Convert CALS images or ANTLR grammars (G4) online for free
The converter easily converts your G4 images or grammars to various formats - free and online. No ANTLR or or other Raster Image software needed.
To convert other file formats to the "Group 4 Fax Image" file type, you need software like ANTLR or a similar tool.
A .G4 file typically represents either a CALS Group 4 raster image or an ANTLR v4 grammar file. In the imaging context, .G4 or CCITT Group 4 files are 1-bit, black-and-white image formats historically used by the US Department of Defense, the European Patent Office, and legacy fax machines (such as Brother fax devices). Often, these are raw image data streams or wrapped inside a TIFF container. In software development, a .G4 file contains syntax rules used by the ANTLR Parser Generator to process structured text or computer code.
The main disadvantage of .G4 image files is their obsolescence. They are proprietary or legacy formats completely unsupported by modern web browsers, standard mobile devices, and most default operating system viewers. Opening a .G4 patent or fax document usually requires installing outdated software or enterprise document management tools. ANTLR .G4 files, while just plain text, lack readability for non-developers and require specific IDE plugins to avoid syntax errors.
To make .G4 image files usable, you must convert them. For web display or general sharing, convert to PNG or JPG. For long-term archiving or printing, convert to PDF/A. If you have an ANTLR grammar file, you can convert it to standard TXT to ensure it opens safely anywhere. Just drag and drop your file here to analyze and convert it - free, online, and without installing software.
Use Convert.Guru to open and convert your G4 file.
Users also converted ICS, FNA, IGNORE and G3 files.
If you want to convert G4 file to WEBP, CUR or PSB, you can use ANTLR or similar software from the "Legacy Imaging or Parser Grammar" 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 G4, try ANTLR or another comparable tool in the "Legacy Imaging or Parser Grammar" 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 G4 converter.