Education · head to head
Duolingo vs Sky Guide
Sky Guide
Education
iOS astronomy app that moved from a one-time purchase to a free-to-download, subscription-tiered model
- From
- Free
- Rated
- -
The short version
- Each has a real cost: Duolingo free tier includes ads and energy-based hearts system limiting daily practice without paying; Sky Guide it is iOS-only, unlike SkySafari which also covers Android and desktop.
- They diverge on capability: Duolingo covers 40+ languages, Sky Guide covers Light pollution forecasting.
- Prices and features above were last checked on 1 September 2026.
Where they differ
Only the attributes on which Duolingo and Sky Guide actually diverge.
Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Education).
What each one covers
Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.
Only in Duolingo
- 40+ languages
- Gamification
- Streaks
- Leaderboards
- Stories
- Podcasts
- Speaking exercises
- AI tutor
Only in Sky Guide
- Light pollution forecasting
- Meteor shower prediction
- Camera and gyroscope sky view
- Deep-sky object catalogue
- Extreme zoom
- Satellite tracking
What people use each for
The jobs each tool is most often brought in to do.
Duolingo
- Language learningnot Sky Guide
- Travel preparationnot Sky Guide
- Career developmentnot Sky Guide
- Cultural explorationnot Sky Guide
Sky Guide
- An iOS stargazer who wants light pollution forecasting to plan a dark-sky observing tripnot Duolingo
- Someone tracking meteor showers and wanting a forecast of viewing conditionsnot Duolingo
- A user who wants extreme zoom into deep-sky objects without owning a telescopenot Duolingo
- A buyer comparing subscription astronomy apps on iOS specifically, rather than cross-platform toolsnot Duolingo
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Duolingo
- Free tier includes ads and energy-based hearts system limiting daily practice without paying
- Gamification focus may appeal to casual learners but lacks depth for serious language study beyond conversational basics
- Limited to short, bite-sized lessons without extensive grammar explanations or cultural context
Sky Guide
- It is iOS-only, unlike SkySafari which also covers Android and desktop.
- It has moved from one-time purchase to a subscription model, and long-time users who paid once for earlier versions have criticised the change publicly.
- Pro tier pricing is high relative to Star Walk 2 for broadly similar core stargazing functionality.
- It has no telescope control, unlike SkySafari Plus and Pro, which limits it to naked-eye and camera-based observing.
- Its relationship to other apps under the same distribution platform is not clearly documented, which makes long-term support commitments harder to assess.
Pricing, plan by plan
Duolingo
Free- FreeFree
- All language courses
- Ad-supported
- Limited hearts (5-heart system)
- Super$12.99/month
- Ad-free
- Unlimited hearts
- Extra practice tools
- Super Family$119.99/year
- Up to 6 users
- All Super features
- Family group
- Max$undefined/mo
- All Super features
- Video Call with Lily
- Roleplay scenarios
Sky Guide
Free- Sky GuideFree
- Base sky map and object labelling
- Sky Guide Plus$19.99/year
- Larger star and satellite catalogue
- Light pollution forecasting
- Meteor shower prediction
- Sky Guide Pro$39.99/year
- Very large deep-sky object catalogue
- Exoplanet data
- Extreme zoom
Which should you pick?
Choose Duolingo if
- You need 40+ languages.
- You want to start without paying.
- You work on iOS, Android, Web.
- You also want gamification.
Choose Sky Guide if
- You need light pollution forecasting.
- You want to start without paying.
- You work on iOS.
- You also want meteor shower prediction.
Questions people ask
- Is Duolingo or Sky Guide better?
- Neither clearly leads. Duolingo starts at Free and Sky Guide at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Duolingo or Sky Guide?
- Duolingo starts at Free and Sky Guide at Free.
- Does Duolingo or Sky Guide run on more platforms?
- Duolingo runs on iOS, Android, Web. Sky Guide runs on iOS.
- Can I use Duolingo for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Duolingo best used for?
- Duolingo is most often used for language learning, travel preparation, career development, cultural exploration. Of those, language learning and travel preparation are not what Sky Guide is typically brought in for.
