Flo vs Luna vs Clue: honest comparison + Flo alternative in 2026

Flo, Luna, and Clue each take a different approach to cycle tracking.

Pattern Snapshot

The fastest way to read this comparison

Flo

Better fit if you want a polished mainstream tracker with familiar prediction habits.

Luna

Better fit if you want calmer interpretation, pattern context, and stronger privacy guardrails.

Clue

Better fit if you want EU-hosted privacy and a clean tracker without AI or partner features.

Decision

The real trade-off is product philosophy: mainstream convenience, privacy with guidance, or privacy without extras.

The right choice depends less on brand size and more on what you want the tracker to help you do every day.

Side by side

	Flo	Luna	Clue
Monetization	Freemium with ads + premium tier	Paid only (1-month free trial, then €4.99/mo)	Freemium, no ads (paid premium)
Data hosting	US	EU (Frankfurt)	EU (Berlin)
Data sold or shared	Subject of 2025 Meta verdict; practices updated since	Never	Never
AI assistant	Limited insights	Cycle-aware chat that answers from your logs	No
Partner feature	Basic, view-only	Privacy-filtered partner mode with proactive guidance	No
Predictions	One date (28-day model by default)	Ranges with confidence levels (learns your cycle)	Averages-based calendar
Same-sex couples	Not designed for it	Partner mode works regardless of partner gender	Gender-neutral by design
Account deletion	Multi-step	One tap	Standard
Languages	20+	FR, EN	Multiple
iOS / Android	Both	iOS first (Android in prep)	Both

Key differences

Flo:

• ad-based model
• large-scale data use
• broader feature set

Luna:

• subscription-based
• no data selling
• AI guidance and partner mode built in

Clue:

• freemium, no ads
• EU-hosted, no data selling
• clean tracker without AI or partner features

The differences are not just about features. They reflect three different product philosophies.

Short answer

All three apps can be useful. They solve different problems.

Flo is the mainstream option: polished, feature-rich, prediction-first, with a large user base.

Clue is the privacy-serious free option: EU-hosted, no ads, clean design, no extras.

Luna is the privacy-first option with an interpretation layer: EU-hosted, no ads, plus AI guidance and partner mode.

The right choice depends on what you want the app to actually do for you each day.

What Flo does well

Flo is easy to understand quickly.

It has the kind of onboarding and interface many people expect from a large consumer app:

• polished UX
• clear logging flows
• a familiar prediction-first experience
• a large mainstream user base
• a broad feature set

That matters because many people do not want to learn a whole new philosophy just to start tracking a cycle. They want something accessible, smooth, and recognizable.

If your main goal is straightforward tracking with a polished product feel, Flo makes sense as a serious option to consider.

Where Flo can feel limiting

For some people, mainstream convenience is exactly the point.

For others, it can start to feel a bit heavy.

The limitation is usually not one single feature. It is more about emphasis:

• more focus on prediction than interpretation
• a feature-rich experience that can feel crowded if you want clarity
• less room for the slower question of what your patterns actually mean in daily life
• a level of data uncertainty that some privacy-conscious users want to understand better

That does not make Flo a bad product. It just means that some users eventually realize they want a tracker that feels simpler in philosophy, not just in interface.

If you're comparing privacy across apps: best private period tracking apps.

To understand how apps use data: do period apps sell your data.

What Clue does well

Clue is one of the most privacy-serious apps in mainstream cycle tracking.

It is EU-based (Berlin), does not sell data, does not use advertising, and has made privacy part of its product identity from early on. The interface is clean. Its gender-neutral approach, avoiding assumptions about who uses the app or who their partner is, was ahead of most competitors.

If you want a free or low-cost tracker with solid EU privacy credentials and no ads anywhere in the product, Clue delivers that without compromise.

It also has a well-established user base, good scientific backing, and a clear design language.

How Clue differs from Luna

The clearest differences are what Clue does not include.

Clue does not have an AI assistant. There is no cycle-aware chat that reads your logs and answers questions from your own patterns.

Clue does not have a partner mode. There is no built-in way to share relevant cycle context with someone close to you while keeping private data private.

Clue's predictions are averages-based. It tracks your history and projects from that, but without the confidence ranges or uncertainty signals that Luna shows when your cycle varies.

That is not a criticism of Clue. It is a different product philosophy: Clue is a private, clean tracker. Luna is a private tracker with an interpretation and support layer on top.

If privacy and gender-neutral design are your main criteria and you do not need AI or partner features, Clue is a strong option. If you want those features with the same privacy posture, that is where Luna adds something Clue does not offer.

What changed for Flo in 2025

In August 2025, a US jury reached a verdict in a class action against Flo and Meta, confirming that Flo had shared sensitive health data — including period and pregnancy tracking — with Facebook between 2016 and 2019.

Flo settled an earlier FTC case in 2021 (which it called a "misunderstanding") and has updated its data practices since.

The verdict matters for two reasons:

1. It confirms that period-tracking data has been part of an advertising ecosystem.
2. It made many users — including longtime Flo users — start looking for alternatives where ads and tracking aren't part of the business model in the first place.

That's the gap Luna is built for. Not because Flo is unfixable. But because some users want a tracker that doesn't need fixing.

What Luna actually does differently

Three things matter most.

1. AI that speaks your cycle, not an average

When you ask "why am I more tired this week?", Luna answers based on your own logs — what you've recorded, what your patterns show — not a generic "follicular phase" template. After 4–6 weeks of tracking, the answers get specific to you.

