AV1 vs HEVC for web delivery.
Let the viewer's device pick the codec.

A compression chart is a fair way to compare AV1 and HEVC on a platform that transcodes every upload: the platform picks what each viewer receives, so your choice only shapes the master it starts from. Here there is no transcode and no rendition ladder. One link serves one file. If that file is AV1 and the client opens it on a device MDN does not list for AV1 in Safari, nothing steps in with an HEVC copy. The compression advantage only counts if the file plays.

That is why this page starts from the documented support rather than from file sizes. If the real choice in front of you is HEVC against H.264, that argument lives on the H.265 vs H.264 client delivery guide and is not repeated here.

Read the two columns against each other and a pattern appears. On Apple devices, HEVC is the codec with the broad floor: MDN documents it for every device on macOS High Sierra or later, and Apple’s own HEVC support article sets iOS 11 and macOS High Sierra 10.13 as the minimum for working with HEVC media. AV1 on Apple is recent hardware only.

Everywhere else, HEVC carries the conditions. Chrome needs hardware support on Windows, Linux and ChromeOS. Edge on Windows needs hardware support and an extension installed from the Microsoft Store. Firefox on Windows can decode it in software only if the user pays for and installs an extension. MDN’s AV1 sentence, by contrast, says AV1 is supported in all browsers and puts its one limit on Safari. MDN adds that many mobile and desktop devices have AV1 hardware decoders, and calls AV1 a great choice for serving video on the web, with a fallback for earlier Apple devices. That fallback is the part a no-transcode host cannot supply for you.

MDN states that AV1 achieves higher data compression rates than VP9 and HEVC, and as much as 50 percent higher rates than AVC. For HEVC it says that, theoretically, HEVC can reach file sizes half those of AVC at comparable image quality. The Alliance for Open Media, which develops AV1, describes it as an open codec built for greater efficiency than previous codecs; that is the developer’s own description, not an independent measurement. Neither source gives a single AV1 to HEVC ratio, so this page does not print one.

On this host, what that efficiency buys is concrete and limited. Plans are priced by storage and seats, with no per-view or bandwidth overage charge, so a smaller file at the same quality uses less of your plan. It also asks less of the viewer’s connection, which matters more here than on a transcoding platform, because there is no lower rendition to drop to: a slow connection buffers rather than switching to a softer picture. Those are real gains. They are worth nothing on a device that cannot decode the file.

The practical line is the same for both codecs. A 10-bit 4:2:0 file is the ordinary web case: HEVC Main 10 or AV1 Main. Anything with 4:2:2 moves into a separate profile, HEVC Main 4:2:2 10 or AV1 Professional, and browser decoding for those is not documented by MDN. The HEVC 10-bit 4:2:2 browser playback guide goes through what each vendor does and does not publish. Keep the 4:2:2 file for the download and send 4:2:0 to the browser.

Licensing is not a reason to choose either one for a client link. MDN notes that HEVC is patent-covered, with licensing managed by Via LA, and that fees are charged to developers rather than to content producers and distributors. AOMedia describes AV1 as an open codec.

Whatever you pick, test before the real film goes out. Export a thirty-second clip of the actual grade in the codec you chose, upload it, and ask the client to open the link on the exact computer or phone they will review on. Ask for one of four answers: it plays, it is black with sound, it stutters, or it will not start. Two things to check first: which browser, and whether the machine is one MDN lists for that codec.

Our uploader runs a smaller version of that test for you. Before a file uploads, your browser tries to decode it locally, and if it cannot, you see a warning and can still choose to upload the original anyway. That checks your browser, not your client’s. A file that plays on your M3 laptop in AV1 tells you nothing about a client on an older Intel Mac.

MDN frames AV1 as a great choice for the web with a fallback for earlier Apple devices. A platform that encodes several versions of each upload and chooses per viewer can supply that fallback, and for a public audience on devices nobody can name, that is the better tool. The price is that the platform decides what each viewer sees, and it re-encodes your film to do it.

uncompressed.io is for the other case: a small number of viewers you chose, watching work whose picture is the deliverable, on machines you can ask about. For that viewer, one file in the codec their device documents support for, served without a second encode, is the point. Choose the codec by the device, test it once, and read more about what a no-re-encode host changes in video hosting that does not compress.