Clue vs Stardust vs Glow: Period Trackers Compared (2026)
Clue is the science-forward logger, Stardust is the astrology-flavoured daily ritual, and Glow is the community-and-TTC app. This comparison covers how each predicts your cycle, how deep the symptom logging goes, who has a community, how the privacy records differ, and what each costs, using each app's own listing and named public sources as of October 2026.
Full Transparency
This comparison is published by Holland Neurotech Inc., the company behind Veya. We've included Veya as one column among equals, with its limits stated. We compared Clue, Stardust, and Glow using each app's published features, pricing, and public record. If one of them fits you better than Veya does, use it.
Last updated: October 2026. Prices and listings were checked on October 16, 2026.
Quick Answer
- Science-forward logging: Clue. Its listing offers 200+ trackable symptoms and four modes (period, conceive, pregnancy, perimenopause).[1]
- A daily ritual with astrology and moon phases: Stardust. Its listing combines cycle tracking with a moon calendar, zodiac readings, and cycle sharing, but TechCrunch reported in July 2026 that it sent sensitive health data to an analytics firm.[2][7]
- Community and trying to conceive: Glow. Its listing predicts the fertile window and ovulation day and describes a large user community.[3]
What is the main difference between Clue, Stardust, and Glow?
The three apps start from different ideas. Clue positions itself as privacy-first and clinically minded, with a listing that cites a "clinically-validated algorithm."[1] Stardust wraps cycle tracking in lunar phases and zodiac readings.[2] Glow groups its tools around ovulation, pregnancy, and baby tracking and describes a supportive community.[4] Here is the side-by-side, with each cell traced to the app's own listing.
| Clue | Stardust | Glow | Veya | |
|---|---|---|---|---|
| Philosophy | Science-forward logging[1] | Astrology and moon-phase ritual[2] | Ovulation, TTC, community[3] | Cycle inside a wider health log[8] |
| Modes | Period, conceive, pregnancy, perimenopause[1] | Period tracking plus Pregnancy Mode[2] | Four separate apps[4] | Period, PCOS, perimenopause, pregnancy, postpartum, TTC[8] |
| Symptom logging | 200+ symptoms[1] | Symptom, mood, craving logging[2] | Fertility signs incl. cervical mucus[3] | Symptom, mood, energy, sleep, nutrition[8] |
| BBT | Wearable sync (Apple Watch, Oura, WHOOP, Withings, Fitbit)[1] | Apple Watch, Oura, or manual[2] | Yes, advanced chart in Premium[3] | Apple Health, Oura sync[8] |
| Social side | Articles (400+)[1] | Share with partners or friends[2] | Large user community[3] | No community feature |
| Paid plan | $39.99/yr, $9.99/mo[1] | $6.99/mo, $24.99 to $39.99/yr[2] | $59.99/yr after 7-day trial[4] | $49.99/yr, $9.99/mo[8] |
| App Store rating | 4.8, 406K ratings[1] | 4.8, 119K ratings[2] | 4.7, 75K ratings[3] | Not enough ratings to report |
How do the three apps predict your cycle?
All three predict periods from the dates you log, and they differ in how much they say about the method. Clue's listing describes predictions based on cycle length, flow, and patterns, plus ovulation and fertile-window predictions from a "clinically-validated algorithm."[1] Stardust's listing promises period, PMS, mood, craving, and fertility predictions.[2] Glow's listing says it predicts the fertile window and ovulation day.[3]
Stardust is the one that turns the prediction into a story. Its listing describes a day-by-day view of hormone changes alongside a moon calendar and sun, moon, and rising sign readings.[2] None of the three listings claims to be contraception, and Clue's says so explicitly.[1] If your cycles are irregular, our guide to period trackers for irregular cycles covers how calendar predictions behave, and the period calculator shows a range instead of a single date.
How deep is the symptom tracking in each app?
Clue goes widest on paper. Its listing says you can "track 200+ symptoms and experiences," including cramps, PMS, mood, sleep, and discharge, and it lets you log birth control from pills to IUDs.[1] Stardust's listing covers symptom logging with daily insights, plus sleep and activity data for cycle insights.[2] Glow's listing leans on fertility signs, including cervical mucus and BBT.[3]
Clue
Clue is the app to look at if you want to log a lot and keep the interface out of the way. It switches between period, conceive, pregnancy, and perimenopause modes, and it syncs with Apple Watch, Oura, WHOOP, Withings, and Fitbit.[1] Its listing also says the app is a regulated medical device under US law and is not for contraception.[1] The trade-off is that deeper analysis, advanced predictions, and personalized insights sit in Clue Plus.
