YouTube thumbnail sizes, compared
For every public video, YouTube generates a small set of thumbnail images and serves them from its image CDN at predictable addresses. There are exactly five standard sizes. They are not all equal, and — the part most downloaders don't tell you — they don't all exist for every video.
| File name | Pixels | Aspect | Exists when… | Best use |
|---|---|---|---|---|
maxresdefault.jpg | 1280 × 720 | 16:9 | The video was uploaded in HD, or the creator uploaded a custom 1280×720 thumbnail. Missing on many older and low-resolution uploads. | Anything full-width: blog headers, slides, print, design study. |
sddefault.jpg | 640 × 480 | 4:3 | The video exists in standard definition or better. On 16:9 videos the picture is letterboxed inside the 4:3 frame with black bars. | A dependable mid-size fallback when HD is absent. |
hqdefault.jpg | 480 × 360 | 4:3 | Essentially always — YouTube generates it for every public video, also letterboxed on widescreen videos. | Embeds, cards, article body images. |
mqdefault.jpg | 320 × 180 | 16:9 | Essentially always. Unlike HQ and SD, this one is a true 16:9 crop with no black bars. | Lists, sidebars, related-video widgets — the cleanest small size. |
default.jpg | 120 × 90 | 4:3 | Always — it is also the image YouTube substitutes when a larger size doesn't exist (see below). | Icons, avatars, placeholders in dense UIs. |
The placeholder trap
Ask YouTube's CDN for a size a video doesn't have and you do not get a 404. You get a real, loadable JPEG — 120×90 pixels, a centre frame-grab — wearing the requested size's address. Tools that only check "did an image come back?" will cheerfully save that 120×90 file and call it HD.
ThumbFetch instead compares the loaded image's actual pixel dimensions (naturalWidth) against the size it asked for. If a "1280×720" request comes back at 120 pixels wide, the card is labelled no HD thumbnail for this video and the download is disabled — because that is the truth about what YouTube has for that video. We verified the behaviour directly against the CDN: a 2005 upload's maxresdefault.jpg really is a 120×90 file, while its hqdefault.jpg is a genuine 480×360.
Which size should you download?
- Your own thumbnail, archived or reworked: maxresdefault, if it exists. It's the same resolution creators upload at.
- A blog post or article: maxresdefault for the hero; mqdefault (true 16:9) for in-text cards.
- Presentations: maxresdefault; fall back to sddefault and accept the letterbox bars, or crop them.
- Studying a competitor's design: maxresdefault — you need to read their text and see facial detail at full size.
- Just need a tiny visual reference: default.jpg is 120×90 and a couple of kilobytes.
Automatic frame-grabs: sizes 0–3
Separately from the five named sizes, YouTube also keeps four auto-generated stills from the video itself, named 0.jpg to 3.jpg (480×360). One of them — usually 0.jpg — doubles as the video's thumbnail when the creator never picked one. These are frames, not the designed thumbnail, so ThumbFetch's downloader focuses on the five named sizes above; if a video has no custom thumbnail, its named sizes already show that same frame anyway.
Ready to grab one? Back to the downloader →