PPT to G3 Converter

Render PPT slides as G3 fax images — free online

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Direct Fax Encoding

Convert PPT presentations into raw G3 fax data — the exact encoding fax machines use, bypassing intermediate format wrappers entirely.

Quick Processing

Upload your PPT and get G3 output fast. Cloud servers handle the monochrome rendering and fax compression in seconds.

Privacy Protected

Your uploaded PPT is erased immediately after conversion. G3 output files are automatically deleted from servers within 24 hours.

How to convert PPT to G3

1

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

2

Choose g3 or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your g3 file right afterwards

About formats

PPT is the binary file format of Microsoft PowerPoint, the presentation software first released on April 20, 1987 for the Apple Macintosh and later ported to Windows. The PPT format stores presentations as OLE2 compound documents — a structured binary container developed by Microsoft that organizes slides, text content, images, charts, animations, transitions, speaker notes, and embedded objects across multiple internal streams. Each slide is composed of shape records describing text boxes, auto-shapes, images, tables, and other elements with associated formatting properties including fonts, colors, positioning, and animation sequences. The format evolved substantially through multiple PowerPoint versions, with the PowerPoint 97 release establishing the compound document structure that remained standard through PowerPoint 2003. One advantage is universal recognition — PPT files are understood by virtually every presentation application across all platforms, from Microsoft Office to LibreOffice Impress, Google Slides, and Apple Keynote, making it one of the most portable document formats ever created. The format's mature feature set is another strength: PPT files support complex slide masters, custom animations with timing sequences, embedded multimedia, OLE-linked objects, and VBA macros for automation. Although Microsoft introduced the XML-based PPTX format with Office 2007, the binary PPT format remains widely encountered in archived presentations, corporate document repositories, and organizations that maintain compatibility with older PowerPoint versions.
Developer: Microsoft
Initial release: April 20, 1987
G3 is a monochrome image format based on the ITU-T Group 3 facsimile coding standard (Recommendation T.4), ratified by the CCITT in 1980 as the universal compression method for fax transmission over telephone networks. G3 files contain 1-bit (black and white) image data encoded using Modified Huffman (MH) one-dimensional coding, where each scanline is independently compressed by replacing runs of consecutive white or black pixels with variable-length codewords from a predefined Huffman table optimized for typical document content. The standard also defines an optional two-dimensional coding mode (Modified READ) that encodes each line as differences from the previous line, achieving better compression for pages with vertical redundancy. Standard G3 resolution is 204 pixels per inch horizontally and either 98 (standard) or 196 (fine) pixels per inch vertically, producing the characteristic slightly-stretched appearance of received fax documents. The encoding was carefully optimized for the real-time transmission constraints of 1980s modems operating at 2400 to 14400 bps, where encoding and decoding speed had to match the communication channel rate. One advantage is universal telecommunications compatibility: Group 3 encoding remains the mandatory baseline codec for every fax machine manufactured, ensuring that G3 image data can be transmitted to or received from any fax device worldwide. The format's efficiency for document content is another strength — the Huffman tables were statistically tuned to the run-length distributions found in business documents, and typical pages compress to under 30 KB. G3 files are supported by LibreOffice, ImageMagick, and fax server software.
Developer: ITU-T (CCITT)
Initial release: 1980

Frequently Asked Questions

Why convert PPT to G3?

G3 is the raw encoding used by Group 3 fax machines. Converting slides to G3 prepares them for direct fax transmission or integration into fax server workflows.

What opens G3 files?

ImageMagick, IrfanView, and fax server applications read raw G3 data. Unix tools like viewfax also display the format directly from the command line.

How does G3 differ from FAX format?

G3 contains the raw Group 3 compressed bitstream without a file header wrapper. It is a lower-level representation of the same fax encoding standard.

Will my slides lose color in G3?

Yes — G3 is strictly monochrome. Color content from PPT slides is reduced to black and white using threshold or dithering algorithms during conversion.

Is PPT to G3 free?

Convertio provides PPT to G3 conversion at no charge for regular use. Premium tiers unlock higher file size limits and priority processing.