YouTube Video Quality and Codecs Explained: 360p to 8K, H.264 vs VP9 vs AV1

Pick a resolution on a downloader and you are also choosing a codec, a frame rate, and possibly an HDR format, whether you know it or not. YouTube stores each video in many versions, and the one you download determines how big the file is, what will play it, and how it looks. This guide explains the labels you see next to each download option in plain language, so you can pick the right one instead of the biggest one.

Quick answer

• 1080p MP4 (H.264) is the best default for almost everyone: full HD, plays on every device, and imports into every editor.
• 720p is enough for phones and for talking-head videos, at about half the size.
• 1440p, 4K, and 8K only exist on YouTube as VP9 or AV1. They look better on a large 4K screen and are worth it for footage you plan to keep, but they need a modern player and can be five to ten times bigger than 1080p.
• 60 fps matters for gaming, sports, and fast motion; for talks it just makes the file bigger.
• HDR only pays off on an HDR display. For compatibility, Y-Download prefers the SDR version.

Resolutions: what the "p" numbers mean

The number is the height of the picture in pixels, and the "p" stands for progressive scan. For a normal 16:9 video:

Vertical videos such as Shorts are labeled by their longer side, so a "1080p" Short is 1080×1920. A video can only be downloaded at the resolutions the uploader provided: if someone uploaded 720p footage, no 1080p version exists, and choosing it on YouTube would not have helped either.

Resolution is only half the story. YouTube compresses every stream heavily, so a sharp 1080p from a good camera can look better than blurry 4K upscaled from a phone. The 4K YouTube downloader page lists what is available for each video; when in doubt, compare 1080p and 4K on your own screen.

Codecs: H.264 vs VP9 vs AV1

A codec is the method used to compress the video. YouTube uses three, and which one you get depends mostly on the resolution.

H.264 (AVC)

The workhorse of online video since the mid-2000s. Every phone, computer, TV, game console, and editing program plays it, usually with hardware acceleration that keeps battery use low. YouTube provides H.264 up to 1080p, and Y-Download picks it whenever it is available, paired with AAC audio, because compatibility is what most people need. Its downside is efficiency: for the same visual quality it needs a bigger file than the newer codecs.

VP9

Google's open codec, used by YouTube since 2013 and the only option for 1440p and 4K on many videos. It is noticeably more efficient than H.264, commonly cited as 30 to 40 percent smaller at the same quality. Hardware decoding is common in phones and computers from about 2017 onward, and Chrome, Edge, Firefox, Android, and Windows play it natively. Apple's QuickTime Player does not, and the iPhone Photos app will not import it, which is why VLC is the usual answer on Apple devices.

AV1

The newest of the three, released in 2018 by the Alliance for Open Media (Google, Apple, Microsoft, Netflix, and others). It is more efficient again than VP9, and YouTube increasingly uses it for popular videos and for high resolutions. Hardware decoding arrived in chips from about 2020, and in Apple devices with the A17 Pro and M3 generation, so older hardware has to decode it in software, which can mean stutter at 4K. The YouTube to MP4 downloader shows the codec next to each resolution so there are no surprises.

Why you cannot get 4K in H.264

YouTube simply does not encode resolutions above 1080p in H.264; the bandwidth cost would be too high. Y-Download keeps the VP9 or AV1 stream exactly as YouTube serves it rather than re-encoding it, because re-encoding would take a long time and lose quality. If you need 4K H.264 for an editor, download the original and convert it locally with a free tool such as HandBrake.

Frame rate: 30 vs 60 fps

Most videos are 24, 25, or 30 frames per second. Gaming, sports, and some vlogs are uploaded at 50 or 60 fps, which YouTube offers as separate streams at 720p and above. Y-Download preserves 60 fps when the video has it. The higher frame rate increases the file size by roughly a third to a half at the same resolution, so choose it when motion smoothness matters and skip it for lectures.

HDR vs SDR

HDR (high dynamic range) videos carry brighter highlights and a wider range of colors, stored as 10-bit VP9 or AV1. On an HDR-capable phone, TV, or monitor with a player that understands it, the difference is real. On a standard display, or in a player that does not tone-map, HDR footage looks washed out and gray. Because most downloads end up on ordinary screens and in ordinary players, Y-Download prefers the SDR version of a video when both exist.

How big are the files?

File size depends on bitrate, which varies with content: a static slideshow compresses far better than confetti or fast camera motion. Rough guidelines for one minute of video including audio:

• 360p: 3 to 5 MB
• 720p: 8 to 20 MB
• 1080p: 15 to 40 MB (the upper end for 60 fps)
• 1440p: 40 to 80 MB
• 4K: 90 to 200 MB
• 8K: 300 MB and up

Y-Download shows an estimated size next to every option before you download, which beats any rule of thumb. The current limits are 4 GB per file and four hours per video.

Which quality should you pick?

• Phone or tablet: 720p or 1080p. On a six-inch screen you are unlikely to see the difference from 4K, and the file is a fraction of the size.
• Laptop or desktop monitor: 1080p, or 1440p if you have a QHD display and a player such as VLC.
• 4K TV: 4K if the TV or streaming box plays VP9 or AV1 from a file (most recent ones do); otherwise 1080p, which the TV will upscale well.
• Video editing: 1080p H.264 unless you genuinely need the extra resolution, in which case download 4K and convert it.
• Archiving something you care about: the highest resolution available, SDR, in its original codec.
• Slow or metered connection: 480p or 720p.

For audio-only needs, skip video entirely and use the MP3 or M4A options on the YouTube downloader instead.