Education · head to head
Anki vs Sky Guide
Anki
Education
Free open source spaced repetition flashcard app, free everywhere except iOS where it is a paid one-time purchase
- From
- Free
- Rated
- -
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: Anki the interface is functional rather than polished, and new users often find the initial setup, deck creation and add-on ecosystem confusing compared with a guided app like Memrise.; Sky Guide it is iOS-only, unlike SkySafari which also covers Android and desktop.
- They diverge on capability: Anki covers Spaced repetition scheduling, 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 Anki 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 Anki
- Spaced repetition scheduling
- Cross-platform sync
- Shared deck library
- Custom card types
- Add-ons
- Open file format
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.
Anki
- A medical student using a large shared deck to memorise anatomy or pharmacology facts on a fixed exam timelinenot Sky Guide
- A language learner building custom vocabulary decks with audio and images tailored to their own study materialnot Sky Guide
- A self-directed learner who wants full control over the scheduling algorithm and does not want a subscriptionnot Sky Guide
- An iPhone-only user deciding whether the one-time AnkiMobile price is worth it versus using the free web interface insteadnot Sky Guide
Sky Guide
- An iOS stargazer who wants light pollution forecasting to plan a dark-sky observing tripnot Anki
- Someone tracking meteor showers and wanting a forecast of viewing conditionsnot Anki
- A user who wants extreme zoom into deep-sky objects without owning a telescopenot Anki
- A buyer comparing subscription astronomy apps on iOS specifically, rather than cross-platform toolsnot Anki
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Anki
- The interface is functional rather than polished, and new users often find the initial setup, deck creation and add-on ecosystem confusing compared with a guided app like Memrise.
- iOS users pay a one-time fee of around $24.99 to $29.99 for AnkiMobile while every other platform is free, which is an unusual asymmetry that surprises new users comparing app store prices before they understand it funds development.
- Anki has no content of its own; a new user gets an empty deck and either has to build cards manually or trust the quality of a community-shared deck of unknown accuracy.
- The default scheduling algorithm requires understanding concepts like ease factor and interval to tune effectively, and default settings are not optimal for every subject or workload.
- Shared decks, especially large medical school decks, can carry factual errors or become outdated, and there is no editorial review process verifying their accuracy.
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
Anki
Free- AnkiFree
- Desktop apps for Windows, Mac and Linux are free and open source
- AnkiDroid on Android is free and open source, built by a separate volunteer team
- AnkiMobile on iOS is a one-time purchase, commonly $24.99 to $29.99, funding development
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 Anki if
- You need spaced repetition scheduling.
- You want to start without paying.
- You work on Windows, Mac, Linux, iOS, Android, Web.
- You also want cross-platform sync.
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 Anki or Sky Guide better?
- Neither clearly leads. Anki 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, Anki or Sky Guide?
- Anki starts at Free and Sky Guide at Free.
- Does Anki or Sky Guide run on more platforms?
- Anki runs on Windows, Mac, Linux, iOS, Android, Web. Sky Guide runs on iOS.
- Can I use Anki for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Anki best used for?
- Anki is most often used for a medical student using a large shared deck to memorise anatomy or pharmacology facts on a fixed exam timeline, a language learner building custom vocabulary decks with audio and images tailored to their own study material, a self-directed learner who wants full control over the scheduling algorithm and does not want a subscription, an iphone-only user deciding whether the one-time ankimobile price is worth it versus using the free web interface instead. Of those, a medical student using a large shared deck to memorise anatomy or pharmacology facts on a fixed exam timeline and a language learner building custom vocabulary decks with audio and images tailored to their own study material are not what Sky Guide is typically brought in for.
- What can Anki do that Sky Guide cannot?
- Anki covers Spaced repetition scheduling, Cross-platform sync, Shared deck library, Custom card types. Sky Guide covers Light pollution forecasting, Meteor shower prediction, Camera and gyroscope sky view, Deep-sky object catalogue.
Answered from the vendors’ own pages
Anki: Why is the iOS app not free when everything else is?
AnkiMobile is a paid one-time purchase, commonly around $24.99 to $29.99, that the developer states directly funds ongoing development of the free desktop apps, AnkiWeb sync and infrastructure used by every platform.
Sky 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.
Anki: Is Anki really free on Android?
Yes. AnkiDroid, the Android app, is free and open source, built and maintained by a separate volunteer development team from the desktop project.
Sky 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.
Anki: Do I need to pay for sync?
No. AnkiWeb, used to sync decks and review history across devices, is free.
Sky Guide: Does Sky Guide support telescope control?
No. For telescope control, SkySafari Plus or Pro is the better choice.
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