.jp2 File Extension

What kind of file is a .jp2?

A .jp2 file is usually a still image in the JPEG 2000 Part 1 file format. It uses the registered image/jp2 MIME type. The JP2 container wraps a JPEG 2000 codestream with information needed to interpret the image, such as dimensions and color space.¹

JPEG 2000 can compress pixels losslessly or lossily. The extension does not reveal which mode an encoder used, so do not assume that every .jp2 is an archival master.

A conforming JPEG 2000 family file begins with this 12-byte signature:

00 00 00 0C 6A 50 20 20 0D 0A 87 0A

Check the signature and the file's internal boxes instead of trusting its name. Raw JPEG 2000 codestreams commonly use .j2k, .j2c, or .jpc; they are not JP2 containers.¹

How do I open a .jp2 on my computer?

Use software with an explicit JPEG 2000 decoder:

• On macOS, Apple Preview opens JPEG 2000 images and can export them as JPEG, PNG, TIFF, or other formats.²
• On Windows or macOS, Adobe Photoshop lists JPEG 2000 among its supported import and export formats.³
• On Linux, macOS, or Windows, ImageMagick can read and write JP2 when its JPEG 2000 delegate is installed.⁴

Current web browsers are not a dependable way to view JP2 files. Convert an image or provide a more broadly supported fallback for web delivery.

Poly support for .jp2

Poly stores, syncs, shares, versions, and finds .jp2 files by name. It recognizes the extension and its registered media type, but does not currently decode the pixels. Consequently, Poly does not create a thumbnail, extract JPEG 2000 metadata, build a visual-search representation, show an image preview, or make the picture available to the Poly agent.

Download the original and open it in a compatible application when you need to inspect or convert it. This is Storage Only support because the image content itself is not processed.

History of .jp2

JPEG 2000 was developed by the Joint Photographic Experts Group as a more flexible successor to the original JPEG family. ISO published the first edition of the Part 1 core coding standard in December 2000.⁵

Its wavelet-based design supports lossless and lossy coding, progressive decoding by quality or resolution, high bit depths, and access to selected image regions.⁶ These capabilities led to adoption in specialized fields such as medical and satellite imaging, digital cinema, and cultural heritage. The shorter, older .jpg format nevertheless retained much wider everyday compatibility.

RFC 3745 later registered image/jp2, naming .jp2 as the preferred suffix and .jpg2 as an alternative.¹

Working with .jp2 and alternatives

Choose a conversion target based on what must survive:

ImageMagick documents the basic command magick input.jp2 output.png.⁴ Before replacing an original, compare pixel dimensions, bit depth, color profile, alpha, and metadata. Converting a lossy JP2 to PNG prevents another lossy save but cannot recover discarded detail.

JP2 may contain XML, rights information, resolution data, and application-specific metadata. A raster-only conversion can silently omit those fields. Use a maintained decoder for untrusted files, and test unusually large images or specialized profiles with the exact application used in production.