- What can Duolingo do that Sky Guide cannot?
- Duolingo covers 40+ languages, Gamification, Streaks, Leaderboards. Sky Guide covers Light pollution forecasting, Meteor shower prediction, Camera and gyroscope sky view, Deep-sky object catalogue.
Answered from the vendors’ own pages
Duolingo: What is Duolingo's pricing model?
Duolingo offers free tier with ads and limited features, Super Duolingo at $12.99/month (ad-free, unlimited hearts, extra practice), Super Family at ~$119.99/year for up to 6 users, and Duolingo Max with AI features like Video Call and Roleplay.
SourceSky Guide: Is Sky Guide free?
The base app is free to download; Plus and Pro are subscription upgrades for a larger catalogue and forecasting features.
Duolingo: Is Duolingo effective for language learning?
Duolingo has 135+ million monthly active users as of Q3 2025, making it the world's most widely used language-learning app. Its gamified approach and free tier have driven massive adoption.
SourceSky Guide: Did Sky Guide used to be a one-time purchase?
Yes, earlier versions were sold as a one-time purchase before it moved to the current free-plus-subscription model.
Duolingo: What AI features does Duolingo Max include?
Duolingo Max includes Video Call for conversation practice with AI character Lily and Roleplay for scenario-based speaking practice. As of January 2026, Explain My Answer became free for all users.
SourceSky Guide: Does Sky Guide support telescope control?
No. For telescope control, SkySafari Plus or Pro is the better choice.
Duolingo: Does Duolingo work offline?
Duolingo is primarily online, though it may offer limited offline lesson downloads on some platforms. Full features require internet connection.
SourceRelated pages
Other head to heads
- Duolingo vs Babbel
- Duolingo vs Busuu
- Duolingo vs Rosetta Stone
- Duolingo vs Memrise
- Duolingo vs Quizizz
- Duolingo vs Codecademy
- Duolingo vs Khan Academy
- Duolingo vs Merlin Bird ID
- Duolingo vs Seek by iNaturalist
- Duolingo vs Stellarium
- Duolingo vs Replit AI Agent
- Duolingo vs 360Learning
- Duolingo vs MasterClass
- Duolingo vs Miro Education
- Duolingo vs Panorama Education
- Duolingo vs ParentSquare
- Duolingo vs Skoolur
- Duolingo vs Veracross
- Duolingo vs SkySafari
- Duolingo vs Star Walk 2
- Duolingo vs Anki
- Duolingo vs PictureThis
- Duolingo vs Simply Piano
- Duolingo vs Yousician
- Duolingo vs Elevate
- Duolingo vs Lumosity
- Duolingo vs Photomath
- Duolingo vs Flowkey
- Duolingo vs ClassLink
- Duolingo vs Gaggle
- Duolingo vs Gimkit
- Duolingo vs Jackrabbit Class
- Duolingo vs eBird
- Sky Guide vs Babbel
- Sky Guide vs Busuu
- Sky Guide vs Rosetta Stone
- Sky Guide vs Memrise
- Sky Guide vs Quizizz
- Sky Guide vs Codecademy
- Sky Guide vs Khan Academy
- Sky Guide vs Merlin Bird ID
- Sky Guide vs Seek by iNaturalist
- Sky Guide vs Stellarium
- Sky Guide vs Replit AI Agent
- Sky Guide vs 360Learning
- Sky Guide vs MasterClass
- Sky Guide vs Miro Education
- Sky Guide vs Panorama Education
- Sky Guide vs ParentSquare
- Sky Guide vs Skoolur
- Sky Guide vs Veracross
- Sky Guide vs SkySafari
- Sky Guide vs Star Walk 2
- Sky Guide vs Anki
- Sky Guide vs PictureThis
- Sky Guide vs Simply Piano
- Sky Guide vs Yousician
- Sky Guide vs Elevate
- Sky Guide vs Lumosity
- Sky Guide vs Photomath
- Sky Guide vs Flowkey
- Sky Guide vs ClassLink
- Sky Guide vs Gaggle
- Sky Guide vs Gimkit
- Sky Guide vs Jackrabbit Class
- Sky Guide vs eBird