PPTX to OTB Converter

Convert PPTX to OTB Nokia bitmaps — free online

Drop files here. 1 GB maximum file size or Sign Up
to
Facebook Amazon Microsoft Tesla Nestle Walmart L'Oreal

Slides to Nokia Bitmaps

Render PPTX graphics as OTB on-the-air bitmaps — create custom operator logos and icons for Nokia devices from your presentation artwork.

Tiny Output Size

OTB files are extremely small — 1-bit monochrome at low resolution. Your PPTX graphics become lightweight images that fit on resource-limited mobile devices.

Cloud Conversion

No Nokia tools or mobile development kits required. Upload your PPTX to Convertio and download ready-to-use OTB bitmaps from any device online.

How to convert PPTX to OTB

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose otb or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your otb file right afterwards

About formats

PPTX is the default file format for Microsoft PowerPoint presentations since Office 2007, based on the Office Open XML (OOXML) standard published as ECMA-376 and later adopted as ISO/IEC 29500. A PPTX file is a ZIP archive containing XML documents that describe slide content, layouts, themes, relationships, and metadata in a structured, human-inspectable hierarchy. Each slide, slide layout, and slide master is stored as a separate XML part, with media assets (images, audio, video) and embedded objects kept in dedicated directories within the package. The XML foundation enables programmatic creation and manipulation of presentations using standard XML tools and libraries — developers can generate, modify, or extract content from PPTX files without requiring PowerPoint itself. One significant advantage is openness and interoperability: the fully documented OOXML specification allows any software to read and write PPTX files, and the format is supported by LibreOffice Impress, Google Slides, Apple Keynote, and numerous other tools. Built-in ZIP compression is another practical strength — PPTX files are typically 50-75% smaller than equivalent PPT files, reducing storage and transfer costs. The format supports all modern PowerPoint features including SmartArt, 3D models, morph transitions, embedded fonts, accessibility metadata, and co-authoring capabilities. PPTX has become the standard interchange format for presentation content worldwide.
Developer: Microsoft
Initial release: January 30, 2007
OTB (Over-the-Air Bitmap) is a monochrome image format developed by Nokia as part of their Smart Messaging specification in 1997, designed for transmitting small graphics — operator logos, group graphics, and picture messages — to Nokia mobile phones via SMS. OTB files contain 1-bit (black and white) images at small fixed resolutions, typically 72x14 pixels for operator logos and 72x28 pixels for group graphics, encoded in a compact binary format suitable for embedding within the payload of SMS text messages. The format uses a simple structure: a header byte indicating whether the image is an operator logo or group graphic, width and height values, and the raw bitmap data where each bit represents one pixel packed eight per byte. The extremely tight format — designed to fit within a single SMS message (140 bytes maximum payload, shared with addressing overhead) — reflects the severe constraints of mobile communication in the late 1990s. Nokia's Smart Messaging system was one of the first commercial implementations of rich content delivery to mobile phones, and OTB images represented the entire visual content capability of Nokia handsets before MMS and mobile data browsing arrived. One advantage is the format's historical role as a pioneer of mobile visual messaging: OTB images were among the first graphics that ordinary consumers could send to each other's phones, predating MMS, camera phones, and smartphones by nearly a decade. The format's minimal footprint is another characteristic — entire images fit in a few dozen bytes, reflecting an era of extreme bandwidth constraints. OTB files are supported by ImageMagick, various Nokia phone management tools, and specialty mobile format utilities.
Developer: Nokia
Initial release: 1997

Frequently Asked Questions

Why convert PPTX to OTB?

OTB lets you put slide graphics on Nokia phones as on-the-air bitmaps — useful for creating custom logos, icons, or operator graphics from presentation artwork.

How do I open OTB files?

Nokia phone management software and ImageMagick handle OTB files. XnView can also display on-the-air bitmaps on desktop computers for previewing.

What resolution are OTB images?

OTB bitmaps are typically small — designed for Nokia phone displays. The exact dimensions depend on the target device, but sizes are usually under 100x100 pixels.

Does OTB support color?

No — OTB is strictly 1-bit monochrome. Each pixel is black or white, consistent with the limited display capabilities of older Nokia mobile hardware.

Is PPTX to OTB free?

Convertio converts PPTX to OTB at no cost. Premium plans unlock batch conversion, faster processing, and larger upload allowances.

Is OTB used outside Nokia devices?

OTB was created specifically for Nokia on-the-air graphics. Outside that ecosystem, it serves as a simple 1-bit bitmap for retro mobile enthusiasts and collectors.