Three Version Numbers to Check Before You Sideload Anything
The most common sideload failure isn’t a bad APK. It’s a phone that’s too old for the build. You tap install and get “App not installed” or “There was a problem parsing the package”, and nothing tells you the actual reason: the app needs a newer Android than you have.
Your phone’s About phone screen has the answer, buried among IMEIs, model numbers and legal text. Only three lines matter before you install anything from outside the Play Store, whether that’s a Byteslip APK, Termux, or a build off GitHub. This page shows where they live and what each one is telling you.
What Each Number Actually Tells You
- Android version (e.g. 13, 14, 15): the big one. APKs declare a minimum version (developers call it
minSdk, an API level: Android 13 = API 33, 14 = API 34, 15 = API 35). Below that number, the install fails, full stop. Termux from F‑Droid, for example, needs Android 7 or newer. - Android security update (a date, like “1 March 2026”): the monthly patch level. It doesn’t decide whether an app installs, but it does decide how exposed you are while you’re installing apps from outside the store. If it’s more than a few months old, update before you sideload, not after.
- Google Play system update (also a date): Google’s Project Mainline modules, the under‑the‑hood pieces like media codecs and networking that update outside the big OS releases. When a video won’t play in one app but works in another, or networking acts weird, this is worth checking.
Ignore for now: kernel version, baseband, “One UI version” trivia and the rest of the About screen. They matter for flashing and bug reports, not for “will this APK run on my phone”. The Build number is worth noting for one reason: it’s what you tap seven times to unlock Developer options.
What You Need
- Wi‑Fi and roughly 75% battery or more before you download a big update (Android Help tip).
- Realistic expectations: older phones eventually stop getting new Android versions (Google). Security patches may still arrive for a while after that.
- The APK’s release notes or README open in another tab, so you can compare its minimum Android version against yours.
Read the Numbers, Then Update
Step 1: Pixel: About phone → Android version
Settings > About phone > Android version. Write down:
- Android version
- Android security update
- Google Play system update
- Build number (useful when you report a bug)
Step 2: Pixel: Check for updates
OS / software: Settings > System > Software updates (or System update) → follow the on‑screen steps. Security & Play system: Settings > Security & privacy > System & updates → Security update and Google Play system update (Android Help).
Pixel installs a lot of this in the background. The update often isn’t active until you restart, so if the date didn’t change, reboot and check again.
Step 3: Samsung: Software information
Settings > About phone > Software information. That’s Android version, security patch level, build and related fields, all on one screen. Tap Google Play system update and follow the prompts if an update is offered (Samsung).
Step 4: Samsung: Software / security updates
Settings > Software update or System updates → Download and install / Check for updates. Also: Security and privacy → Updates → Security update or Google Play system update (Samsung Security help).
The Sideload Pre‑Flight
- Android version ≥ the APK’s minimum? If not, stop. No setting will fix it, so look for an older release of the app that supports your version.
- Security patch recent? If it’s many months old and an update is waiting, install it first. Then sideload.
- Know where the APK is coming from. The developer’s own site, GitHub releases or F‑Droid. Not a re‑upload mirror. For Termux, use the F‑Droid build, which is the one most guides, mine included, assume you have.
- Allow exactly one installer. Grant “install unknown apps” to the browser or file manager you’re using, and only that one. The Install Unknown Apps guide walks through it.
Three Clocks, Three Schedules
Official docs
Android / Pixel check & update: 7680439 (also Pixel Help same ID). Samsung update / Software information: ANS10002027; Play system update path: TSG10005233; Security updates menu: ANS10002544.