Video Codecs Explained: H.264, H.265, VP9, and AV1

So you just finished editing a video, you hit "Export," and suddenly you're staring at a dropdown menu with like fifteen codec options. H.264? H.265? VP9? AV1? Something called "MPEG-2" that sounds like it's from 1997 (because it is)?

Most people just pick whatever's default and move on. And honestly? That works fine most of the time. But if you've ever wondered why your 4K export is 12 GB, or why your video looks like mud after uploading to social media, the answer almost always comes back to codecs.

Wait, What Even Is a Codec?

A codec is just a method for compressing and decompressing video data. The word itself is a mashup of "coder" and "decoder." Think of it like a language — your video player needs to speak the same language as the file to play it back.

Raw video is absurdly large. One minute of uncompressed 1080p footage runs about 10-12 GB. Nobody wants that. So codecs squeeze the data down by throwing away information your eyes probably won't miss (lossy compression) or by finding clever patterns to store everything more efficiently (lossless compression).

And here's where it gets a bit confusing: a codec is not the same thing as a container format. MP4, MKV, WebM — those are containers. They're like boxes that hold the compressed video (and audio, and subtitles). The codec is what goes inside the box.

An MP4 file usually contains H.264 or H.265 video. A WebM file typically contains VP9 or AV1. Same idea, different packaging.

H.264 (AVC) — The Old Reliable

If codecs were cars, H.264 would be a Toyota Corolla. Not flashy. Not the newest. But it gets the job done everywhere, all the time, without complaints.

H.264 (also called AVC, or Advanced Video Coding) has been around since 2003. It's the most widely supported video codec in existence. Your phone plays it. Your smart TV plays it. That ancient laptop from 2012 plays it. Every browser, every streaming service, every video platform on the planet supports H.264.

The compression is decent but not amazing by modern standards. A typical 1080p movie encoded in H.264 lands around 1.5-4 GB depending on quality settings. That was impressive in 2005. In 2026, we can do better.

Use H.264 when:

• You need maximum compatibility (literally everything plays it)
• You're exporting for older devices or unknown playback environments
• Encoding speed matters more than file size
• You're uploading to platforms that will re-encode anyway (like YouTube)

If you need to convert a video to MP4 with H.264 for broad compatibility, KokoConvert's MP4 converter handles that directly in your browser.

H.265 (HEVC) — The Efficient Successor

H.265 — or HEVC (High Efficiency Video Coding) — arrived in 2013 as the official follow-up to H.264. The pitch was simple: same quality, half the file size. And it mostly delivered.

A 1080p movie that takes 3 GB in H.264 might only need 1.5 GB in H.265 at comparable visual quality. For 4K content, the savings are even more dramatic. This is why Apple went all-in on HEVC for iPhone video recordings years ago.

But H.265 has a problem that's plagued it since day one: licensing. The patent situation around HEVC is an absolute mess. Multiple patent pools, overlapping claims, and fees that vary depending on what you're doing with it. This scared off a lot of companies (Google notably refused to put it in Chrome for years) and slowed adoption significantly.

As of 2026, support is much better than it used to be. Most modern devices handle H.265 fine. But it's still not as universally supported as H.264, and encoding takes noticeably longer — sometimes 3-5x slower depending on your hardware.

Use H.265 when:

• File size is critical (limited storage, slow upload speeds)
• You're working with 4K or higher resolution content
• You know your audience has modern devices
• You're archiving footage and want to save disk space

VP9 — Google's Royalty-Free Answer

Google looked at the H.265 licensing nightmare and basically said "we'll make our own codec, thanks." VP9 launched in 2013 (same year as H.265) and was designed to be completely royalty-free.

Performance-wise, VP9 is roughly comparable to H.265. Some independent tests show H.265 winning slightly in compression efficiency; others show VP9 ahead. The differences are small enough that it mostly comes down to implementation and tuning.

The big deal with VP9 is YouTube. If you've watched any video on YouTube in the last several years, you've been watching VP9 (or AV1). Google uses it extensively for their platform because, well, they made it and they don't have to pay anyone licensing fees.

VP9 works in Chrome, Firefox, Edge, and most Android devices natively. Safari added support relatively late. Hardware decoding on older devices can be spotty — your CPU might have to do the heavy lifting, which means more battery drain on mobile.

