OTB to APK Converter
Processing entirely on your device — large files may take a moment.
OTB is the Nokia OTA Bitmap — 1-bit monochrome images that old Nokia phones displayed as operator logos and picture messages. Repack an APK as ZIP to inspect its manifest and assets (not for reinstalling).
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How to convert OTB to APK
- 1
Select your files
Select your OTB file — it never leaves your device.
- 2
Convert instantly
The engine packs the file, byte for byte, into a APK container — no re-encoding, no quality change.
- 3
Download results
Download the finished APK archive.
About the OTB format
The Nokia OTA Bitmap coder of the ImageMagick set — the retro-phone format is written natively by the magick.wasm engine, entirely in your browser.
Obscure coder formats like this are exactly what template-driven converters list and never actually convert — here it really works.
+Strengths
- ✓Written natively by ImageMagick
- ✓Runs entirely in your browser
- ✓Free, private, no watermarks
!Limitations
- −Niche format — few modern readers
- −Feature subset varies by coder
- −Keep the original for re-editing
About the APK format
An APK is Android’s install package: a ZIP holding AndroidManifest.xml, compiled DEX bytecode, native libraries and assets. Unpacking one is the standard first step of security review, compatibility checks and asset recovery.
One honest limit: unpacking is inspection, not installation — a repacked ZIP cannot be installed back onto a phone, and the page says so.
+Strengths
- ✓Everything an Android app ships
- ✓ZIP-based, easy to unpack
- ✓Manifest readable as XML
!Limitations
- −DEX bytecode is not human source
- −Repack cannot reinstall
Why convert OTB to APK?
There is a concrete reason this conversion exists: Niche format — few modern readers APK sidesteps that — Everything an Android app ships If that is your situation, the tool above settles it in seconds, entirely on your device.
Frequently asked questions
Is this OTB to APK converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Will I lose quality converting OTB to APK?
No — APK is a lossless format, so every pixel of the converted image matches your original OTB file. You can also adjust the quality/size balance before converting when the target format supports compression.
Will transparent areas survive the conversion to APK?
Transparency is kept whenever APK actually supports an alpha channel. If the target format has none (like JPG), transparent areas are flattened onto a white background — that is a property of the format, not of this tool.
What happens to EXIF data and other metadata?
Conversions here re-encode the image, and re-encoding generally does not carry the original metadata over. If the EXIF data of your OTB files matters (camera model, GPS, timestamps), keep the original file as the master and treat the converted copy as the shareable version.