An APK signature is a cryptographic proof that an Android app package (.apk) was created by a known developer and has not been tampered with after signing. Android refuses to install or update an app whose signature does not match the previously installed version. Verifying a signature is the fastest way to confirm an APK's authenticity before side-loading.
META-INF/*.RSA/.DSA/.SF. Signs each file individually; theoretically exposed to a strip attack but still widely used.Modern apps are usually signed with v1+v2 or v2+v3 together. This tool detects and reports every scheme present.
Most online "APK signature checker" services ask you to upload your file to their server — a privacy and leak risk, especially for unreleased or internal builds. This viewer runs 100% in your browser: the APK is parsed on your device and never uploaded or leaves the browser. Nothing is sent to any server.
Yes. Parsing is fully local. Your APK file is never uploaded; only the generated report may be stored in your browser's localStorage for convenience.
v1 (META-INF JAR signing), v2 and v3 (APK Signing Block). The tool lists each signer with its scheme, certificate fingerprints, validity, issuer and subject.
They are one-way hashes of the signing certificate. SHA-256 is the current standard for comparing and trusting a certificate; MD5 and SHA-1 are shown for compatibility with older tooling.
No. It only reads the file to display signature information. It never installs, writes to, or alters the APK.
You can verify any .apk file you have locally — exported, side-loaded, or downloaded. The tool reads the package's own signature, independent of where it came from.