Build scripts that cross-compile Python 3 for Android devices.

Currently targeting Python 3.13.11.

Building requires:

1. Linux (other platforms supported by NDK may work but are not tested)
2. Android NDK r19 or above. Set $ANDROID_NDK to its root directory. Tested with NDK r26.2 (26.2.11394342).
3. tic binary from ncurses on the building host (for terminfo generation)
4. A case-sensitive filesystem. The default filesystem on Windows and macOS is case-insensitive and building may fail.
5. curl, patch, make, gcc on the building host

Note: A matching-version Python on the host is not required. The build script automatically compiles a native Python of the same version from source and uses it as the cross-compilation build-python.

Running requires:

1. Android 5.0 (Lollipop, API 21) or above
2. Architecture: arm, arm64, x86, or x86_64

./clean.sh
ARCH=arm64 ANDROID_API=21 ANDROID_NDK=/path/to/ndk ./build.sh

Supported ARCH values: arm, arm64, x86, x86_64

The build proceeds in the following steps:

1. Download Python source if not already present in src/
2. Copy the Android/ build scripts into the source tree
3. Apply unversioned-libpython.patch if needed (skipped on Python 3.13+ which already includes the fix)
4. Build a native Python of the same version into native_python/ (reused on subsequent builds if already present)
5. Build Android dependencies (bzip2, gdbm, libffi, libuuid, ncurses, openssl, readline, sqlite, xz, zlib) into Android/sysroot/
6. Configure and build Python for Android
7. Install into build/
8. Remove files not needed at runtime: test/, idlelib/, config-*/, libpython*.a, and the accidental ensurepip path
9. Strip debug symbols from ELF binaries and .so files using NDK llvm-strip

Output is placed in build/. A typical build produces ~80 MB after cleanup and stripping (down from ~370 MB before).

Download the latest NDK for Linux from https://developer.android.com/ndk/downloads and extract it.

docker run --rm -it \
  -v $(pwd):/python3-android \
  -v /path/to/android-ndk:/android-ndk:ro \
  --env ARCH=arm64 \
  --env ANDROID_API=21 \
  python:3.13-slim \
  /python3-android/docker-build.sh

Podman is also supported. Simply replace docker with podman.

1. Make sure adb shell works
2. Copy all files in build/ to a folder on the device (e.g., /data/local/tmp/python3). Note that /sdcard is not a POSIX-compliant filesystem; the Python binary will not run from there.
3. In adb shell:

cd /data/local/tmp/python3
. ./env.sh
python3

Android uses the old certificate naming scheme while OpenSSL uses the new one. If you get CERTIFICATE_VERIFY_FAILED, collect system certificates:

cd /data/local/tmp/python3
mkdir -p etc/ssl
cat /system/etc/security/cacerts/* > etc/ssl/cert.pem

The certificate path may vary by device vendor and Android version. Root access is required to collect user-installed certificates.

Verify SSL/TLS:

import urllib.request
print(urllib.request.urlopen('https://httpbin.org/ip').read().decode('ascii'))

./clean.sh

This removes src/, build/, native_build/, and native_python/. To preserve the native Python build across clean cycles (saves significant build time), remove native_build and native_python from clean.sh.

• Python 3.13.11 cannot be cross-compiled using a host Python 3.13.0 binary due to an internal API change in linecache._register_code between those versions. The build script works around this by building a native Python 3.13.11 from source automatically.
• The unversioned-libpython.patch is a no-op on Python 3.13+ (the fix is already included upstream). The build script skips it gracefully.