What Is the AV1 Codec? A Plain-English Explainer (2026)
What Is the AV1 Codec?
The AV1 codec is a modern, royalty-free video compression standard designed to shrink video files dramatically while staying completely free to use. If you've streamed a 4K video on YouTube or Netflix in the last few years, there's a good chance it was delivered to you as AV1 — even if you never noticed. It's one of the most consequential pieces of video technology of the last decade, and yet most people have no idea it exists.
This guide is a plain-English explainer of what AV1 is, who built it, why it exists, and how the encoder actually works. We'll keep the jargon light and the concepts accessible. If you want a head-to-head battle between codecs, we have dedicated comparisons for AV1 vs H.265 and AV1 vs H.264 — this article focuses on understanding AV1 itself.
If you're new to the topic entirely, it helps to first understand what a video codec is and what video encoding actually does. A codec is the method used to compress and decompress video; encoding is the act of applying it. AV1 is one specific, very good method.
AV1 at a Glance
| Property | Detail |
|---|---|
| Full name | AOMedia Video 1 (AV1) |
| Created by | Alliance for Open Media (AOM) |
| Released | 2018 (version 1.0) |
| Type | Open-source, royalty-free video codec |
| Compression vs H.264 | ~50% smaller files at equal quality |
| Compression vs H.265 (HEVC) | ~30% or more smaller |
| Max resolution | 8K and beyond |
| HDR | Yes (HDR10, Dolby Vision) |
| Encoders | libaom (reference), SVT-AV1, rav1e |
| Mac support | Hardware decode on Apple Silicon; no hardware encode |
| Used by | YouTube, Netflix, Vimeo, Meta, Twitch |
Who Made AV1, and Why?
AV1 was developed by the Alliance for Open Media (AOM), a consortium founded in 2015. Its founding members read like a who's who of the technology industry: Google, Mozilla, Microsoft, Apple, Amazon, Netflix, Meta, Intel, and others. Version 1.0 of the AV1 bitstream was frozen and released in 2018.
The motivation behind AV1 was equal parts technical and economic. The dominant efficient codec at the time, H.265 (HEVC), was technically excellent but tangled in a licensing mess. HEVC's patents were spread across multiple patent pools with inconsistent, expensive, and sometimes contradictory royalty terms. For companies delivering billions of minutes of video per day — or building web browsers that need to decode video for free — those royalties and legal uncertainties were a serious problem.
The industry's answer was to build a next-generation codec that no one would ever have to pay to use. That single decision — royalty-free — is the reason AV1 exists and the reason it spread so quickly across the web. AOM members committed to not asserting patents against AV1 implementations, which means any developer, company, or individual can encode and decode AV1 without licensing fees.
Technically, AV1 didn't start from a blank page. It merged the best ideas from three separate open-source codec projects: Google's VP9, Mozilla's Daala, and Cisco's Thor. The result is a codec with a much larger toolbox than anything that came before it.
How the AV1 Codec Works (Without the Math)
Every modern video codec works on the same basic principle: instead of storing every pixel of every frame, it stores predictions and the small differences between what it predicted and what actually happened. AV1 is exceptionally good at making those predictions. Here are the key tools that make it powerful, explained accessibly.
Compound Prediction
When a codec compresses a frame, it tries to guess what each block of pixels looks like by referencing other frames — a technique called prediction. Older codecs pick one reference. AV1 can blend two predictions together ("compound prediction"), averaging a guess from an earlier frame with a guess from a later one. This produces a more accurate starting point, which means smaller correction data and a smaller file. It's especially effective for smooth motion and fades.
Palette Coding
Some video content isn't camera footage — it's screen recordings, animation, slides, or user-interface walkthroughs, where large areas use just a handful of exact colors. AV1's palette coding recognizes these regions and stores a small color palette plus an index for each pixel, rather than describing the color from scratch. For screen content and animation, this is enormously efficient, which is why the AV1 codec shines on tutorial videos and app demos.
CDEF (Constrained Directional Enhancement Filter)
Aggressive compression creates artifacts — the faint "ringing" halos and blocky edges you sometimes see around sharp lines in a heavily compressed video. AV1 applies a smart cleanup filter called CDEF that detects the direction of edges in the image and smooths away those artifacts without blurring the real detail. The result is cleaner-looking video at lower bitrates.
Tile-Based Parallelism
A single video frame can be enormous, and processing it end-to-end is slow. AV1 can split each frame into independent tiles that can be encoded and decoded in parallel across multiple CPU cores. This is what makes real-time AV1 decoding practical on modern devices, and it's central to speeding up the notoriously slow encoding process.
