How to Open a JXL File on Windows
On Windows 11 24H2 or later, a free Microsoft extension makes a .jxl behave like any other photo: thumbnails in File Explorer, opens in Photos. On Windows 10 that extension won't install, so you need a program that brings its own decoder. Both routes, checked on a real PC in October 2026.
by Robert Castillo · Published
The short answer
Whether a .jxl opens on your PC comes down to one number: your Windows build. Microsoft publishes a free JPEG XL Image Extension in the Microsoft Store, and once it's installed File Explorer draws thumbnails and the Photos app opens the file like any JPEG. The catch is that the Store listing requires build 26100, which is Windows 11 version 24H2, or newer. Windows 10 and older Windows 11 releases can't install it at all.
Nothing installs it for you, either. Our test PC, a Windows 11 Pro 24H2 machine fully updated to build 26100.9457 in October 2026, still couldn't decode a single .jxl. Windows Update doesn't bring the decoder; the Store does.
If you can't or don't want to install anything, three routes need no setup: Google Chrome, which decodes JPEG XL by default since version 155, Firefox, which does since version 158, and the viewer on this site, which works in any browser and never uploads the file.
| Your PC | What to use, and what you get |
|---|---|
| Windows 11 24H2 or 25H2 | Microsoft's free JPEG XL Image Extension. You get thumbnails in File Explorer, and the file opens in an up-to-date Photos app. |
| Windows 11 23H2 or older | Update Windows if you can; otherwise a viewer such as XnView MP. Thumbnails only with jxl-winthumb, and Photos won't open it. |
| Windows 10 | XnView MP, IrfanView, ImageGlass or Paint.NET. Thumbnails only with jxl-winthumb, and Photos won't open it. |
| Any PC, nothing installed | Chrome 155 or later, Firefox 158 or later, or this site's viewer. You see the picture, but File Explorer and Photos stay as they were. |
Windows 11 24H2 and later: install Microsoft's extension
1. Check your build
Press Win + R, type winver and press Enter. You need «Version 24H2» (OS build 26100.xxxx) or «Version 25H2» (OS build 26200.xxxx). Anything lower and the Store will refuse the install.
2. Get «JPEG XL Image Extension»
Open its Microsoft Store page (product ID 9MZPRTH5C0TB) and click Get. The publisher should read «Microsoft Corporation» and the price «Free». From a terminal, winget install --id 9MZPRTH5C0TB --source msstore does the same job.
3. Reopen File Explorer and Photos
Close any Explorer windows and the Photos app, then open them again. Signing out and back in is the surest way to get thumbnails immediately; otherwise they fill in as Explorer rebuilds its cache.
4. Make sure Photos is recent
Microsoft added JXL support to Photos in version 2025.11030.20006.0, a version that reached Windows Insiders in March 2025. If Photos still refuses the file, open the Store, go to Library → Get updates, and check the version in Photos under Settings → About. Our test PC had 2026.11090.22001.0.
The extension isn't an app: nothing appears in the Start menu and there's nothing to configure. Microsoft describes it as a plug-in that «Windows apps, such as Microsoft Photos and File Explorer» use to decode JPEG XL, built on the open-source libjxl library. The listing also mentions setting a .jxl as your desktop background and opening one in Windows Media Player Legacy. It's about 17 MB, runs on both x64 and ARM64 PCs, and its Store page shows the last update on 12 August 2026.
What we found on a 24H2 PC without the extension
Before installing anything, we looked at how a fully updated Windows 11 24H2 PC handles a .jxl on its own. Windows already knows the format exists. The registry maps .jxl to image/jxl and classes it as an image, and the Windows Imaging Component lists a «Microsoft JPEG XL Decoder» inside the system's own windowscodecs.dll, complete with the two byte signatures a JPEG XL file can start with.
It just can't decode anything. Asking Windows to open our two test files, one lossy and one repacked from a JPEG, failed both times with error 0x88982F8B, which Windows defines as a component that failed to initialise. A random non-image file fails differently, with 0x88982F50, «component not found». In plain terms: 24H2 has the slot for a JPEG XL decoder, and the Store extension is what fills it.
That explains a symptom people describe as «Windows half-recognises it»: File Explorer files the photo under a generic JXL type with no dimensions and no preview, even though it clearly knows it's dealing with a picture.
Windows 10 and older Windows 11: viewers with their own decoder
Below build 26100 the Microsoft extension is off the table, so the job falls to programs that ship their own JPEG XL decoder. These are the ones we'd point a friend to in October 2026, with the version current on each project's own site:
| Program | Cost and what to know |
|---|---|
| XnView MP 1.12.2 | Free for private use. Opens .jxl out of the box and can batch-convert a whole folder to JPG or PNG. |
| IrfanView 4.76 | Free for non-commercial use. Needs the separate PlugIns pack (4.76), whose JPEG_XL plugin reads and writes the format. Don't mix bitness: 64-bit plugins for 64-bit IrfanView. |
| ImageGlass 10.0.6 | Classic edition free (GPLv3). Opens and saves .jxl, though its own format list says not animated ones. Needs Windows 10 version 1809 or later. |
| Paint.NET 5.1.12 | Free from its own site, paid in the Store. JPEG XL built in since version 5.1.5 (March 2025). Needs Windows 10 21H2 or later and an x64 CPU with AVX2, or ARM64. |
| Google Chrome 155+ | Free. Decodes JPEG XL by default: drag the file onto a window. Runs on Windows 10 or later. |
| Firefox 158+ | Free. Shows JPEG XL by default since version 158, released on 13 October 2026. |
If the file arrived as a one-off, installing a program just to look at it is overkill: open it in this tab or turn it into a JPG. Neither uploads the file anywhere; the decoding runs on your own PC.