Use VP9 when:

• You're targeting web playback and want good compression without licensing worries
• You're encoding for WebM containers specifically
• Your audience primarily uses Chrome or Firefox

Got a WebM file and need it in a more universal format? The WebM converter can handle that conversion without you installing anything.

AV1 — The New Kid That's Actually Really Good

AV1 is the codec everyone's excited about in 2026, and for good reason. It's developed by the Alliance for Open Media (whose members include Google, Apple, Mozilla, Netflix, Amazon, and basically every major tech company you can think of). It's royalty-free. And it's genuinely better at compression than everything that came before it.

How much better? Tests consistently show AV1 achieving 20-30% smaller files than H.265 or VP9 at equivalent quality. For streaming services handling petabytes of video, those savings are enormous. Netflix has been encoding their catalog in AV1 for a while now.

The catch? Encoding is painfully slow. Like, an order of magnitude slower than H.264. If you try to encode a full-length movie in AV1 on a regular laptop without hardware acceleration, you might be waiting hours. Hardware encoding support is improving quickly — Intel, AMD, and NVIDIA all have AV1 hardware encoders in their recent chips — but it's still not as fast as H.264 encoding.

Decoding (playback) is much less of an issue. Most devices sold after 2022-2023 can play AV1 just fine, and browsers have widely adopted it. But older hardware? No luck.

Use AV1 when:

• You want the best possible compression and don't mind slow encoding
• You're preparing content for modern streaming or web delivery
• Bandwidth costs or storage are a primary concern
• You know your audience has recent hardware

The Practical Comparison

Let's put some rough numbers on this. For a 10-minute 1080p video at similar visual quality:

• H.264: ~500 MB — fast to encode, plays everywhere
• H.265: ~275 MB — slower to encode, good modern support
• VP9: ~280 MB — comparable to H.265, royalty-free
• AV1: ~200 MB — smallest file, slowest encode, newest hardware needed

These numbers are approximate — actual results depend heavily on the source material, encoding settings, bitrate targets, and a dozen other variables. But it gives you a sense of the progression.

So Which One Should You Actually Use?

Here's the honest answer: for most people, H.264 is still the right choice. Not because it's the best — it isn't — but because compatibility trumps everything else unless you have a specific reason to care about file size.

If you're uploading to YouTube, TikTok, or Instagram? Use H.264. The platform is going to re-encode your video anyway, so sending them a clean H.264 file gives the best starting point. Uploading in H.265 or AV1 doesn't mean your viewers get better quality — the platform decides what they serve.

If you're hosting video yourself (your own website, a CDN) and bandwidth costs matter, then H.265 or AV1 start making real sense. Netflix didn't switch to AV1 for fun — they did it because serving billions of hours of video at 20-30% less bandwidth saves actual millions of dollars.

For archiving personal footage — family videos, travel recordings, that kind of thing — H.265 hits a nice sweet spot. Good compression, reasonable encoding speed, and you won't have compatibility issues five years from now.

And if you're a creator who records a lot of screen content or gameplay, sometimes the real bottleneck isn't the codec at all — it's the fact that you've got a 2 GB recording that needs to be smaller for sharing. That's where a video compressor saves you from re-encoding the whole thing manually.

One More Thing: Don't Re-encode Unnecessarily

Every time you re-encode a video with a lossy codec, you lose a tiny bit of quality. It's like making a photocopy of a photocopy. Once or twice is fine. Ten times and things start looking rough.

So if someone sends you an H.264 MP4 and you need it as a WebM for your website, that's a valid conversion. But don't convert your H.264 to H.265 and then to AV1 hoping each step makes it smaller and better. It doesn't work that way. Always go back to your highest-quality source when re-encoding.

When you do need to switch formats — say, converting an old AVI to something modern — KokoConvert's AVI converter does the job right in your browser without uploading to some random server.

What About the Future?

AV1 adoption is accelerating fast. Hardware support is now standard in new phones, laptops, and GPUs. Browser support is basically universal for modern versions. Give it another year or two and AV1 might become the new default the way H.264 has been for the last two decades.

There's also work happening on AV2 and VVC (H.266), the official successor to H.265. But those are still early. You don't need to think about them yet.

For now, just remember: H.264 for maximum compatibility, H.265 for a good balance of size and quality, VP9 for royalty-free web use, and AV1 when you want the smallest files and have the hardware to back it up. That's really all there is to it.