G4 to HEIC Converter

Free G4 to HEIC conversion — browser-based tool

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Private & Secure

Uploaded G4 files are erased right after conversion. HEIC results are automatically deleted within 24 hours.

Fax Content Access

Make G4 content viewable in HEIC format — no fax machines or specialized legacy viewers required.

Nothing to Install

The G4 to HEIC conversion happens in your browser — no software to download or configure on your device.

How to convert G4 to HEIC

1

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

2

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

3

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

About formats

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
HEIC (High Efficiency Image Container) is Apple's branded implementation of the HEIF (High Efficiency Image File Format) standard that uses HEVC (H.265) as its image compression codec. Apple adopted HEIC as the default photo format on iPhones and iPads starting with iOS 11 in September 2017, replacing JPEG for newly captured images. HEIC files store photographs compressed with the intra-frame coding mode of the HEVC video codec, which applies sophisticated prediction, transform, and entropy coding techniques that achieve roughly 50% better compression than JPEG at equivalent visual quality. The ISOBMFF (ISO Base Media File Format) container supports multiple images in a single file, enabling Live Photos (a still plus a short video clip), burst sequences, depth maps from dual-camera systems, and HDR gain maps that allow compatible displays to render extended dynamic range. HEIC also stores alpha channels, auxiliary images for computational photography features (portrait mode depth data, semantic segmentation masks), and comprehensive EXIF/XMP metadata. One advantage is storage efficiency: iPhones shooting HEIC use roughly half the storage of equivalent JPEG captures with no visible quality loss, a significant benefit on devices where storage is finite and photos accumulate rapidly. The format's integration with Apple's ecosystem is another key strength — HEIC files are natively supported across macOS, iOS, iPadOS, and iCloud Photos, and automatic JPEG transcoding during file sharing ensures compatibility when sending photos to non-Apple devices. HEIC can also be opened by Windows 10/11 (with codec), GIMP, ImageMagick, and Adobe Lightroom.
Developer: MPEG / Apple
Initial release: 2015

Frequently Asked Questions

Why convert G4 to HEIC?

G4 files require specialized fax viewers. Converting to HEIC lets anyone open the content easily.

How do I view a HEIC file?

Use Apple devices natively, Windows with HEIF extension, or GIMP to view HEIC files.

Will my G4 content stay sharp in HEIC?

Full resolution is preserved during G4 to HEIC conversion. Text and graphics remain sharp and clear.

Is there a charge for G4 to HEIC?

Basic conversions are free. Premium subscriptions provide priority processing and expanded daily capacity.

Can I process many G4 files in one go?

Absolutely — add several G4 files at once. Each gets its own HEIC conversion and individual download link.

What happens to my files after conversion?

Your original G4 upload is deleted right after processing. The converted HEIC file is removed within 24 hours.