Apk (file format)
file format used for software on Google's Android operating system
The Android Package with the file extension apk is a package format used by Android and a number of other Android-based operating systems for distribution and installation of mobile apps, mobile games and middleware. A file using this format can be built from source code written in either Java or Kotlin.
APK files can be generated and signed from Android App Bundles.
Overview
APK is analogous to other software packages such as APPX in Microsoft Windows, APP for HarmonyOS or a Debian package in Debian-based operating systems. To make an APK file, a program for Android is first compiled using a tool such as Android Studio or Visual Studio and then all of its parts are packaged into one container file. An APK file contains all of a program's code (such as .dex files), resources, assets, certificates, and manifest file. As is the case with many file formats, APK files can have any desired name but, for the system to recognize them, the .apk filename suffix may be necessary.
Most Android implementations allow users to manually install APK files (sideloading) only after they turn on an "Unknown Sources" setting that allows installation from sources other than trusted ones such as Google Play. This may be done for many reasons, such as during the development of apps, to install apps not available on the store, or to install an older version of an app in the Play Store.
In August 2025, Google announced that the "Unknown sources" toggle will be replaced with a process that involves enabling developer mode and a 24-hour pause before allowing sideloading from unverified developers.
Begin with the source’s own compact description: “Apk (file format)” is file format used for software on Google's Android operating system. The dossier treats that line as a proposition to test through file, format and used, not as a finished interpretation.
Why this record matters
The phrase “file format used for software on Google's Android operating system” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Sep 7, 2026. The linked authority identifier is Q596391. None of the 0 selected statements returned an explicit reference. The first chronological checks are 2025.
Scientific names, classifications and consensus can change while older terminology persists in catalogues and historical literature. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Apk (file format)”, its source revision and the description used here.
- Expand the search: follow Apk (file format) primary sources, Apk (file format) archive and file research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Apk (file format)”?
- Has classification or technical consensus changed since the cited source?
- Is the terminology current, historical or disputed?
Search terms from this dossier
This entry incorporates text from “Apk (file format)” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.