Thumbnails on Windows 10: jxl-winthumb
Viewers open the file, but File Explorer will keep showing blank icons. The open-source project jxl-winthumb fixes that by registering a JPEG XL decoder with the Windows Imaging Component, which Explorer uses for thumbnails and the preview pane. Its latest build, 0.2.12 from 30 August 2025, is based on version 0.12.4 of the jxl-oxide decoder.
1. Download the right DLL
From the project's Releases page, take jxl_winthumb_x86_64.dll for a normal 64-bit PC, jxl_winthumb_aarch64.dll for an ARM laptop, or jxl_winthumb_i686.dll for 32-bit Windows.
2. Register it as administrator
Move the DLL to a permanent folder first: Windows loads it from wherever you register it, so if it's later deleted from Downloads the thumbnails stop working. Then open Terminal or Command Prompt as administrator, change to that folder and run regsvr32 jxl_winthumb_x86_64.dll (with your file's name). A dialog confirms it worked.
3. Restart File Explorer
Sign out and back in, or restart «Windows Explorer» from Task Manager. Thumbnails appear as you reopen folders.
4. To remove it later
Run regsvr32 /u followed by the same file name from an administrator prompt, restart Explorer, and only then delete the DLL.
Three things to know before installing it. All 33 of its releases are flagged as pre-releases on GitHub. It does nothing for the Photos app: its author explains that Photos doesn't load third-party decoders and there's no public way to plug one in. And its issue tracker has open reports worth reading before you install, including HDR images whose thumbnails aren't tone-mapped, crashes on processors without AVX2, and one Explorer crash on 24H2.
Programs that use the Windows Imaging Component directly, such as the old Windows Photo Viewer where it's still enabled, can open .jxl through it too. If you're on 24H2 or later, skip it and use Microsoft's extension instead; there's no point running two decoders for the same format.
Browsers: Chrome and Firefox yes, Edge no
Google announced on 6 October 2026 that Chrome ships JPEG XL decoding «starting from Chrome 155», using a memory-safe Rust decoder called jxl-rs. In Chromium's source the change is easy to see: the JPEG XL feature is disabled by default in Chrome 145 and enabled by default from 155.
We checked it on our Windows 11 PC with Chrome 155.0.8059.40 and a brand-new profile, no flags touched: both test images decoded at full size, and opening a .jxl directly shows it in Chrome's own image view, titled with its dimensions. So on Windows 10 or 11 you can drag a .jxl onto a Chrome window, or right-click it and choose Open with → Choose another app → Google Chrome. If Chrome isn't in the list, use Choose an app on your PC and pick chrome.exe.
Microsoft Edge 155, released on 8 October 2026 on the same Chromium version, doesn't. Its web platform release notes don't mention JPEG XL, and in our test Edge 155.0.4283.45 failed both images even with the feature forced on from the command line; the feature's name doesn't appear anywhere in Edge's main library, so the decoder simply isn't in this build. Opening a .jxl in Edge just downloaded it.
Firefox 158, released on 13 October 2026, shows JPEG XL by default as well; which Firefox versions and forks have it is covered here. Brave 1.97.56 and later show it too (we tested 1.97.57). For Opera, Vivaldi or anything else, it's quicker to test your browser than to guess.
When it still won't open: symptoms and fixes
| What you see | Cause and fix |
|---|---|
| The Store won't install the extension, or says it won't work on this device | Your build is below 26100: Windows 10, or Windows 11 23H2 and earlier. Update to 24H2 or 25H2 if your PC qualifies; otherwise use one of the viewers above. |
| Extension installed, but File Explorer still shows plain icons | Explorer hasn't reloaded, the thumbnail cache is stale, or thumbnails are switched off. Sign out and in. Run Disk Cleanup and tick «Thumbnails». In File Explorer Options → View, untick «Always show icons, never thumbnails», and use Medium icons or larger. |
| Photos says it can't open the file | Photos is older than 2025.11030.20006.0, or the extension isn't actually installed. In the Store, use Library → Get updates, and check the extension is listed in your Library as installed. |
| The picture is black, very dark or washed out | Usually an HDR or high-bit-depth image reaching a decoder that doesn't tone-map it; open jxl-winthumb reports describe exactly this. Open it in another program to see whether the file itself is fine. With libjxl's tools, jxlinfo prints «Transfer function: PQ» for an HDR file (how to use them). To share it, convert it to JPG or PNG. |
| Nothing opens it, not even XnView MP or the viewer here | It isn't really JPEG XL (a renamed file), or the download was cut short. A real .jxl starts with the bytes FF 0A or 00 00 00 0C 4A 58 4C 20, the two signatures Windows' own decoder registers. Download it again or ask for the original. |
| Edge downloads the file instead of showing it | Edge 155 doesn't include a JPEG XL decoder. Use Chrome 155 or later, Firefox 158 or later, or the viewer on this site. |