Convert G3 files online for free
The converter easily converts your G3 file to various formats - free and online. No Photoshop or extra software needed.
The converter also works in reverse, so you can convert other Raster Image formats to G3 with high quality output.
The .g3 file extension is most commonly associated with the CCITT Group 3 compression standard, a legacy raster graphics format designed for transmitting documents via fax machines. These files consist of raw, 1-bit monochrome image data optimized to minimize transmission time over telephone lines. A major problem for users is that raw .g3 files are often "headerless," meaning they lack the standard file signatures found in modern formats like TIFF or JPG. Consequently, most default image viewers (such as Windows Photos or macOS Preview) cannot open them directly, or they may display a distorted, scrambled image if the width isn't guessed correctly. To make these documents accessible, users typically need to convert them to PDF (for archiving multi-page faxes) or PNG (for lossless viewing).
Note: In modern workflows, the .g3 extension is also utilized by Pupil Labs for eye-tracking gaze data and occasionally by GoPro for telemetry metadata. If your file opens as text in a code editor, it is likely a data log rather than an image. For these cases, the goal is often converting the internal JSON structure to CSV for analysis.
Use Convert.Guru to open and convert your G3 file.
Users also converted 360, EVE and RESOURCE files.
If you want to convert G3 file to WEBP, CUR or PSB, you can use GIMP or similar software from the "Fax Image Storage" category. In the File menu, look for Save As… or Export….
To convert RAW, PNG, AI, NEF, PSB, DNG, SVG, GIF, EPS, JPG, ARW or PDF files to G3, try GIMP or another comparable tool in the "Fax Image Storage" category.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our G3 converter.