WOFF to JBG Converter

Render web fonts as JBIG-compressed monochrome images online

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Superior Compression

JBIG produces extremely compact monochrome images — font glyph renders compress better than with Group 4 or other bi-level encodings.

Document Imaging

Convert WOFF web fonts into JBIG images optimized for document management, text archival, and efficient monochrome storage.

Secure Files

Uploaded WOFF files are removed after conversion, and JBG outputs are deleted within 24 hours to protect your font data.

How to convert WOFF to JBG

1

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

2

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

3

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

About formats

WOFF (Web Open Font Format) is a web font container format developed by Jonathan Kew, Tal Leming, and Erik van Blokland, and standardized by the W3C as a Recommendation in December 2012. The format wraps existing TrueType or OpenType font data in a compressed container with additional metadata, specifically designed for efficient delivery over HTTP as part of web pages using the CSS @font-face rule. WOFF applies table-level zlib compression to the font data, typically achieving 40-50% size reduction compared to raw TTF or OTF files, while preserving every table and glyph exactly. An extended metadata block allows foundries to embed licensing information, credits, and descriptions that travel with the font file. WOFF was created to address a practical impasse: type foundries were reluctant to allow their fonts on the web in raw TTF/OTF form (easily installable as desktop fonts), while the web standards community needed a freely implementable font delivery mechanism. One advantage is universal browser support — every modern browser across desktop and mobile platforms renders WOFF natively, making it the baseline format for web typography. The distinct file signature and container structure also provides a licensing benefit, giving foundries a format distinguishable from desktop fonts while remaining technically straightforward. WOFF 2.0, standardized in March 2018, replaces zlib with Brotli compression for an additional 20-30% size reduction and has achieved similarly broad browser adoption. Together, WOFF and WOFF2 enabled the custom web typography revolution that transformed web design from a handful of system fonts to millions of typeface options.
Developer: W3C
Initial release: December 13, 2012
JBG is a file extension for images compressed using the JBIG (Joint Bi-level Image experts Group) standard, formally ITU-T Recommendation T.82, completed in 1993 as a successor to the Group 3 and Group 4 fax compression standards. JBIG compression is designed for bi-level (black and white) images but can also handle grayscale and limited-color images by encoding each bit plane separately. The algorithm uses a form of arithmetic coding guided by an adaptive context model: for each pixel, the encoder examines a template of surrounding already-coded pixels to build a probability estimate, then feeds this estimate to a QM-coder (a variant of the Q-coder arithmetic coder) that produces a highly efficient binary output. JBIG achieves 20-40% better compression than Group 4 on typical document images, with the improvement being even larger on halftoned photographs and images with gradual density transitions where Group 4's simple run-length approach is less effective. The standard supports progressive encoding, where a low-resolution version of the image is transmitted first and progressively refined — useful for fax-like applications where the receiver can begin displaying the image before the full-resolution data arrives. One advantage is superior compression of documents containing halftone images: newspapers, magazines, and marketing materials that mix text with photographic halftones compress dramatically better with JBIG than with Group 3/4. The standard's ITU-T backing ensures it is implemented in document imaging hardware and software worldwide. JBG files are supported by ImageMagick and various document imaging tools.
Initial release: 1993

Frequently Asked Questions

Why convert WOFF to JBG?

JBIG compression excels at monochrome images — text and glyph renders compress extremely well, producing very small files ideal for document imaging.

How do I open a JBG file?

The jbig-kit library and ImageMagick handle JBG files. Some document management systems and fax applications also support JBIG compression natively.

What is JBIG compression?

JBIG (Joint Bi-level Image Experts Group) is a lossless compression standard optimized for bi-level (black and white) images like text documents.

Is JBG better than TIFF for text?

For monochrome text images, JBIG compression typically outperforms TIFF Group 4, producing files 20-50% smaller while maintaining lossless quality.

Is WOFF to JBG free?

Yes, Convertio provides free WOFF to JBG conversion online — no document imaging software or compression tools required.