Clue vs Stardust: Which Period Tracker Fits You? (2026)
Choose Clue if privacy and a research-backed, no-frills design matter most; it is CE-marked as a Class 1 medical device in the EU. Choose Stardust if moon-phase and hormone-stage content is what keeps you tracking, and read its privacy record first. Veya, our app, suits people who want cycle, mood and lab tracking in one record.
Full Transparency
This comparison is published by Holland Neurotech Inc., the company behind Veya. We've included Veya as a third option where relevant. We've done our best to compare Clue and Stardust fairly based on each app's published features, pricing, and public record. If Clue or Stardust is the better fit for you, use it. How we compared: we read both App Store listings first-hand on October 16, 2026 (ratings, in-app purchase prices, version notes) and Clue's own About and privacy pages; the Stardust findings are cited from TechCrunch's report on Mozilla's research.
Quick Answer
Clue and Stardust hold close to opposite ideas of what opening a period tracker should feel like. Clue leans on documentation: a CE mark, published research partnerships and a detailed privacy policy. Stardust leans on personality, with moon-phase content and a visual style you either love or don't. Veya sits outside that split, folding cycle tracking into a broader health record. Here's how the three compare:
- If science and privacy matter most: Go with Clue. Berlin-based, CE-marked as a Class 1 medical device in the EU, with published research partnerships.
- If the tracker itself needs personality to hold your attention: Go with Stardust. Moon-phase and hormone-stage content, cycle sharing with friends.
- If a postpartum mode matters: Stardust added one in version 4.0.0 (October 2026), while Clue's listing describes modes for periods, trying to conceive, pregnancy and perimenopause.[3][4]
- If you want cycle, symptom, mood, and lab tracking in one free app: Try Veya.
Clue and Stardust rarely get compared directly, and that's part of why the comparison is useful. They're not chasing the same user. Clue was built in Berlin in 2012 around a clinical, research-backed approach to cycle prediction, and it became a CE-marked Class 1 medical device in the EU in 2023 (Clue). Stardust is run from New York and takes a design-forward, moon-phase, astrology-flavored approach to the same core job, tracking your cycle.
Both companies also handle your data very differently, and that difference showed up clearly in TechCrunch's July 2026 report on Mozilla Foundation research. We'll walk through what you get with each app, how their approaches to privacy actually compare, and a third option built around a different premise: tracking your whole health picture rather than just your cycle.
Which is better: Clue or Stardust?
Neither wins outright. Clue (4.8 stars from about 406,000 App Store ratings) is the privacy-and-documentation pick; Stardust (4.8 from about 119,000) is the personality-and-ritual pick. Annual pricing as of October 2026 is $39.99 for Clue Plus and $24.99 to $39.99 for Stardust.[3][4][5]
| Clue | Stardust | Veya | |
|---|---|---|---|
| Best for | Science and privacy | Daily ritual, astrology feel | Whole-health tracking |
| Company base | Berlin, Germany | New York, US | US-based |
| Platform | iOS + Android | iOS + Android | iOS only (+ web app) |
| Design | Clinical, minimal | Moon-phase, astrology visuals | Simple, metric-focused |
| Premium price (annual) | ~$39.99/yr | ~$24.99–$39.99/yr | ~$49.99/yr |
| Privacy record | CE-marked, GDPR | Reported sending sensitive data to an analytics firm (Jul 2026) | No ads, no data selling |
Want more detail? Keep reading.
What changed in Clue and Stardust in 2026?
Stardust shipped version 4.0.0 in October 2026 with a new Postpartum Mode, after adding Cycle Recap in version 3.7.0. Clue now ships a new version every week (298.0 as of October 2026) and its listing says Clue Plus insights can be combined with wearable temperature, sleep and heart rate data.[3][4]
- Clue: 4.8 stars from 406,000 ratings; Clue Plus is $9.99 for one month or $39.99 for one year.[3]
- Stardust: 4.8 stars from 119,000 ratings; plans listed include a $6.99 Monthly Plan and a $29.99 Annual Plan, and the listing does not say which features are free and which are paid.[4][6]
If Flo is also on your list, see Flo vs Clue vs Stardust; for Clue against a contraceptive-method app, see Clue vs Flo vs Natural Cycles.
