Scarlet vs AltStore: Key Differences Explained
Scarlet and AltStore are the two names almost everyone lands on when they first look into sideloading without a jailbreak — and they could hardly solve the problem more differently. AltStore signs apps with your own free Apple ID from a computer on your Wi-Fi. Scarlet installs directly on the iPhone using enterprise certificates. Both are legitimate, both are free, and each one’s biggest strength is the other one’s biggest weakness. This comparison lays out the differences that actually affect daily use, so you can pick based on your habits instead of hype.
How Each One Works
AltStore is a two-part system: AltServer runs on your Windows PC or Mac, and AltStore lives on your iPhone. When you install an app, AltServer uses your Apple ID to create a personal development certificate and signs the app just for your devices. Because it rides on Apple’s free provisioning system, the apps expire after 7 days — AltStore refreshes them in the background whenever your phone and computer share a Wi-Fi network, which is why the computer is a permanent part of the arrangement. A free Apple ID can sign a limited number of apps at once (three, including AltStore itself in practice) and a limited number per week.
Scarlet skips the computer entirely. It installs on-device using an enterprise certificate — by default a shared one that comes with it — and signed apps carry that certificate’s expiry, which is measured in months rather than days. The trade is that enterprise certificates can be revoked by Apple at any moment, and when Scarlet’s shared certificate is revoked, everything signed with it stops until it is replaced. Our certificate status hub explains that cycle; it is the defining fact of Scarlet ownership.
Scarlet vs AltStore at a Glance
| Scarlet | AltStore | |
|---|---|---|
| Computer required | No — fully on-device | Yes — AltServer on PC/Mac, same Wi-Fi for installs and refreshes |
| What signs your apps | Enterprise certificate (shared by default; your own can be imported) | Your own Apple ID (free provisioning) |
| How long apps last | Until the certificate expires or is revoked — unpredictable, often months | 7 days per signing, auto-refreshed in the background when set up well |
| App limits | No Apple-imposed count; limited by the certificate | Small hard limits on active apps and weekly signings with a free Apple ID |
| Failure mode | Sudden and total: a revoke stops everything at once | Gradual: a missed refresh lets apps expire one by one |
| App library | Built-in repos for browsing and updating apps | Minimal built-in sources; you mostly supply your own IPAs |
| Setup difficulty | Low — install, trust the profile, done | Moderate — computer setup, Mail/iTunes dependencies on Windows, refresh habits |
| Cost | Free | Free (a paid developer account removes the 7-day cycle if used with it) |
The Daily-Use Difference
AltStore, once configured, is boring in the best way: keep your computer on the same network reasonably often and your apps quietly stay alive. Its users think in routines. Scarlet is effortless until it isn’t: weeks of zero maintenance, then a revoke morning where nothing opens and you reinstall with the fresh certificate. Which failure style you prefer is honestly the core of this choice. People also underestimate AltStore’s app ceiling — if your sideloading habit is “a couple of essential apps,” the free provisioning limits never bite; if you like trying a new tweaked app every week, you will hit them constantly, while Scarlet’s repo system (see our best Scarlet repos guide) is built for exactly that browsing habit.
What About Safety and Your Apple ID?
AltStore asks for your Apple ID credentials in AltServer to request certificates from Apple. It is a long-standing, well-regarded open-source project, and the credentials are used to talk to Apple’s signing servers — but you should still understand what you are handing over, and many users create a secondary Apple ID for the purpose. Scarlet never asks for your Apple ID at all; its trust question is different — you are trusting an enterprise certificate run by someone else, unless you import your own as described in our certificate import guide. Neither approach is “the safe one” in absolute terms; they place trust in different places.
Which Should You Choose?
- You hate computers being involved and want apps now: Scarlet.
- You keep only 1–3 essential sideloaded apps and value predictability: AltStore, especially if your PC is always on the same network.
- You browse repos and install lots of apps: Scarlet — AltStore’s free limits will frustrate you daily.
- Revoke mornings would genuinely upset you: AltStore’s 7-day rhythm is annoying but never catastrophic.
- You are comparing the wider field: Our ESign vs Scarlet comparison and the Feather vs Scarlet comparison cover the certificate-signer branch of the family tree.
Plenty of experienced sideloaders run both: AltStore (or a sibling) babysitting one or two critical apps with their own Apple ID, Scarlet handling everything exploratory. The tools are not rivals in your pocket, only in articles like this one.
A Note on the Wider Family
AltStore also has a well-known sibling, SideStore, which removes the always-on-computer requirement by refreshing apps through a special VPN profile on the device itself — worth knowing about if AltStore’s model appeals to you but the tethered computer does not. And AltStore’s own ecosystem has regional wrinkles (its alternative-marketplaces edition exists for the EU’s app marketplace rules) that do not change the core comparison above. The honest summary of the whole field is that no method dominates: enterprise signing (Scarlet), Apple ID signing (AltStore/SideStore) and own-certificate signing (Feather, Ksign, GBox) are three different bargains with Apple’s rules, and experienced users pick per app, not per ideology.
FAQ
Is AltStore safer than Scarlet?
They carry different risks rather than different amounts of risk. AltStore uses your own Apple ID and Apple’s own free provisioning, so there is no third-party certificate to be revoked — but you enter Apple ID credentials into a computer program. Scarlet needs no Apple ID, but its shared certificate can be revoked without warning.
Why do AltStore apps expire every 7 days?
Because AltStore signs with a free Apple ID’s personal provisioning, which Apple limits to 7-day certificates. AltStore refreshes the apps automatically over Wi-Fi before they expire, so in a well-kept setup you rarely notice — miss the refresh window and the app stops opening until it is refreshed again.
Can AltStore install as many apps as Scarlet?
No. Free Apple ID signing has small limits on how many apps can be active and signed per week, which AltStore cannot bypass. Scarlet, signing with an enterprise certificate, has no equivalent Apple-imposed app count.
Do I need a computer for Scarlet?
No. Scarlet installs and runs entirely on the iPhone. A computer-based install method also exists as an option, but it is not required — that is the main practical difference from AltStore, where the computer is mandatory.
Can I switch from AltStore to Scarlet (or back)?
Yes, and many people run both side by side. Your sideloaded apps are tied to however they were signed, so switching installers usually means reinstalling the apps under the new method — your in-app data may or may not carry over depending on the app, so back up anything that matters first.
