Why Your Operating System Refuses to Decode a File

A .heic photo or an .mp4 clip that refuses to open usually isn't damaged. It's compressed with HEVC, a video codec that charges a royalty per device it ships on, or with AAC, its audio counterpart, and whoever built your OS or browser decided that fee wasn't worth paying for everyone. Convert HEIC to JPG or MP4 to WebM and the licensing problem disappears along with the file's dependence on either codec.

What should you do about it right now?

• Convert the file, free and instant. HEIC to JPG or MP4 to WebM runs in your browser, nothing uploaded, and the result opens on whatever refused the original.
• Buy the missing codec, if you want the OS itself fixed. Windows sells its HEVC decoder for $0.99 through the Microsoft Store. It fixes that one PC and nothing else; see how to open HEIC files on Windows for the full walkthrough.
• Pick a royalty-free format going forward if you control what gets created. WebM, AV1 and Opus were built specifically so nobody has to have this problem.

Who owns the patents behind HEVC and AAC?

A handful of companies, split across two separate patent-pool administrators, and MP3 is the one format on this list that got old enough to stop mattering.

The two paid rows are not one number. Via Licensing Alliance's own published AAC rate runs from $0.98 down to $0.10 a unit depending on volume, with no free allowance at all. Its H.264 rate is gentler: nothing for the first 100,000 units a company ships each year, then $0.20 up to five million units, then $0.10 beyond that, capped at $9.75 million a year per company. HEVC costs more again: the same free first 100,000 units, then $0.30 or $0.20 a unit depending on region, capped at $30 million a year, under Video Codec Licensing's current rate table. Our own H.264, HEVC, VP9 and AV1 comparison covers what each codec buys you in exchange for that fee.

None of these rates land on you as a viewer. As MDN's own developer documentation puts it, HEVC's fees are "charged to developers rather than to content producers and distributors." The bill goes to whoever ships a decoder, which is exactly why some of them decline to.

Why does Windows charge $0.99 to open an HEVC file?

Because Microsoft ships more than 100,000 Windows PCs a year, so the free tier in HEVC's own license runs out almost immediately, and Microsoft chooses to pass that per-unit fee to whoever actually wants the decoder rather than build it into every copy of Windows. Search the Microsoft Store for "HEVC Video Extensions" and, as of August 2026, Microsoft's own listing still prices it at $0.99, unchanged since we checked it for our HEIC-specific post.

That $0.99 buys a license for one PC. It has nothing to do with your specific photo or video; it's the same royalty a manufacturer pays to ship a hardware decoder, just collected from you at install time instead of from Microsoft at the factory. Some PCs get it free because their manufacturer already paid on their behalf, but Microsoft's own listing gives no way to check which PCs qualify before you try installing it.

How to open HEIC files on Windows covers the free HEIF Image Extensions, the paid HEVC Video Extensions they depend on, and what converting costs you in file size and metadata instead.

Do all browsers support HEVC and AAC the same way?

No, and they split along the same line every time: a browser backed by a company large enough to just pay the royalty ships its own decoder, and one that isn't defers to whatever the operating system already has.

Apple pays HEVC's and AAC's royalties as part of building the hardware, so Safari never asks. AAC's smaller per-unit fee is cheap enough that Chrome licenses it directly and ships a real decoder inside the browser, on every platform. HEVC's fee is the one Chrome and Edge won't absorb: neither ships a software HEVC decoder at all, so playback only works where a chip on the device already does the decoding, which is guaranteed on macOS and Android and conditional everywhere else. Mozilla's own documentation states it plainly for AAC: "Firefox only supports AAC if support is provided by the operating system or an external library." Firefox took until version 134, in early 2025, to add even that much for HEVC on Windows, which tells you how long a small, patent-averse browser can hold out before giving in to the format everyone else already opens.

What are the royalty-free alternatives?

Every royalty-free codec on the market exists because someone deliberately built it to route around this exact problem. WebM's container accepts only VP8, VP9 or AV1 video with Vorbis or Opus audio, all four free to implement, which is the whole reason the format exists rather than an accident of history. Opus carries the same guarantee for audio and is the mandatory codec behind every WebRTC video call, so you've almost certainly decoded it today without a file extension in sight. MP3 got there by outliving its own patents rather than by design, and it's the one format nobody, including Windows, has ever needed a license to open.

What do you lose by converting instead of paying for the codec?