What do you get with Clue?
Clue is a Berlin-built tracker rated 4.8 from about 406,000 App Store ratings as of October 2026, with Clue Plus at $39.99 a year.[3] Founded in 2012 by Ida Tin, Hans Raffauf, Moritz von Buttlar and Mike LaVigne, it became CE-marked as a Class 1 medical device in 2023 and lists research with Oxford University (2018) and the Kinsey Institute (2019).[1]
Features
- Cycle tracking with predictions Clue describes as clinically validated
- 200+ symptoms and experiences, including cramps, mood, energy, skin, and sleep
- Ovulation and fertile-window predictions
- An in-app article library
- Wearable sync, including Apple Watch, Oura, WHOOP, Withings, and Fitbit (some syncing may require Clue Plus, check the app for your tier)
- Clean, gender-neutral, clinical interface
Strengths
Privacy is Clue's clearest advantage. It's based in Berlin, and its privacy policy says it meets German and EU legal requirements and that sensitive health data you track is never shared with or sold to advertisers.[2]
The science-first framing has documentation behind it. Clue lists research collaborations on its About page and the app is CE-marked as a medical device in the EU.[1] If you want a tracker with that kind of paper trail, Clue offers it.
The design stays out of the way. No zodiac signs, no lunar framing. Just cycle and symptom data in a minimal interface, which a lot of people specifically want after trying trackers with more personality baked in.
Limitations
Deeper features sit behind Clue Plus. The App Store listing describes Clue Plus as adding deeper analysis, advanced predictions, and personalized insights ($39.99/year or $9.99/month, as of October 2026).[3] Some wearable syncing may also require Plus, so check the app for your tier.
No nutrition, fitness, or mood-focused tracking beyond symptoms. Clue stays centered on cycle and reproductive health. If you want meal logging, workout tracking, or a dedicated mood log alongside your cycle, that's a separate app.
No astrology or lifestyle framing, which is either a strength or a limitation depending on what keeps you opening a tracker consistently.
Pricing
Free: Cycle and symptom tracking, ovulation predictions, article library.
Clue Plus: $9.99/month or $39.99/year on the US App Store, as of October 2026. Adds deeper analysis, advanced predictions, and personalized insights. Check current pricing in-app, as it varies by region.[3]
Download: Available on iOS and Android
What do you get with Stardust?
Stardust is developed by Stardust App LLC, based in New York, and its App Store description says it never sells or shares personal health information.[4] It pairs standard period tracking with moon-phase visuals, zodiac-flavored "witch type" content, and a distinct look that's made it one of the more design-forward period apps around, with a 4.8 out of 5 rating from roughly 119,000 App Store ratings as of October 2026.[4]
Features
- Cycle, ovulation, and hormone-stage tracking with a daily readout of what a given phase can feel like
- A moon-phase wheel that lines up lunar phases with your cycle, plus zodiac and "witch type" content
- Pregnancy tracking, including a 3D and AR baby visualization feature[4]
- Symptom logging covering flow, cervical mucus, feelings, cravings, and cycle disruptors
- Wearable data from Apple Watch and Oura Ring[4]
- Friend and partner sharing for comparing cycles
Strengths
It's genuinely fun to open. Stardust is one of the few trackers people describe that way. The daily hormone narrative and moon-phase framing make cycle tracking feel less like a chore, and that's a real reason people keep using a tracker instead of abandoning it after a week.
The core experience is free. Cycle tracking, symptom logging, and the daily content are available without paying, with Stardust Plus as an optional add-on.
