JPEG-XS

JPEG XS Image

image/jxs Released 2019 · by Joint Photographic Experts Group (JPEG) / intoPIX

JPEG XS (Extra Speed) is a low-latency, lightweight image and video compression standard defined by ISO/IEC 21122. It is engineered to replace uncompressed video in live production and IP broadcasting workflows (like SMPTE ST 2110), offering visually lossless quality, microsecond-level latency, and extremely low computational complexity.

Professional & Video Production Transparency Animation ✦ HDR Production Ready

Technical Specifications

MIME Type

image/jxs

Extensions

.jxs

Container

ISOBMFF (ISO/IEC 21122-3) or Raw Codestream

Compression

Lossy (Visually Lossless) & Mathematically Lossless

Algorithms

JPEG XS (Low-complexity wavelet transform)

Color Depth

8-bit, 10-bit, 12-bit, 14-bit, 16-bit

Metadata

EXIF XMP ICC

Capabilities

Transparency

Animation

Progressive Loading

Alpha Channel

HDR Support

Official Specification

Aliases: video/jxs

Magic Bytes & HTTP Headers

File Signature (Magic Bytes)

FF 10 (Codestream) / XX XX XX XX 66 74 79 70 6A 78 73 20 (ISOBMFF)

ASCII: .. / ....ftypjxs

HTTP Headers

Content-Type: image/jxs

HTML Accept Attribute

accept="image/jxs, .jxs"

Browser Support Matrix

Browser	Status	Min Version
Chrome	Not Supported	—
Firefox	Not Supported	—
Safari	Not Supported	—
Edge	Not Supported	—
Internet Explorer	Not Supported	Legacy

Advantages & Limitations

Advantages

Provides sub-millisecond encoding/decoding latency, essential for live production and gaming
Extremely lightweight, requiring very little CPU, GPU, or FPGA memory to process
Replaces uncompressed video links (like SDI or HDMI) over standard Ethernet networks with visually lossless quality

Limitations

Compression ratios are typically much lower (between 2:1 and 10:1) compared to heavy codecs like HEVC or AV1
Zero support in web browsers or standard consumer devices
Primarily licensed to hardware manufacturers and professional software ecosystems

Developer Code Snippets

import magic
print(magic.from_file('stream.jxs', mime=True)) # May default to generic 'application/octet-stream' without custom rules

const FileType = require('file-type');
const type = await FileType.fromFile('stream.jxs');
console.log(type?.mime); // Standard libraries may struggle to differentiate without specific JXS updates

import "net/http"
// Requires checking for the FF 10 codestream marker or the 'jxs ' ISOBMFF brand.

$mime = mime_content_type('stream.jxs');
echo $mime; // Standard systems will map this to application/octet-stream

File Detection Steps

How to programmatically detect a image/jxs file by reading its raw bytes:

1 Check the first two bytes for the raw codestream signature (FF 10)
2 Check for the standard ISOBMFF 'ftyp' box starting at byte offset 4 and verify the brand string 'jxs ' starting at byte offset 8

Software Support

F

FFmpeg (with external libraries)

i

intoPIX FastTICO-XS

ImageMagick

Conversion Tools

Share & Embed

Markdown Badge

[![JPEG-XS Format](https://freewebptojpg.com/mime/image/jpeg-xs/badge.svg)](https://freewebptojpg.com/mime/image/jpeg-xs)

Interactive iframe Widget

<iframe src="https://freewebptojpg.com/mime/image/jpeg-xs/embed" width="100%" height="280" style="border:1px solid #cbd5e1;border-radius:8px;" title="JPEG-XS Specs"></iframe>

JSON API

All data on this page is available as a free, open JSON API. Use it in your project, documentation, or tooling.

GET https://freewebptojpg.com/mime/image/jpeg-xs.json Open JSON

Free to use

No auth required

CORS enabled

Use from any domain

Cached 24h

Cache-Control headers set

Frequently Asked Questions

What is the difference between JPEG 2000 and JPEG XS?

While both use wavelet transforms, JPEG 2000 focuses on high compression ratios and complex scalability for archiving and cinema. JPEG XS prioritizes ultra-low latency (fractions of a millisecond) and low hardware complexity, making it ideal for real-time live broadcasting, VR/AR, and video over IP.

What is the magic byte for a JPEG XS file?

A raw JPEG XS codestream begins with the Start of Codestream (SOC) marker, which is FF 10 in hex. When housed in an ISOBMFF container, it uses a standard 4-byte size followed by the 'ftyp' box and the major brand 'jxs ' (6A 78 73 20).

Are JPEG XS files supported in web browsers?

No. JPEG XS is a specialized format utilized almost exclusively in professional broadcast infrastructure, 5G video transport, and embedded hardware systems. It has no native support in consumer web browsers.