Last updated: August 29, 2026

IrfanView will not open HEIC files

IrfanView opens most photos, but a HEIC file triggers an error or a blank thumbnail even after you install the TOOLS plugin. The reason: IrfanView's own plugin page says HEIC support works only "with installed codecs/extensions", meaning the plugin still depends on Windows' own HEIF Image Extensions (free) and HEVC Video Extensions ($0.99).

Why doesn't the plugin pack alone fix it?

HEIC is a container, not one single technology. Apple's HEIC files wrap image data encoded with HEVC, the same H.265 video codec used for 4K video, inside a HEIF container originally designed for storing image sequences and metadata efficiently. Reading a HEIC file is really two jobs: parsing the HEIF container, then decoding the HEVC-compressed pixels inside it. Windows treats those as two separate codec responsibilities, which is exactly why two separate Microsoft Store extensions exist for something that looks, to a user, like a single file format.

IrfanView doesn't ship its own HEIC decoder. The TOOLS plugin pack, the add-on set that brings HEIC and AVIF support into IrfanView, hands the actual decoding off to whatever HEIF/HEVC codec Windows itself has installed, the same codec layer Windows Photos and File Explorer thumbnails use. IrfanView's plugin page spells this out directly: TOOLS "contains some additional functions/features for IrfanView (and some special formats, like: HEIC, AVIF; with installed codecs/extensions)". That last clause is the part almost nobody reads before installing: the plugin adds the capability to open HEIC, but the codec that actually decodes the image has to come from Windows, separately.

This is why a common troubleshooting path fails: someone installs the TOOLS plugin, HEIC still won't open, and they conclude IrfanView is broken. In practice the plugin worked exactly as advertised, it's the Windows-side codec that's missing. For the full range of options beyond IrfanView, including Mac, Android and web browsers, see how to open HEIC files everywhere else.

How do I install the TOOLS plugin pack correctly?

Download the plugin installer from IrfanView's own plugins page, not a third-party mirror. HEIC support has shipped in TOOLS since version 4.75.0, and an old or repackaged installer is a common way to end up with a half-working setup. IrfanView ships 32-bit and 64-bit builds, and the plugin installer bundles both; you pick the matching one for your IrfanView install during setup, not two separate downloads.

Match it to whichever IrfanView you actually have installed. Most current Windows PCs run the 64-bit build, but plenty of long-time IrfanView users are still on 32-bit for compatibility with older plugins, so check Help, About IrfanView before assuming. Installing the 64-bit plugin pack onto a 32-bit IrfanView, or the reverse, is silent: no error at install time, just HEIC files that refuse to open later.

After installing, confirm the plugin actually registered: open Help, Installed Plugins, inside IrfanView. If the HEIC-related entries aren't listed there, the plugin didn't load, usually because of a bitness mismatch or an installer that silently failed. Reinstalling the correct-bitness TOOLS pack, then checking this list again, is faster than guessing at codec problems next.

Which Windows codecs does it also need?

Two separate Microsoft Store extensions cover the two halves of a HEIC file: the container, and the compressed image data inside it. Microsoft's own HEIF Image Extensions listing states that "The HEVC Video Extensions package must be installed in order to view images stored in HEIF files", so the free HEIF extension alone does nothing without it. The HEVC Video Extensions listing confirms the price: $0.99, one time, no subscription. Windows does not include HEVC decoding out of the box; both extensions have to be installed manually, by design, because HEVC is covered by a patent pool that charges licensing fees per device.

A free version, "HEVC Video Extensions from Device Manufacturer," exists for PCs whose maker pre-licensed HEVC, but it's OEM-locked and inconsistent across Windows versions, worth trying, not worth relying on.

Still not opening? Check these

Bitness mismatch.IrfanView's own support forum has a documented case of exactly this: a user running 32-bit IrfanView installed every HEIC-related codec available, HEIF Image Extensions, a standalone HEIC codec, even CopyTrans HEIC, and still couldn't open HEIC files, while the same photos opened fine in Windows' own Photos app. The fix in that thread was switching to 64-bit IrfanView. If you've installed every codec and it still fails, check your IrfanView bitness before anything else.

No reboot after installing the codecs. Windows doesn't always register a newly installed codec with processes that were already running. If you installed the HEIF or HEVC extensions while IrfanView, or Explorer, was already open, close both and restart Windows once.

A file that isn't really what it says. If one specific file fails to open while every other HEIC on the same PC opens fine, suspect the file itself before spending more time on codecs: it may be truncated, corrupted, or not a valid HEIC despite the extension. Try it in a different viewer, or in a browser converter, to see whether the file or the codec setup is at fault.

Still nothing? At that point convert the file rather than keep chasing codecs. Converting HEIC to JPG in a browser sidesteps every dependency described above, because the decoding happens inside the page itself rather than through Windows.

Batch converting inside IrfanView

If the plugin and codecs are working, IrfanView is a genuinely capable batch tool, worth knowing about even if you also convert single files elsewhere. IrfanView's own site describes File, Batch Conversion, for converting an entire folder in one pass. Press B, or open the File menu and choose Batch Conversion/Rename, point it at the folder of HEIC files, set the output format to JPG, and choose an output folder. Turning on Use Advanced Options in the same dialog adds resizing and renaming to the same pass, useful if the photos also need to be smaller before they go anywhere.

One honest caveat: batch conversion runs through the same codec chain as opening a single file. If HEIC won't open one at a time, batch conversion won't fix that, it will just fail on all of them at once, usually with one generic error per file rather than one clear message up front. Get single-file opening working first, per the sections above, before trusting a batch job on a folder you can't easily redo.

When would I rather not install anything?

Installing two codec packages and matching IrfanView's bitness is a reasonable one-time fix if you view HEIC files on this PC regularly. It's overkill for a one-off: someone emailed you three photos and you need them as JPG today.

For that, our HEIC to JPG converterskips the entire chain described above, no plugin, no Microsoft Store purchase, no bitness to match, because the decoding runs inside your browser rather than through Windows' own codecs, and the files never leave your device. It's honest to say what it doesn't replace, too: a converter website only fixes the files you actually convert, not File Explorer thumbnails or Windows Photos system-wide. For that, the codec installation above is still the real fix.

Need a lossless copy instead of JPG, for editing later? HEIC to PNG keeps every pixel. For background on HEIC as a format and why Windows doesn't support it out of the box, see what HEIC actually is and how it compares to JPEG. For the full picture on the browser converter itself, the HEIC converter hub is the place to start.

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