. And it syncs to strava which I like.
Jan-Willem –
Good product, battery could be longer
Accuracy is really good, no complaints there. I swim about 6 times a week and need to charge it every 4-5 days which is fine but would be nice if it lasted a bit longer. Otherwise excellent.
Bart –
Ok but expected more from the app
The device is fine, heart rate seems accurate enough. But the app feels a bit basic for the price. I expected more graphs and analysis. The data is there but the presentation could be better.
Ilse –
Happy swimmer
Love seeing my heart rate data after each session. The device is super light and I dont even notice it. Already recommended it to a few people at my club.
Stefan K. –
Good device
Does what it should. HR is reliable and the lap times are accurate. Sometimes the bluetooth takes a moment to connect but nothing major. Happy overall.
Marco R. –
Exactly what I needed
Bought this on black friday. I swim 3-4 times a week and wanted actual useful data from my sessions. The heart rate and lap times are spot on. My coach can see it live too which is a nice bonus.
Koen V. –
Best swim gadget I own
Small, light, accurate. The app is straightforward and I can share sessions with my coach. What more do you need.
Femke –
Good but app could be better
The device itself is great, HR is accurate and I like seeing my data. But the app could use some work, sometimes it takes a while to sync and the graphs are a bit basic. Still very happy overall though.
Lars –
Super happy with this
Got this for christmas. Heart rate is really accurate compared to my watch on land. You don’t feel it at all on your goggles. Very happy with the purchase.
Ruben –
Got one for the whole family
Bought one for myself first, now my wife and son both have one too. We all swim at the same club and its fun comparing our data after practice. Heart rate is really reliable on all three.
Eline –
Love it
Works great, can finally see my heart rate after training. The app is easy to use too.
Maartje –
Perfect
Simple, works well. Exactly what I wanted.
David –
Way better than a watch
I had a Garmin before and the heart rate was all over the place in the water. This is so much more consistent. Also nice that its so light, doesnt bother me at all.
Marleen –
Good, not perfect
The heart rate is accurate which is the main thing. I just wish the app showed a bit more analysis, like trends over time or something. The device itself is great though.
Stijn –
Very impressed
Heart rate is accurate, lap times are correct. I compared it to the pace clock and everything matches. Really light too, doesn’t move around on my goggles at all.
Fredrik –
I’m happy with my Swimtraxx unit. I wanted something to track my pace, total distance, heart rate and stroke rate without getting a smart watch. These are the metrics I want to keep track of before I have my summer open water racing, and I don’t get information overload as a smart watch potentially could. It would be nice if I could use the unit for open water as well. Now I can upload my session to TrainingPeaks to analyse my efforts over time and estimate training load.