Daysy vs Lady-Comp: Which is Right For You?

by Feb 18, 2021

Countless women have turned to apps and digital trackers to take the guesswork out of fertility. Whether you are tracking your cycle, trying to conceive, or using cycle tracking for other reasons like contraception, the options can be overwhelming. How do you know which one is right for you and whether it will fit your needs?

daysy vs lady comp

Valley Electronics, a leader in women’s health technology, offers both the Daysy and the Lady-Comp fertility trackers. Read on as we compare the Daysy vs Lady-Comp, with details on how they work, stand out features, and where each product really shines.

Getting to Know the Products

Both the Daysy and the Lady-Comp offer impressive features that proclaim reliable, precise technology for natural fertility control. Developed and produced by Valley Electronics, these products are based on more than 30 years of experience in developing and distributing fertility trackers.  With headquarters in Switzerland and production in Europe, Valley Electronics seeks to empower women through fertility technology, and they tout themselves as a dependable partner for the health conscious woman.

Although based on similar technology, the Daysy and Lady-Comp differ in a few key areas. Depending on your goals, one may work better for you than the other (read our full Daysy review here).

If you are looking for the most comprehensive and in-depth look at your cycle and fertility, the Lady-Comp can’t be beat as it offers more in depth features and analysis than the smaller Daysy. But don’t count the Daysy unit out, it may not pack the feature punch of the standalone Lady-Comp, but it does offer a companion app that allows you to view past data right on your smartphone.

Your preferences, the reason you’re tracking your cycle, and how you plan to use the information will ultimately make the decision of which unit is right for you.


  • Small, lightweight, and easy to use
  • Companion app that allows you to see past data
  • Lower price point than Lady-Comp
  • Unit only displays fertility status light, must use companion app to see other data
  • Small, delicate unit


  • A unit display so you can see fertility status and other data together
  • Includes an alarm you can set with volume controls
  • Intuitive user interface and digital display
  • Predicts fertility for next six days
  • Battery powered to eliminate cords
  • Higher price than Daysy
  • No connected app, all data on unit

Features Face to Face

Both the Daysy and the Lady-Comp devices use the basal body temperature (BBT) method to monitor your fertility. However, while they may use the same method, they differ in features as well as how they present the data.

Hormone Tracking

Both of these units offer a hormone-free alternative to birth control and family planning, but unfortunately neither unit is capable of actually measuring your hormones. They work by detecting changes in your basal temperature that correlate to hormone changes, like the LH surge that triggers the start of your fertile window.

To track your numeric LH and estrogen hormone levels you would need a tracking tool like Mira that captures more than just temperature

Fertility Tracking

Based on an intelligent algorithm and years of research, both the Daysy and the Lady-Comp calculate when you are fertile and when you are not. Daysy will display your fertility status using a red or green indicator light as well as provide further insights, including predictions, on the app.

Using the same algorithm, the Lady-Comp also determines which phase of your cycle you are in and whether you are fertile or not. Based on your daily temperature readings and the length of your past cycles, the Lady-Comp calculates your current fertility status and displays which phase of your cycle you are currently in.

There is no clear advantage of one device over the other when it comes to fertility tracking since they both calculate your daily fertility status. However, we believe that Daysy has a slight advantage over the Lady-Comp because of the companion app, where you can see past data, record your own notes, and see forecasts.

Ovulation Tracking

A rise in basal body temperature correlates to ovulation and both the Lady-Comp and the Daysy use this measurement to calculate and confirm your fertile days and predict ovulation. Although both devices track ovulation, the Lady-Comp requires you to navigate through the unit’s display to see past data.

On the other hand, Daysy, with its companion app, offers better historical tracking since your information is readily available on your smartphone and is easy to see. Although it still tracks ovulation, the Lady-Comp falls short in easy to access historical data when compared to Daysy.

Digital Display

The Daysy is a simple and straightforward fertility tracker that uses a light system on the device to indicate whether you are fertile or not. There is no digital display and all data must be transferred via bluetooth to the companion app.

Conversely, this feature is where the Lady-Comp shines; daily fertility status and historical data can be displayed right on the unit thanks to the digital display. Detailed cycle statistics as well as many other measured values are easily read on the minimalist display.

App Availability

Although the Lady-Comp does offer data transfer to a PC via a USB cable, there is no companion app that goes with the device. Unless you have transferred your data, you need the device to see any details about your cycle.

The Daysy is the clear winner in this department since it connects via bluetooth to its own app and data is easily shared with others, like your partner or doctor. You do not need the device to review anything and it is always available to you on your smartphone or tablet.

However, given the lack of display, you are forced to use the app whether you want to or not, especially since the Daysy needs access to your phone to calibrate your calendar. In our opinion, while it may be a cumbersome step for some, having a companion app is a clear win in the age of digital fertility tracking.

Stand Out Features

Both the Daysy and Lady-Comp share a lot of features but we to want to point out 2 that make each device unique:

  • Alarm:  The Lady-Comp offers a built in alarm that you can use to wake you for your temperature reading. Not only is this a convenient feature, but it helps to develop your personal history by using the device as regularly as possible and making it a habit.
  • App:  The Daysy makes very good use of a companion app that not only supports the device, but allows you to add additional information useful for fertility. You can add notes, track intercourse, and share your data in addition to technical features like checking the battery level on your actual device or turning off predictions.

Which Tracker Makes Sense for You?

Both the Lady-Comp and the Daysy fertility tracking devices offer cycle and fertility tracking through the use of the BBT method (read our full Lady-Comp review here).

And, while choosing the best device is a personal choice, we do have some input on which device works best for certain types of people:

Use Daysy if:

  • You want to track additional data (like cervical fluid changes or intercourse) that can be noted in the app.
  • You want to see and access your data from a companion app.
  • Your schedule is irregular – you don’t need to take your temperature at the same time every day with the Daysy and you need just three hours of consecutive sleep for it to work.
  • Your menstrual cycles are between 19 and 40 days in length.
  • You want to share your data with your partner, which they can access on their own phone via an app especially for partners of Daysy users.

Use Lady-Comp if:

  • You want a standalone device that doesn’t have to be connected to the internet or your smartphone to realize full functionality.
  • You want to share printouts of your data with your healthcare team.
  • You don’t want another device to charge – the Lady-Comp uses batteries.

What About Other Options?

If you’re looking for other tracking options that go beyond BBT, the Mira Fertility Plus incorporates hormone tracking to predict ovulation, keep track of cycles and identify hormonal patterns.

Mira uses a want + analyzer + app to provide a more granular look at your hormone levels in order to better predict fertility. This approach is ideal for women looking for personalized insights into when they are the most fertile as well as trends over time.

Written by Fertility Nutrition Hub

Order Your Mira Plus Today

Track your whole cycle and what is happening with your hormones. Get a larger fertile window (6 days) and clear insights. Let Mira take the guesswork out of tracking all fertile days and infertile days.