Stardust
Stardust trades depth for atmosphere. The core logging is standard (symptoms, mood, cravings, BBT through a wearable or by hand), and the extras are lunar syncing, zodiac content, and sharing with partners or close friends.[2] Its 4.8 rating across about 119K ratings suggests the tone works for a lot of people.[2]
Glow
Glow splits its tools into an Ovulation Tracker, a Pregnancy Tracker, a Baby Tracker, and a Period Tracker called Eve.[4] The Ovulation Tracker is the one aimed at people trying to conceive, and the listing includes BBT with an advanced chart in Premium. The listing does not mention LH test logging, so check inside the app if that matters to you. For mucus-specific logging, see our guide to apps that track cervical mucus.
Which app has community or social features?
Glow and Stardust both have a social side and Clue mostly does not. Glow's listing describes a large user community, and its site talks about a supportive community of women across the Glow apps.[3][4] Stardust lets you share your cycle with invited partners or close friends.[2] Clue's listing describes 400+ educational articles on cycles, fertility, pregnancy, and perimenopause instead.[1]
If anonymous peer chat is the draw, Flo's Secret Chats are the closest match, and we compare that app in Flo vs Clue vs Glow and Flo vs Glow.
How do the apps differ in design?
Design is taste, so here is only what the listings describe. Stardust leans visual, with a moon calendar, zodiac readings, and 3D and AR baby-size views in Pregnancy Mode.[2] Clue's listing frames the app around privacy and clinical credibility rather than decoration.[1] Glow's listing emphasizes fertility charting, including an advanced BBT chart in Premium.[3] Open each for a day before paying, since the free downloads make that easy.
What do Clue, Stardust, and Glow say about privacy?
The records differ a lot. We found no enforcement action or reported data incident for Clue, Glow settled with California's Attorney General in 2020 and had a profile-data bug in 2024, and reporting in 2022 and 2026 challenged Stardust's encryption and data-sharing claims. The dated facts are below, so read each app's current policy before logging.
Stardust and the end-to-end encryption claim. In 2022 Stardust said it was end-to-end encrypted, and TechCrunch's network analysis found the claim was false.[6][7] The founder described standard SSL traffic to AWS with AES-256 for stored data, and Stardust removed the end-to-end encryption mentions from its policy after TechCrunch got in touch.[6] Its site tagline, per TechCrunch's 2026 report, is "Your data is private. Period."[7] That report, drawing on Mozilla's research, said Stardust sent birthdate, birth control type, reproductive goals, and symptoms to 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."[7] Its App Store privacy label lists health data as "not linked to you" and identifiers as used to track you.[2]
Clue. The listing markets Clue as privacy-first and GDPR-protected, and the company is based in Berlin.[1] The same listing's privacy label still lists health data as linked to you, which is normal for an app that stores your logs on a server.[1]
Glow. Glow's policy, effective October 12, 2026, says "We do not sell or share health information from our users." It also says it may share names, email addresses, and device identifiers with advertising partners, and it offers an Offline Data Protection option that keeps key health data on your device.[5] The record includes a $250,000 settlement with California's Attorney General in September 2020 and a February 2024 bug that exposed profile data (not health logs) for around 25 million users, per TechCrunch.[9][10]
What does each app cost in October 2026?
All three are free to download with in-app purchases. Clue Plus is $39.99 a year or $9.99 a month.[1] Stardust lists a $6.99 monthly plan and annual plans from $24.99 to $39.99, including a $29.99 Annual Plan.[2] Glow Premium is $59.99 a year after a 7-day free trial on its site, with the App Store listing showing Premium purchases from $15.99 to $69.99.[3][4]
The free tiers are less clear. Clue's listing says Clue Plus adds the deeper analysis, so basic tracking is free.[1] Stardust and Glow do not itemize their free features, so check what you can do before the paywall appears.[2][4]
Where does Veya fit?
Veya sits in a different spot from all three: cycle tracking alongside symptoms, mood, energy, sleep, and nutrition in one log, with Apple Health, Apple Watch, and Oura integration.[8] Pro is listed at $49.99 a year or $9.99 a month.[8] The limits are real. Veya is iOS only (with a web app), has no community feature, and it is newer, with far less track record than Clue, Stardust, or Glow.[8] If you track mood alongside your cycle, our mood tracking app comparison covers more options.
Which app should you choose?
Pick by the reason you open a tracker, not by a winner.