These four are just the headline features. AV1 has dozens of additional tools, and the encoder's job is to decide, block by block, which combination produces the best quality for the fewest bits. That decision-making is exactly what makes AV1 so effective — and, as we'll see, so slow to encode.
How Efficient Is AV1?
Compression efficiency is AV1's headline achievement, and independent testing from Netflix, Meta, and academic researchers backs it up. At the same visual quality:
- AV1 produces files roughly 50% smaller than H.264, the old web standard.
- AV1 produces files roughly 30% or more smaller than H.265 (HEVC), the previous efficiency leader.
To put that in concrete terms: a 10-minute 4K clip that lands around 1.5 GB in HEVC might come in near 1 GB in AV1 at equivalent perceived quality. Multiply that across a streaming service's entire catalog and billions of daily views, and the bandwidth savings become staggering.
The gap depends on the content. AV1's advantage is largest on animation and screen recordings — where palette coding does heavy lifting — and narrows somewhat on chaotic, high-motion footage like sports. But across the board, the AV1 codec sets the current standard for squeezing quality into a small file. For a full breakdown against the previous champion, see our AV1 vs H.265 comparison.
The Catch: AV1 Encoding Is Slow
If AV1 is so efficient, why isn't everything encoded in it already? The answer is encoding speed. All those clever tools give the encoder an enormous number of decisions to make for every block of every frame, and evaluating them takes serious computing time.
The reference encoder, libaom-av1, is thorough but brutally slow — a high-quality software encode can run 10 to 50 times slower than an equivalent HEVC encode on the same machine. For a long time, this made AV1 impractical for anything but large companies with data centers full of encoding hardware.
Two developments have changed that:
- SVT-AV1 — Intel's Scalable Video Technology encoder for AV1 is dramatically faster than libaom thanks to heavy parallelism and smart engineering optimizations. It's now integrated into FFmpeg and has become the go-to AV1 encoder for practical software encoding. At its middle speed presets it approaches usable throughput while still beating HEVC on file size.
- Hardware AV1 encoders — dedicated silicon that encodes AV1 at real-time or faster speeds, which we'll cover next.
SVT-AV1 is what most modern pipelines use.
AV1 Hardware Support: Decode vs Encode
This is the single most misunderstood part of AV1, so it's worth stating clearly: decoding and encoding are separate capabilities, and a device can support one without the other.
Decoding (playing AV1 video) is now widespread:
- Apple Silicon Macs (M1 and later) — hardware AV1 decode
- iPhone 15 Pro and later — hardware AV1 decode
- NVIDIA RTX 30-series and later — hardware AV1 decode
- Intel Arc and recent integrated graphics — hardware AV1 decode
- Many 2021+ Android flagships (Snapdragon 888+, recent MediaTek Dimensity)
Encoding (creating AV1 video) in hardware is far rarer:
- NVIDIA RTX 40-series GPUs — hardware AV1 encode
- Intel Arc GPUs and newer Intel integrated graphics — hardware AV1 encode
- Apple Silicon — decode only, no hardware AV1 encode as of the M4 generation
That last point matters for anyone working on a Mac. Your M-series Mac can play AV1 beautifully, but it cannot encode AV1 in hardware — so any AV1 file you create on a Mac must go through slow software encoding on the CPU. We'll come back to what that means practically.
Browser and Platform Support
On the web, AV1 has surprisingly broad reach:
- Chrome — full support since 2018
- Firefox — full support since 2019
- Edge — full support (Chromium-based)
- Safari — supported on Apple Silicon with hardware AV1 decode (macOS 13+, iOS 17+)
The irony is that AV1 achieved wider guaranteed browser support than HEVC ever did, precisely because it's royalty-free — browser vendors could implement it without licensing headaches. That's the whole reason the Alliance for Open Media formed in the first place.
Where is AV1 actually used today? YouTube serves AV1 to capable devices to cut CDN costs. Netflix uses AV1 for streaming, including on mobile where bandwidth savings extend battery and data plans. Vimeo, Meta, and Twitch have all adopted it. For large-scale streaming, AV1 has effectively become the modern default, gradually displacing H.264.
Using AV1 on a Mac, Practically
Here's the honest, practical picture for Mac users in 2026.
Playback: On an Apple Silicon Mac, AV1 just works. QuickTime, Safari, and most modern video apps play AV1 with hardware decode acceleration — smooth and battery-efficient. Intel Macs play AV1 too, but in software, which spins up the CPU.
