Where JP2 files come from
JPEG 2000 was designed as a successor to JPEG with better compression and features such as lossless mode and progressive zooming into huge images. It found niches rather than mass adoption:
- digital libraries and archives, including many scanned books and newspapers
- medical imaging within DICOM files
- satellite and aerial imagery and maps
- digital cinema, where films are distributed as JPEG 2000 frames
- some PDF scans, which embed JPEG 2000 images
If you’ve downloaded an image from an archive or library and it ends in .jp2, this is how to open it.
How to use it
- Choose a quality: 90% preserves fine detail in scans.
- Choose your JP2 files or drop them on the box above.
- Download each JPG, or all of them as a ZIP.
Large images
JPEG 2000 is often used for very large scans and maps, sometimes hundreds of megapixels. These convert on a computer but may exceed a phone’s memory. If an image is huge, consider resizing the JPG afterwards for sharing.
What changes
- Format: JPEG 2000 wavelet data becomes standard JPG.
- Colour: converted to 8-bit sRGB; high-bit-depth images are reduced to 8 bits.
- Transparency: filled with white, since JPG has none.
- Dimensions: unchanged.
Privacy
Files are decoded in your browser and never uploaded.
Images from digital archives
Online libraries and archives often offer their highest-quality scans as JPEG 2000, alongside smaller JPG previews. If you download a JP2 for its detail, converting at 90–95% quality keeps that detail in a file any app can open. Check the archive’s terms of use before reusing images, especially for publication.
Other JPEG 2000 extensions
Files ending in .j2k, .jpf or .jpx are variants of JPEG 2000 and convert the same way.
Questions
What is a JP2 file?
JP2 is the file format of JPEG 2000, an image standard from 2000 that uses wavelet compression. It's common in digital archives, scanned books, medical imaging, satellite maps and digital cinema.
Why can't I open JP2 files?
JPEG 2000 never became mainstream, so most browsers, phones, photo apps and websites don't support it. Converting to JPG solves that.
Does converting lose quality?
JPG is lossy, so a little fine detail is removed. At 90% quality the difference is very hard to see. Use the universal image converter to get PNG if you need a lossless copy.
Why is the first conversion slower?
JPEG 2000 is decoded by ImageMagick, which loads (about 15 MB) the first time. Later conversions start straight away.
Last reviewed 1 November 2026