Free online JPX to PNG converter

A browser, editor, document system, or device may require PNG when it cannot open a JPEG 2000 image stored as JPX. Converting also provides a broadly supported raster copy for sharing and editing, although the PNG may be larger than the source.

What the JPX format is

JPX is the file format defined by JPEG 2000 Part 2 (ISO/IEC 15444-2). It can contain JPEG 2000 image data with features such as multiple components, tiles, resolution levels, layers, transparency, and extended metadata. The related extensions .jpx and .jpf are used for JPX files; basic JPEG 2000 files commonly use .jp2.

Specialized scanning, medical-imaging, geographic-information, archival, digital-cinema, and professional imaging systems use JPEG 2000 formats. A JPX file may therefore arrive from a high-resolution scanner, imaging application, document system, or archive rather than from a typical consumer photo program.

What the PNG format is

PNG (Portable Network Graphics) is a lossless raster format supported by web browsers, operating systems, image editors, and document software. It supports indexed color, grayscale, RGB color, 8-bit or 16-bit channels, and an alpha channel for transparency.

PNG is well suited to screenshots, diagrams, interface graphics, text-heavy images, and images that will be edited repeatedly. Its lossless encoding preserves the pixels produced during conversion, but photographic PNG files are often much larger than JPEG or JPEG 2000 files because PNG does not discard image data through lossy compression.

How to convert the file

Using 101convert.com

For a single file, use the JPX-to-PNG converter on 101convert.com for free without installing software. Select or upload the .jpx file, choose PNG if the format is not selected automatically, start the conversion, and download the resulting .png file. Do not upload confidential, personal, medical, or regulated images to an online service unless its handling policies meet your requirements.

Using ImageMagick

ImageMagick is suitable for local and batch conversion, but its installation must include JPEG 2000 decoding through an OpenJPEG or equivalent delegate. Check that the file can be read before converting:

magick identify input.jpx

Convert one image with:

magick input.jpx output.png

PNG compression is lossless; setting a higher compression level changes encoding time and file size, not image quality:

magick input.jpx -define png:compression-level=9 output.png

On a Unix-like shell, convert each JPX file in a folder to a correspondingly named PNG:

for f in *.jpx; do magick "$f" "${f%.*}.png"; done

If ImageMagick reports that no JPEG 2000 decoder is available, install a build with OpenJPEG support or use a desktop image application that can open JPX and choose File → Export or File → Save As, then select PNG. Applications such as XnConvert can be used for graphical batch conversion when their installed format support recognizes the file.

Quality and compatibility limits

PNG encoding is lossless from the pixels decoded from JPX, but it cannot restore detail already lost in a lossy JPEG 2000 stream. Conversion can also omit custom JPX metadata, color-management information, layers, or unusual image components; PNG does not represent every JPX feature.

Inspect the converted file's dimensions, color profile, bit depth, transparency, and visual appearance. A JPX containing multiple images, resolutions, layers, or pages may be rendered as only the default image or first image. If those structures must remain editable or intact, retain the original JPX and use JPEG 2000 software that explicitly supports the required JPX features instead of relying on a single PNG export.