Encoding: This is where reality bites. Because Apple Silicon has no hardware AV1 encoder, creating AV1 files on a Mac means software encoding — slow and CPU-intensive, even with SVT-AV1. For a quick clip that's fine; for a large batch of long videos, it can take hours with the fans running.
That's why, for day-to-day video compression on a Mac, most people are better served by HEVC (H.265), which every M-series Mac can encode in hardware at near-real-time speeds. HEVC isn't quite as efficient as AV1, but the speed difference on Apple hardware is enormous. To understand that codec in depth, see our HEVC codec explained guide.
How Compresto Handles Codecs on macOS
Compresto is built specifically for the Mac compression workflow, and it makes the pragmatic choice based on the hardware reality described above. Because Apple Silicon provides hardware AV1 decode but not encode, Compresto uses hardware-accelerated HEVC via Apple's VideoToolbox framework for its video compression.
What that means in practice: on an M-series Mac, the dedicated media engine handles the encoding — not the CPU — so a 10-minute 4K video can be compressed to a file roughly 40–50% smaller in just a few minutes, without the fans spinning up or your other work slowing down. You get excellent compression at speeds that software AV1 encoding simply cannot match on Apple hardware today.
This is deliberately the opposite of forcing slow software AV1 encoding onto a chip that can't accelerate it. As Apple adds hardware AV1 encode support to future Apple Silicon, AV1 output becomes a natural addition — the decode side is already there. Until that day, hardware HEVC is the fast, high-quality choice for Mac video compression.
Compresto also handles images, GIFs, and PDFs, and can process entire folders in a batch. If you want the technical background on the encoding step itself, our explainer on what video encoding does pairs well with this article.
Where AV1 Fits Among Other Codecs
AV1 doesn't exist in a vacuum. It's the current open-source efficiency leader, but the landscape has several players worth knowing:
- H.264 — the aging universal standard; plays everywhere but is the least efficient. See AV1 vs H.264.
- H.265 (HEVC) — the previous efficiency leader, still dominant for Apple-ecosystem capture and fast hardware encoding. See AV1 vs H.265.
- H.266 (VVC) — the newest ITU standard, roughly matching AV1's efficiency but carrying HEVC-style licensing complexity that has slowed its adoption. Learn more in what H.266 (VVC) is.
- ProRes — a completely different beast: a high-bitrate editing codec built for quality and fast scrubbing, not small files. See what ProRes is.
The takeaway: AV1 is the codec to reach for when small file size and free licensing matter most, especially for web delivery. For fast local compression on a Mac, HEVC still wins on speed.
FAQ: The AV1 Codec
Q: What is the AV1 codec in simple terms?
AV1 is a modern, open-source video codec that compresses video into much smaller files than older codecs like H.264, without any royalty fees. Released by the Alliance for Open Media in 2018, it's used by YouTube, Netflix, and most major streaming platforms to reduce bandwidth while keeping quality high.
Q: Is AV1 better than H.264 and H.265?
In pure compression efficiency, yes. AV1 files are roughly 50% smaller than H.264 and 30% or more smaller than H.265 (HEVC) at the same quality. The tradeoff is encoding speed: AV1 is far slower to encode in software and has narrower hardware encode support than either older codec.
Q: Can my Mac play AV1 video?
If it has Apple Silicon (M1 or later), yes — every M-series Mac includes a hardware AV1 decoder, so playback in QuickTime and Safari is smooth and battery-efficient on macOS 13 Ventura and later. Intel Macs decode AV1 in software, which works but uses more CPU.
Q: Why is AV1 encoding so slow?
AV1's large toolbox of compression techniques gives the encoder far more decisions to make per frame, which is computationally expensive. The reference libaom encoder can run 10–50x slower than HEVC. Intel's SVT-AV1 narrows the gap, and hardware encoders make it fast — but Apple Silicon has no AV1 hardware encoder yet.
Q: What hardware can encode AV1?
As of 2026, hardware AV1 encoding lives on NVIDIA RTX 40-series GPUs, Intel Arc GPUs, and newer Intel integrated graphics. Apple Silicon supports hardware AV1 decode but not encode, so Mac apps still rely on HEVC via VideoToolbox for fast, hardware-accelerated video compression.
Want to compress video on your Mac right now with fast, hardware-accelerated encoding? Download Compresto for Mac and shrink your video library with HEVC via VideoToolbox — quick encodes, dramatically smaller files, and no quality loss.