2. Partner mode that doesn't leak

Your partner sees enough context to be helpful — where you are in your cycle, what tends to help — but never your notes, your intimacy log, or your raw symptom data. It's designed for support, not surveillance. And it works for couples of any gender.

3. Ranges, not fake precision

Luna shows your fertile window as a range with a confidence level that improves as it learns your patterns. If your cycle varies, Luna says so. If it's still learning, it tells you. No invented dates.

4. EU hosting, no ads, no data selling

Hosted in Frankfurt. No ads. No data sold to third parties. Account deletion in one tap. Not a fix to a previous practice — a starting decision.

If that is the part you care about most, understanding cycle phases through real symptoms and plan your week based on your cycle show the kind of real-life use Luna is designed around.

Pricing & access

	Flo	Luna
Free tier	Yes (with ads)	No
Trial	7-day Premium trial	1-month free trial
Premium price	~$9.99/month	€4.99/month
Cancel anytime	Yes	Yes
Refund window	Apple's standard	Apple's standard

Luna is paid because it isn't supported by ads. That's a deliberate choice — a tracker can either monetize your data or charge you a subscription, and Luna chose the latter.

Which app is better depending on what you want

If you want simple tracking and predictions

→ Flo

If you want to understand your cycle patterns

→ Luna

If privacy is a top concern and you want a free option

→ Clue

If privacy is a top concern and you want AI guidance and partner mode

→ Luna

If you want a widely used, feature-rich app

→ Flo

If you want calmer guidance instead of a more mainstream tracking ecosystem

→ Luna or Clue, depending on whether you need AI and partner features

If you want the privacy side compared more broadly, best private period tracking apps is the next useful read.

How to choose

Use this decision framework:

1. Do you want prediction or understanding?

If your main goal is seeing forecasts and keeping tracking easy, a mainstream app may feel enough.

If you want more help interpreting symptoms, energy, and timing together, Luna is better aligned.

2. Do you care how your data is handled?

If privacy is a background issue for you, the trade-off may feel less important.

If it is a top concern, it probably should shape your choice directly rather than staying an afterthought.

3. Do you want daily interpretation or mostly logging?

Some people mostly want a record.

Others want the app to help them make sense of recurring patterns without sounding dramatic or overly certain.

4. Do you prefer feature density or product restraint?

Some people like a richer, more mainstream app environment.

Others want something that feels more focused and explicit about boundaries.

5. What do you want the app to help you do in real life?

A concrete example:

If you mostly want to know when your next period may arrive, Flo may feel like the more familiar tool.

If you want to notice that your sleep gets worse before your period, your social energy drops in the same stretch, and your planning works better when you account for that pattern, Luna is the better fit.

The useful takeaway

Flo, Luna, and Clue are not trying to be the same product.

Flo makes more sense if you want a polished mainstream tracker with a broad feature set and a familiar prediction-first experience.

Clue makes more sense if you want EU-hosted privacy, no ads, and a clean tracker without AI or partner features, ideally for free.

Luna makes more sense if you want EU-hosted privacy with an interpretation layer: a cycle-aware AI and a partner mode that keeps private data private.

If you are looking for a cycle tracker that helps you understand patterns across your month, without treating your data as an afterthought, both Luna and Clue are built with that in mind. The question is whether you want guidance and partner support on top of that.

Is This Normal?

Is a mainstream period app automatically the wrong choice if privacy matters to you?

Not automatically, but the trade-offs should be visible. What matters is how clearly the app handles data collection, sharing, deletion, and prediction claims.

A familiar brand or polished product experience is not the same thing as strong privacy boundaries.

Frequently asked questions

Is Luna a real alternative to Flo?

Yes — Luna covers the same core tracking needs (period, symptoms, phases) and adds AI guidance, partner mode, and EU-only hosting. It is a paid app (€4.99 per month after a 1-month free trial), where Flo is freemium with ad-based monetization.

Is Flo still safe to use after the Meta lawsuit?

Flo updated its data practices after the 2025 verdict, but the case confirmed that sensitive cycle data was shared with Meta for years. If privacy is a top concern, an EU-hosted, ad-free app like Luna or Clue is a different posture by design — not a remediated one.

What does Luna do that Flo does not?

Three things: a cycle-aware AI chat that builds answers from your own logs, a privacy-filtered partner mode (your partner never sees your notes or temperature), and uncertainty ranges instead of fake precision dates.

How does Luna compare to Clue?

Both are EU-hosted and do not sell data. The difference is what they offer on top: Clue is a clean tracker with no AI and no partner mode, available for free. Luna adds a cycle-aware AI chat and a privacy-filtered partner mode, for €4.99 per month after a 1-month free trial. If you mainly want private tracking, Clue works well. If you want guidance and partner support on top, that is what Luna adds.

Is Luna free?

Luna offers a 1-month free trial, then €4.99 per month. There is no free tier with ads — that is a deliberate choice to keep your data outside any advertising market.

Does Luna work for same-sex couples?

Yes. Luna partner mode is gender-neutral by design. Either person in the couple can be the primary tracker or the partner.

Related reading

• How private should a period tracker be?
• Privacy-first period tracker vs ad-supported app
• Understanding cycle phases through real symptoms
• Why period apps get irregular cycles wrong
• App analytics vs sensitive health data
• How partner sharing should work in an app

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If you've been looking for a Flo alternative because privacy or generic predictions weren't working, Luna is built for that. 1 month free, €4.99/month after, cancel any time. EU-hosted.

→ Download Luna on the App Store