CDT to G3 conversion is the process of transforming a CorelDRAW Template (CDT) file into a G3 (Group 3 Fax) raster image format. This conversion rasterizes vector and template elements from CDT into bilevel or grayscale fax-friendly images suitable for legacy fax transmission or archival.
Related guides
Practical guides to help you choose formats, preserve quality, and avoid common conversion problems.
WebP has quietly become the default image format of the modern web, delivering 25-35% smaller files than JPG and PNG with universal browser support. This 2026 guide covers current adoption stats, browser compatibility, WordPress integration, conversion workflows, and when to choose WebP over AVIF for optimal Core Web Vitals performance.
Read guide →Not sure whether to save your image as PNG or JPG? This detailed comparison covers compression, transparency, file size, web performance, and real-world use cases so you can pick the right format every time — with conversion links when you need to switch.
Read guide →Learn how to convert HEIC to JPG for maximum compatibility. This guide explains what HEIC is, why iPhones use it, the key differences between HEIC and JPG, and walks through every conversion method including online tools, iPhone settings, Windows, and Mac.
Read guide →Drag your .CDT file from your computer or use the browse function.
Confirm .g3 as the selected destination format.
Click "Convert" and download your converted .G3 file once ready.
CDT files typically use the MIME type application/vnd.cdt and are common in CAD and drawing software. G3 files use the image/g3fax MIME type and are designed for compressed fax image data using Group 3 fax encoding standards. Codecs supporting G3 handle efficient black-and-white image compression for fast transmission.
The G3 (.G3) format is commonly used for image. Understanding its characteristics can be helpful when converting to or from other formats like CDT.
While specific technical details aren't available here, G3 files generally serve the purpose of storing image effectively within their domain.
Our Online CDT to G3 Converter offers a simple and efficient way to convert your CDT files into the G3 format without downloading any software. Designed for users in the Drawing category, this tool ensures high-quality conversions with minimal effort.
CDT files are primarily used for detailed drawing projects, supporting rich vector data. In contrast, G3 is a compressed bitmap format optimized for fax and document transmission, offering smaller file sizes but less detail. Choosing G3 is ideal for quick sharing and compatibility with fax systems.
Keep vector elements and text preserved: convert text to curves or embed fonts in the source CDT before rasterizing to avoid font substitution.
Optimal file sizes: aim for 50–500 KB per page after G3 compression for single-page templates; very complex pages may exceed 1 MB before compression.
Quality preservation: use appropriate dithering and a higher source resolution (300 dpi) before downsampling to 200 dpi G3 to retain detail in line art and small text.
Batch conversion: process CDT files as PDFs or exported high-resolution TIFFs first, then apply G3 compression in bulk to ensure consistent settings across multiple files.
This CDT to G3 converter saved me hours of manual file conversion.
Emma R.
Architect
Reliable and easy to use, perfect for quick file sharing.
Mark L.
Engineer
The quality of converted files exceeded my expectations every time.
Lisa M.
Designer
Start your free CDT to G3 conversion now.
Drag your file here to to upload.
Up to 250MB
Format-specific limitation: G3 is a bilevel fax format — color, gradients, and complex transparent vector effects will be flattened and may lose fidelity when converted.