Every video file on your disk is compressed with a specific video codec. In 2026 you will run into three of them almost every day: H.264 (also written AVC), HEVC (H.265), and AV1. They do the same job at wildly different efficiency, with wildly different playback support, under wildly different licences. Picking the right one for the file you are about to make is a compatibility question first, an efficiency question second, and a licensing question a distant third for most people.

#The one-sentence version

Use H.264 unless you have a specific reason not to. It plays on literally every consumer device from the last fifteen years. HEVC saves you roughly 40% on file size at the same visual quality but only plays cleanly on Apple hardware, modern Android, and Windows 10+. AV1 saves you another 20-30% on top of HEVC and is finally hardware-decoded on new laptops, but it is still slow to encode and inconsistent to play on anything older than 2022.

#H.264: the safe default

H.264 shipped in 2003, is the most widely deployed video codec in history, and is what your phone, camera, screen recorder, and video editor default to unless you deliberately switch. Every operating system since Windows 7 and iOS 4 has a hardware decoder for it. Every browser plays it inside a <video> tag. Every social platform accepts it. Every video editor imports and exports it without an "install additional codec" prompt.

Its efficiency is nothing special by 2026 standards. A one-hour 1080p 30 fps clip at "visually transparent" quality lands around 3-4 GB in H.264. The same clip in HEVC lands around 1.8-2.4 GB. The same clip in AV1 lands around 1.3-1.7 GB. If storage or bandwidth matters, H.264 is the wasteful pick.

Its licensing is patent-encumbered but has been paid down at the vendor level for so long that consumers never see a bill. Every OS ships a decoder; the patent pool licence is baked into the OS licence.

#HEVC (H.265): the compression winner with playback caveats

HEVC shipped in 2013 and delivers roughly 40-50% better compression than H.264 at the same visual quality. This is why every iPhone since the iPhone 7 records HEVC by default when the "High Efficiency" camera setting is on, and why Apple TV, Netflix 4K, and most 4K Blu-rays use it. When it plays, it plays as well as H.264. When it does not, the failure is usually silent - a black frame or a "video format not supported" dialog.

Playback compatibility today:

  • Native and reliable: every iOS 11+ device, every macOS 10.13+ Mac, every Apple TV 4K, most 2019+ Android phones with hardware decode, Windows 10 (with a $0.99 store extension) and Windows 11 (bundled), every current smart TV.
  • Inconsistent: older Android phones, older smart TVs, Chromecast (the third-gen and later work; older ones do not), some in-browser video players (Safari plays HEVC in a video tag; Chrome and Firefox do not by default).
  • Unreliable: pre-2018 Android, pre-2017 smart TVs, most in-browser use outside Safari.

Its licensing is the reason HEVC never became a browser default. There are two competing patent pools (MPEG-LA and HEVC Advance) with overlapping and unclear terms, and enough small-vendor holders to make blanket-licensing a legal minefield. Chrome and Firefox chose to skip HEVC in-browser entirely for many years and only started shipping decoders when hardware decode was already common. Encoding HEVC also touches those patent pools - this is why libx265 is GPL and why Wave does not bundle it.

#AV1: royalty-free, slowly catching up

AV1 shipped in 2018 as the Alliance for Open Media's answer to the HEVC licensing mess. It is genuinely royalty-free, delivers another 20-30% compression improvement over HEVC, and is the format YouTube, Netflix, and Meta are moving toward for their high-volume delivery paths. The catch is that software AV1 encoding is famously slow - the reference encoder libaom-av1 runs at fractions of realtime on a laptop, and even the faster SVT-AV1 fork is measured in seconds per frame at high quality. Hardware AV1 encoders shipped in Intel Arc (2022), NVIDIA Ada (2022), and Apple Silicon M3 (2023).

Playback compatibility today:

  • Native and hardware-decoded: Chrome / Edge on Windows and macOS, Firefox on all desktops, iPhone 15 Pro and later, iPad M-series, Samsung Galaxy S23+, Pixel 6+, Windows 11 laptops with Intel 11th-gen or newer, most current smart TVs.
  • Software-decoded (works but drains battery): older Chrome / Firefox installs, older Android.
  • Not supported: Safari on Intel Macs, older Apple TV, most Chromecasts before the current gen, older smart TVs.

The near-term reality: AV1 is where HEVC was around 2016 - excellent when it works, still a compatibility gamble for anything you're distributing.

#Real numbers: same clip, three codecs

A 5-minute 1080p 30 fps clip of typical camera content, encoded at "visually transparent" quality:

  • H.264 High profile: around 380 MB. Encodes in real-time or faster on any modern CPU. Plays everywhere.
  • HEVC Main profile: around 230 MB (about 40% smaller). Encodes at 2-5x realtime with hardware, 0.3-0.5x realtime with software x265. Plays on Apple + Windows + modern Android.
  • AV1 Main profile: around 175 MB (about 25% smaller than HEVC). Encodes at 3-10x realtime with hardware, 0.05-0.2x realtime with SVT-AV1 software. Plays on modern browsers + iPhone 15 Pro+ + Windows 11 + modern smart TVs.

The savings look larger on 4K than 1080p because the codec differences scale with pixel count. A 4K HDR file that lands at 15 GB in H.264 lands around 8 GB in HEVC and 6 GB in AV1.

#What Wave picks and why

Wave outputs H.264 whenever the browser has a WebCodecs H.264 encoder (Chrome, Edge, Safari 16.4+, most Chromium mobile browsers). That decision is based on: (a) H.264 plays literally everywhere, which fits Wave's "convert to MP4 that just works" promise, and (b) the browser's built-in H.264 encoder is hardware-accelerated on most machines, so it is fast enough to be practical for browser-side conversion. When the source is HDR / 10-bit and the browser has a WebCodecs HEVC encoder, Wave uses HEVC Main 10 to preserve the colour depth. AV1 encoding through WebCodecs is technically possible but too slow to be a good in-browser experience today; Wave does not use it yet.

For the small share of browsers without WebCodecs H.264, Wave falls back to MPEG-4 Part 2 (via the LGPL wasm ffmpeg core) because that is what the LGPL build ships. That codec is a shade less efficient than H.264 but plays essentially everywhere H.264 does.

Wave does not bundle libx264 or libx265 - both are GPL, and bundling them would pull the whole distribution under GPL. See the local-conversion article for why licence cleanliness matters when the encoder ships to the browser.

#Which one should YOU pick?

Sending to a specific person or platform: H.264 in an MP4. It plays for them, whatever they are on.

Archiving your own footage on your own storage: HEVC. You save 40% on disk, and everything you own can play it back.

Streaming to a paying audience at scale (YouTube-style, Netflix-style): AV1 for the highest quality tiers, HEVC as a fallback, H.264 as the compatibility floor. This is a real ladder of adaptive streams, not one file.

Embedding video in a web page: H.264 in MP4 as the primary source, MP4 with HEVC as an optional higher-quality alternative for Safari. AV1 in WebM as an experimental modern tier for capable browsers. See MP4 vs MKV for the container side of the decision.

In every case, the codec choice is downstream of the compatibility question. Pick the widest-supported codec that meets your quality needs, not the most efficient codec on paper.