PNG8 to OTB Converter
Processing entirely on your device — large files may take a moment.
PNG (8-bit Indexed) and Nokia OTA Bitmap exist for different jobs: PNG8 is PNG with an 8-bit indexed palette — at most 256 colors, the "GIF-quality" PNG that Fireworks era designers exported for tiny file sizes. Convert images to 1-bit OTB for retro phone displays.
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 PNG8 to OTB
- 1
Select your files
Drag & drop your PNG8 files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to OTB". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted OTB file individually, or grab everything at once as a ZIP archive.
About the PNG8 format
PNG was created in 1996 as a free, open replacement for the patent-encumbered GIF, and it has been the reference lossless image format ever since. Pixels are compressed with the DEFLATE algorithm (the same one inside ZIP files), which reproduces the original image exactly — bit-for-bit — while supporting full 8-bit or 16-bit alpha transparency. Screenshots, logos, icons, charts and anything with text or sharp edges should live in PNG.
Because it never discards information, PNG files of photographs are several times larger than JPG — that is the price of perfection. Modern PNG encoders add filters per scanline that make screenshots and flat-color graphics compress surprisingly well. PNG also became the base of APNG, the animation extension that browsers play natively.
+ Strengths
- ✓Truly lossless — every pixel survives exactly as it was
- ✓Full alpha transparency with smooth edges, not 1-bit masks
- ✓Open standard, unpatented, with excellent tooling everywhere
- ✓Ideal for text, line art and flat-color graphics — sharp edges stay sharp
! Limitations
- −Photographs become several times larger than JPG
- −Base format has no animation (that is the APNG extension)
- −16-bit or high-resolution PNGs can grow very heavy
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
Why convert PNG8 to OTB?
Converting makes sense where the strengths of OTB meet what PNG8 cannot give you. Written natively by ImageMagick Meanwhile Photographs become several times larger than JPG One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this PNG8 to OTB 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 PNG8 to OTB?
No — OTB is a lossless format, so every pixel of the converted image matches your original PNG8 file. You can also adjust the quality/size balance before converting when the target format supports compression.
Can I convert several PNG8 files at once?
Yes — drop as many files as you like into the tool and they are converted in one batch. When more than one file comes out, everything is bundled into a ZIP for a single download.
Will transparent areas survive the conversion to OTB?
Transparency is kept whenever OTB 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.