Choose Clue if you want to log a lot:
- You want 200+ symptoms and separate modes for each life stage
- Privacy matters to you and you want the app with no reported third-party sharing incident in our checks
- You're fine with deeper analysis sitting behind Clue Plus
Choose Stardust if the ritual is the point:
- You enjoy moon phases, zodiac readings, and daily hormone explanations
- You want to share your cycle with a partner or friends
- You've read its current privacy policy and are comfortable with it
Choose Glow if ovulation and community lead:
- You're trying to conceive and want fertility charting with BBT
- You like having separate pregnancy and baby apps for later
- You're comfortable with its advertising-partner sharing described in the policy
Choose Veya if you want cycle data next to everything else you log:
- You track sleep, mood, or nutrition and want to compare them alongside your cycle
- You use an iPhone and don't need a community
Want head-to-heads instead? See Clue vs Stardust, Flo vs Stardust, Flo vs Clue vs Stardust, Flo vs Clue vs Glow, and Flo vs Glow.
How we compared these apps
We read the current US App Store listings for Clue, Stardust, Glow, and Veya on October 16, 2026, along with Glow's apps and Premium page and Glow's privacy policy (effective October 12, 2026), and recorded features, in-app purchase prices, ratings, and privacy-label categories as listed. Stardust's privacy history comes from TechCrunch's original network analysis and reporting. Where a listing or site did not say something, we say so instead of guessing. Prices shift with promotions and regions. Veya is made by the company that publishes this page.
Frequently Asked Questions
Which is better, Clue, Stardust, or Glow?
It depends on what you want from a tracker. Clue lists 200+ symptoms and four modes in its App Store listing, Stardust adds moon-phase and zodiac content to standard tracking, and Glow centres on ovulation tracking with a large user community. None of them is the right pick for everyone, so match the app to your reason for tracking.
Is Stardust really end-to-end encrypted?
In 2022 Stardust said it was end-to-end encrypted, and TechCrunch's network analysis found the claim to be false. After TechCrunch got in touch, Stardust removed the end-to-end encryption mentions from its privacy policy. Its App Store listing today describes data as protected and never sold or shared, with no mention of encryption.
Is Glow free?
Glow's four apps are free to download, and its site names Premium extras such as the GlowGPT assistant, advanced analytics, and ad-free use. Premium is listed at $59.99 a year after a 7-day free trial on Glow's site (as of October 2026). The App Store listing shows Premium purchases from $15.99 to $69.99.
How much does Clue Plus cost?
Clue Plus is listed at $39.99 a year or $9.99 a month on the US App Store (as of October 2026). Clue is free to download with in-app purchases, and Clue Plus adds deeper analysis, advanced predictions, and personalized insights.
Which of these three has the best privacy record?
Of the three, Clue has no enforcement action or reported data incident in our checks. Glow paid $250,000 to California's Attorney General in 2020 over consent and account-verification flaws, and TechCrunch reported in July 2026 that Stardust sent sensitive health data to an analytics firm. See the privacy section above for the dated record on each.
Which period tracker is best if I want a community?
Glow's listing describes a large user community, and Stardust lets you share your cycle with invited partners or close friends. Clue's listing describes educational articles rather than a community. Flo, which is not in this comparison, runs the Secret Chats community, and we compare it in Flo vs Clue vs Glow.
References
- Clue (BioWink GmbH). App Store listing: modes, 200+ symptoms, Clue Plus pricing, ratings, privacy label. apps.apple.com. Fetched October 16, 2026.
- Stardust App LLC. Stardust Period Tracker App Store listing: features, plans, ratings, privacy label. apps.apple.com. Fetched October 16, 2026.
- Glow, Inc. Glow Ovulation & Period App, App Store listing: features, in-app purchases, ratings, privacy label. apps.apple.com. Fetched October 16, 2026.
- Glow, Inc. Glow apps and Premium. glowing.com/glow. Fetched October 16, 2026.
- Glow, Inc. Privacy Policy (effective October 12, 2026). glowing.com/privacy. Fetched October 16, 2026.
- TechCrunch. Stardust period tracker phone number and encryption reporting. techcrunch.com, June 27, 2022.
- TechCrunch. Period tracker Stardust shares users' health data with analytics firm, says Mozilla research. techcrunch.com, July 16, 2026.
- Holland Neurotech Inc. Veya App Store listing. apps.apple.com. Fetched October 16, 2026.
- California Attorney General. Attorney General Becerra Announces Landmark Settlement Against Glow, Inc. oag.ca.gov, September 17, 2020.
- TechCrunch. Fertility tracker Glow fixes bug that exposed users' personal data. techcrunch.com, February 13, 2024.
Facts checked against official pages and named sources, October 2026. Prices and policies change, so confirm current terms on each company's site before subscribing.
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Still deciding between the three above? Track one cycle in whichever app fits your situation and see how it feels.