CMX to G4 Converter

CMX to G4 online — Group 4 fax compression free

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Advanced Fax Compression

G4 compresses more efficiently than G3. CMX to G4 conversion produces optimal files for digital fax and document archival.

Instant Output

G4 files are small. CMX to G4 conversion is practically instant — upload, convert, and download within seconds.

Browser-Based

No fax software installation needed. Convert CMX to G4 from any web browser on any operating system.

How to convert CMX to G4

1

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

2

Choose g4 or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your g4 file right afterwards

About formats

CMX (Corel Presentation Exchange) is a vector graphics exchange format developed by Corel Corporation, introduced with CorelDRAW 5 in September 1994. Designed as a cross-application interchange format within the Corel product suite, CMX stores vector objects, text, bitmaps, and rendering attributes in a structure accessible to CorelDRAW, Corel PHOTO-PAINT, Corel Presentations, and other Corel applications without requiring each program to understand the full CDR native format. The format uses a chunk-based architecture that encodes geometric primitives, fill patterns, outline properties, and color definitions in a standardized way, supporting both 16-bit and 32-bit variants. CMX gained significance beyond the Corel ecosystem through its adoption by third-party applications and its role in clipart distribution — many vector art collections from the mid-to-late 1990s shipped in CMX format. One advantage is interoperability within design workflows: CMX provided a practical bridge for moving vector content between different Corel applications while preserving visual fidelity, gradients, and transparency attributes. The format's inclusion of both vector and bitmap data within a single file is another strength, allowing complex mixed-media illustrations to be exchanged as self-contained units. Microsoft also added CMX import support to some Office applications, expanding the format's reach. While modern Corel applications primarily use CDR for native work and export to SVG, PDF, or EPS for interchange, CMX files from the CorelDRAW era remain widely encountered in legacy asset libraries.
Developer: Corel Corporation
Initial release: 1994
G4 is a monochrome image format based on the ITU-T Group 4 facsimile coding standard (Recommendation T.6), ratified by the CCITT in 1984 as an improvement over Group 3 for use on error-free digital networks like ISDN rather than analog telephone lines. G4 files contain 1-bit image data compressed using exclusively two-dimensional Modified Modified READ (MMR) coding, where each scanline is encoded as a set of differences (changing elements) relative to the line above it. By eliminating the one-dimensional coding fallback and the end-of-line synchronization markers required by Group 3, G4 achieves 20-50% better compression ratios on typical document pages while producing a simpler, more regular bitstream. The format is most commonly encountered as a compression method within TIFF files (TIFF compression tag 4), where it became the standard archival format for scanned documents in enterprise document management, government records, and legal imaging systems. G4 compression is specified at 200, 300, or 400 dpi depending on the scanning application, with 300 dpi being the most common for archival-quality document imaging. One advantage is exceptional compression efficiency for document content: G4's two-dimensional prediction exploits the strong vertical correlation in text and line art pages, typically compressing a 300 dpi letter-size page to 30-50 KB — roughly half the size of equivalent Group 3 encoding. The format's entrenchment in document management infrastructure is another strength — G4 TIFF is the mandated format for many government digital records systems, court filing systems, and corporate archives, supported by every enterprise imaging platform.
Developer: ITU-T (CCITT)
Initial release: 1984

Frequently Asked Questions

Why convert CMX to G4?

G4 is the ITU Group 4 fax compression standard — more efficient than G3. Converting CMX to G4 produces compact images for digital fax workflows.

What uses G4 files?

Fax servers, document management systems, and TIFF-based archival workflows frequently use G4 compression for scanned documents.

Is G4 better than G3?

G4 provides better compression ratios than G3. It is designed for error-free channels like digital networks rather than phone lines.

Is the converter free?

Basic CMX to G4 conversion is free. Premium plans add capacity for enterprise document processing.

How fast is it?

G4 images are compact, so conversion from CMX finishes in seconds on Convertio cloud servers.