The feature set has grown. Pregnancy tracking and wearable sync with Apple Watch and Oura Ring are both listed as current features, which is more than some lighter astrology-flavored trackers offer.[4]
Limitations
Its privacy record is worth weighing. TechCrunch reported on July 16, 2026, drawing on Mozilla's Nothing Personal research, that Stardust was the only one of six period apps tested that sent sensitive health data to another company: birth control type, reproductive goals, birthdate and logged symptoms reached the analytics firm RudderStack.[5] Stardust said RudderStack is "contractually prohibited from selling or using it for its own purposes," and its App Store description says "We never sell or share your personal health information," so read the current policy yourself.[4][5]
If any of this rules Stardust out, our Stardust alternatives roundup covers six other trackers.
Pricing
Free: Core cycle and symptom tracking, moon-phase and hormone content.
Stardust Plus: roughly $6.99/month, or $24.99 to $39.99 a year depending on the offer, as of October 2026, with a $29.99 Annual Plan among the listed tiers. Shorter All Access plans run $2.99 to $4.99. Check current pricing in-app.[6]
Download: Available on iOS and Android
The Third Option: Veya
Clue and Stardust both approach the same job, tracking your period, from different angles: clinical science on one side, daily ritual and design on the other. Neither one tracks mood, sleep, nutrition, or lab results alongside your cycle in real depth. That's the gap Veya is built to fill: instead of being a cycle tracker with a few extras, it tracks your whole health picture, cycle included, in one place.
Where It Adds Scope
- Cycle tracking with automatic phase detection and fertility predictions
- Whole-health logging: 350+ metrics across mood, sleep, fitness, and nutrition tracked alongside your cycle
- Support for uploading lab results so they sit next to your cycle and symptom history
- 1-click logging for fast daily tracking
- Correlation insights showing how your lifestyle connects to your cycle
- No ads, no data selling
Honest Limitations
- No CE mark or clinical research partnerships like Clue's, and no moon-phase or astrology content like Stardust's.
- iOS only. There's no Android app. A web app covers other platforms, but the full experience is iPhone-only right now.
- Smaller, newer app. It doesn't have Clue's track record since 2012 or Stardust's user base.
- AI features are premium. Advanced insights require a subscription (~$9.99/month or ~$49.99/year).
Pricing
Free: Cycle, mood, sleep, fitness, and nutrition tracking. No ads.
Premium: ~$9.99/month or ~$49.99/year for AI features and advanced insights.
Download: Available on iOS App Store
How do Clue, Stardust, and Veya compare feature by feature?
The main differences are documentation and privacy (Clue), personality and daily content (Stardust), and scope beyond the cycle (Veya). Clue lists 200+ symptoms and wearable sync, Stardust adds moon-phase content and a Postpartum Mode, and Veya logs 350+ metrics. Check marks mean the feature is included, locks mean it requires a paid subscription, warning signs mean it's limited, and X marks mean it's not available.
| Feature | Clue | Stardust | Veya |
|---|---|---|---|
| Cycle tracking | ✅ | ✅ | ✅ |
| Pregnancy mode | ✅ Listed as a mode | ✅ | ✅ |
| Symptom tracking | ✅ 200+ symptoms | ⚠️ Lighter | ✅ Detailed |
| Mood / whole-health logging | ❌ | ⚠️ Basic | ✅ Mood, sleep, fitness, nutrition |
| Lab result uploads | ❌ | ❌ | ✅ |
| Moon-phase / astrology content | ❌ | ✅ Core feature | ❌ |
| Wearable integration | ⚠️ Apple Watch, Oura, WHOOP, more | ⚠️ Apple Watch, Oura | ✅ Apple Watch, Oura, Garmin |
| Medical device / regulatory status | ✅ CE-marked (EU), Class 1 | ❌ | ❌ |
| Content library | ✅ Article library | ⚠️ Daily readouts, lighter depth | ⚠️ Limited |
| Privacy practices | ✅ GDPR; no FTC or state action found in our checks | ⚠️ Reported sending sensitive data to an analytics firm, Jul 2026 | ✅ No ads, no data selling |
| Free tier quality | ⚠️ Basic, with upsell prompts | ✅ Usable core tracking | ✅ Generous, no ads |
| Price (annual) | ~$39.99/yr | ~$24.99–$39.99/yr | ~$49.99/yr |
Should You Choose Clue, Stardust, or Veya?