Whatever the new codec can't hold, and it's worth knowing before you commit to it. Converting HEIC to JPG drops HDR gain-map data and a Live Photo's paired video clip, covered in full in how to open HEIC files on Windows. Converting MP4 to WebM is a real re-encode, not the near-instant copy you get moving between MP4, MOV and MKV: our own container test found FFmpeg refuses outright to put H.264 video into a WebM file, so a WebM export always means decoding and recompressing the video, with the quality trade-off that implies for a low-bitrate source.

FileFlip's own conversion engine runs into this same wall converting MP4 to WebM. It tries a browser-native encoder first and falls back to a WebAssembly build of FFmpeg under the LGPL, and an LGPL build carries no license to write H.264 or H.265 output. Our own code states this plainly, in a note it shows on the conversion page the moment it applies: "the FFmpeg fallback is an LGPL build, so a re-encode produces MPEG-4 Part 2, VP8, VP9, or Theora rather than H.264 or H.265." That fallback never hits the same wall producing a WebM target, because VP9 was free to license from the start and is exactly what it writes.

What should you actually do with the file in your hand?

Convert it, for almost every case that isn't "I want Windows itself to open every future HEIC without a second thought." Convert HEIC to JPG or MP4 to WebM and the result opens on the machine in front of you immediately, with nothing bought and nothing installed. The conversion runs entirely in your browser: the file is never uploaded, there's no account, and nothing is stored on a server anywhere.

Paying Microsoft's $0.99 only makes sense if you're the person who keeps receiving other people's HEVC-encoded files and wants your own PC to open them natively from here on. Everyone downstream of you, anyone you send the file to, still hits the same wall unless they pay it too, which is exactly why converting is usually the less annoying answer even when you can afford the codec.

Common questions

Will HEVC and AAC licensing ever end the way MP3's did?

Eventually, once enough of the underlying patents expire, the same way MP3's did: its core patents ran roughly 20 years from filing before Technicolor and Fraunhofer let the program lapse in 2017. Dozens of companies hold pieces of the HEVC and AAC pools, filed across different years, so there's no single expiry date; the licence winds down patent by patent rather than all at once.

Why does my phone play HEVC fine but my PC doesn't?

Because your phone's manufacturer almost certainly paid HEVC's per-unit royalty as part of building the device, the same way Apple does for every iPhone and Mac. A Windows PC ships without that payment made on your behalf by default, which is the entire reason Microsoft charges you for the decoder separately after the fact.

Does converting to a royalty-free format always mean a quality hit?

Not automatically, but a codec swap between formats with different compression, like HEVC to VP9, is still a lossy re-encode, and the result depends on the bitrate and settings you give it. Our own H.264, HEVC, VP9 and AV1 measurements show AV1 and VP9 both beating H.264 at low bitrates and HEVC pulling back ahead at higher ones, so "royalty-free" and "worse" aren't the same claim.

Is it legal for me to just convert the file myself?

Yes. The royalties above apply to whoever builds and distributes encoder or decoder software, not to you watching a video or opening a photo. Converting a file you already have, on your own device, isn't a licensing event for you at all.

Convert between them

FileFlip converts HEIC to JPG and MP4 to WebM entirely in your browser, on WebAssembly builds of the same libraries covered above. Nothing is uploaded, there's no account, and no codec purchase is required on either end. The image converter and video converter cover every other pair FileFlip supports.

How we measured this

• Royalty rates: read directly from the current rate tables published by Via Licensing Alliance for AAC and AVC/H.264, and by Video Codec Licensing for HEVC/VVC, fetched directly rather than taken from a secondary summary. The HEVC page itself states the Access Advance acquisition took effect December 15, 2025.
• Microsoft Store price: read from the page's own structured data at apps.microsoft.com, which reports an offer price of $0.99 as of August 2026.
• Browser support: MDN's own compatibility notes for video codecs and audio codecs, read directly rather than through a caniuse-style summary, since those notes carry the per-platform version numbers this page quotes.
• FileFlip's own fallback behaviour: read from apps/nextjs/src/utils/convert/mediabunny.ts and the note text in apps/nextjs/src/utils/convert/pair-facts.ts, the same source that renders the message on the live MP4-to-WebM conversion page.
• Caveat: patent license rates are set by the pools themselves and can change; every figure here carries the date we checked it, and a reader converting a file six months from now should expect the codec's status, if not the exact cents-per-unit rate, to have held.