Neither app is right for everyone. Choose Clue if privacy and documentation matter most ($39.99/year for Clue Plus), choose Stardust if daily content keeps you tracking ($24.99 to $39.99/year) and you have read its current policy, and choose Veya for scope beyond the cycle. Honest breakdown:
Choose Clue if:
- Privacy and a documented, research-backed approach matter most to you
- You want a CE-marked app
- You prefer a clinical, no-frills design without lifestyle framing
- You're comfortable with a focused cycle tracker (no mood, nutrition, or lab tracking built in)
Choose Stardust if:
- You stopped opening other trackers because they felt like a chore
- You like moon-phase and daily hormone content more than a plain symptom log
- You want to sync cycles with friends inside the app
- You've read the current privacy policy and are comfortable with what it discloses
Choose Veya if:
- You want cycle tracking folded into whole-health logging, symptoms, mood, and lab results
- You want to see how your lifestyle habits connect to your cycle
- You want a generous free tier with no ads
- Astrology framing and clinical certifications aren't why you open a tracker
If your cycles are unpredictable and neither app's calendar-based forecast is working for you, our guide to period trackers for irregular cycles looks at what actually helps there. And if you want Flo added to the mix, Flo vs Clue vs Stardust covers all three together.
How do Clue and Stardust handle your privacy differently?
Clue has the stronger public record: it is Berlin-based under EU GDPR while Stardust was reported to have sent sensitive details to an analytics firm. Both state they do not sell health data. The factual record for each, with dates:
Clue: Berlin, GDPR, and a CE Mark
Clue is based in Berlin, Germany, and its privacy policy says its data handling meets German and EU legal requirements and that sensitive health data is never shared with or sold to advertisers.[2] (The same policy says some non-health app events go to advertising networks.) Its About page says the app became a CE-marked Class 1 medical device in the EU in 2023, a regulatory status tied to how its cycle and ovulation-prediction features are documented, not a claim that it functions as birth control. Clue's App Store listing says it should not be used as a contraceptive.[1][3]
Stardust: A Low Score From an Independent Review
Stardust's App Store description says it never sells or shares personal health information.[4] TechCrunch reported in July 2026, drawing on research from the Mozilla Foundation's Nothing Personal series, a different picture: Stardust was the only one of six period apps tested that sent sensitive health data to another company, with birthdate, birth control type, reproductive goals and symptoms reaching the analytics firm RudderStack tied to an identifier. A Stardust spokesperson said RudderStack is "contractually prohibited from selling or using it for its own purposes."[5]
Read Stardust's current privacy policy directly if this is a deciding factor for you.
Veya: Privacy-Focused, Smaller Scale
Veya doesn't run ads and doesn't sell user data. That said, it's a newer, smaller company without the years of independent privacy review that Clue or Stardust have been through, and it doesn't carry Clue's CE mark. The no-ads, no-data-selling approach is a meaningful commitment, but it hasn't faced the same level of outside scrutiny yet.
Frequently asked questions about Clue and Stardust
Is Clue or Stardust more accurate for period predictions?
Both apps use algorithm-based prediction that improves with more logged history, and neither publishes independent accuracy figures against outside data. Clue describes its predictions as built on published cycle research and clinically validated modeling. Stardust layers moon-phase and hormone-stage content on top of its own cycle predictions, but the core method is the same calendar and symptom-based approach most trackers use. For irregular cycles, expect either app's forecast to be less reliable, and lean on the patterns you log rather than the prediction itself.
Which is better for privacy, Clue or Stardust?
Clue has the stronger public privacy record. It's based in Berlin under EU GDPR law, and its privacy policy says sensitive health data is never shared with or sold to advertisers. Stardust, based in New York, states it never sells or shares personal health information, but TechCrunch reported in July 2026, on Mozilla Foundation research, that it was the only one of six period apps tested that sent sensitive details (including birth control type and specific symptoms) to another company, an analytics firm. Read each company's current privacy policy yourself before logging sensitive symptoms.
Is Clue a medical device?
Clue's About page says it became a CE-marked Class 1 medical device in the EU in 2023, and its US App Store listing lists an FDA Owner/Operator Number. That regulatory status covers how its cycle-tracking and prediction features are built and documented, not a claim that the general tracking app functions as contraception. Clue's App Store listing says it should not be used as a contraceptive.
What happened with Stardust's privacy policy in 2026?
TechCrunch reported in July 2026, on research from the Mozilla Foundation's Nothing Personal series on period trackers, that Stardust was the only one of the six apps tested that sent sensitive data to another company. The data included birthdate, birth control type, reproductive goals and symptoms, sent to the analytics firm RudderStack tied to an identifier. Stardust's public marketing states it never sells or shares personal health information, so read its current policy directly if this affects your decision.
Does Stardust or Clue have a postpartum mode?
Stardust does: its App Store listing says version 4.0.0 (October 2026) added Postpartum Mode, on top of an existing Pregnancy Mode. Clue's listing describes modes for period tracking, trying to conceive, pregnancy and perimenopause but does not list a postpartum mode. These are listing descriptions as of October 2026, not feature tests.
What's a good alternative to Clue and Stardust?
If the reason you're comparing is that neither app tracks anything outside your cycle, Veya covers different ground: mood, sleep, fitness, nutrition, and uploaded lab results sit in the same record as your cycle, with correlation insights across them. Core features are free with no ads. It's iOS only (a web app covers other platforms), it carries neither Clue's research partnerships nor Stardust's daily content, and it's newer and smaller than both.
References
- Clue (Biowink GmbH). About Clue. helloclue.com/about-clue. Fetched October 9, 2026.
- Clue (Biowink GmbH). Privacy Policy. helloclue.com/privacy. Fetched October 9, 2026.
- Clue. App Store listing. apps.apple.com/us/app/clue-period-cycle-tracker. Fetched October 16, 2026.
- Stardust (Stardust App LLC). App Store listing. apps.apple.com (Stardust Period Tracker, id1495829322). Fetched October 16, 2026.
- TechCrunch. Period tracker Stardust shares users' health data with analytics firm, says Mozilla research. techcrunch.com, July 16, 2026.
- Stardust (Stardust App LLC). In-app purchase tiers listed on the App Store. apps.apple.com (Stardust Period Tracker, id1495829322). Fetched October 16, 2026.
Facts checked first-hand against both App Store listings (October 16, 2026), Clue's own pages and the linked reporting. Prices and policies change, so confirm current details on each company's site before subscribing or logging sensitive data.
Want to See More Apps Compared?
This guide focused on Clue vs Stardust, but there's more to look at depending on why you're comparing. If Flo is also in the mix, or you want the science-vs-privacy angle taken further, these go deeper.
- Clue vs Flo: Which Period Tracker Is Actually Better? →
- Flo vs Stardust: Which Period Tracker Fits You? →
- Flo vs Clue vs Stardust: 2026 Period App Showdown →
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- Best Period Tracker App 2026: Clue vs Flo vs Ovia (6 Apps Compared)
- Best Period Tracker for Irregular Cycles
- How Accurate Are Period Tracker Apps, Really?
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- Clue vs Natural Cycles: Which One Should You Use?
- Stardust Alternatives 2026: 6 Period Trackers Compared
- Flo vs Veya: Which One Should You Use?
- Best Symptom Tracker App for Women 2026: 5 Apps Compared
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