In this article
After reading, you'll understand:
- What "SD" actually covers, and where the line to HD sits
- The resolutions that count as SD and their dimensions
- How SD compares to HD on sharpness and bandwidth
- Where SD still earns a place in a modern ladder
What is standard definition?
SD, standard definition, is the label for video below the HD threshold — anything under 720p. On the web it almost always means 480p at 854×480; the older 4:3 frame was 640×480, and 360p and 240p sit below as fallback tiers.
The term is a holdover from broadcast and DVD, when 480-line (NTSC) and 576-line (PAL) pictures were the norm. Everything above them became "high definition", and the two labels have stuck even though the numbers moved on.
SD in the resolution ladder
SD is the bottom of the ladder every modern platform still builds. The tier label maps to the numeric rungs like this:
| Label | Resolution | Tier | Pixels |
|---|---|---|---|
| 480p | 854×480 | SD | 409,920 |
| 720p | 1280×720 | HD | 921,600 |
| 1080p | 1920×1080 | Full HD | 2,073,600 |
| 2160p | 3840×2160 | 4K / UHD | 8,294,400 |
Everything at 720p and above is HD. SD is the tier below — 480p and the smaller fallbacks under it.
SD vs HD
The jump from SD to HD is the one viewers actually notice — 720p carries 2.25 times the pixels of 480p, and it is the first tier at which on-screen text stays crisp. The trade is data:
| SD (480p) | HD (720p) | |
|---|---|---|
| Dimensions | 854×480 | 1280×720 |
| Pixels per frame | 409,920 | 921,600 |
| Typical bitrate (H.264) | 1–2 Mbps | 2.5–4 Mbps |
| Data per hour | ≈450–900 MB | ≈1.1–1.8 GB |
| Screen text stays sharp | No | Yes |
For a fuller breakdown of the tier above, see HD (high definition).
Where SD still fits
Nobody targets SD as a delivery resolution any more, but it earns its keep as a rung in the ladder:
A sharp-enough picture that never stalls beats an HD stream that buffers every thirty seconds.
At roughly 450–900 MB an hour, SD is the difference between finishing a lesson and running out of allowance.
Adaptive players often open on an SD rendition and climb once the buffer is healthy, so playback begins sooner.
Where it fails is detail: screen recordings with code or spreadsheets are unreadable at SD, and no bitrate rescues them. For that content, 1080p is the floor.
What actually puts a viewer on SD
Nobody selects standard definition. It is what the ladder falls back to, and there are only a few reasons a viewer lands there.
Adaptive delivery drops to the rung the link sustains. On a metered or rural connection that is often 480p, and the alternative is not a sharper picture but a stalled one.
Archive footage, screen captures from old systems and re-encoded DVDs arrive at SD. Transcoding upward invents nothing; it only costs more to store and deliver.
Which is why removing SD from the ladder to look premium is a mistake worth naming: the viewers it affects are the ones with the worst connection, and what they lose is not sharpness but playback.
How Kinescope handles this
You never set a tier by hand. Transcoding builds the full ladder from your source — SD rungs included — and the adaptive player serves SD over the CDN only when a viewer's connection needs it, then climbs back up.
Read the Kinescope docsFrequently asked questions
What does SD mean in video?
SD stands for standard definition — video below the HD threshold, in practice 480p (854×480) or smaller. It is the tier one step under 720p HD.
What resolution is SD?
Most often 480p, which is 854×480 in widescreen 16:9 or 640×480 in the older 4:3 shape. 360p and 240p are also SD, but they are fallback tiers rather than a target.
What is the difference between SD and HD?
HD begins at 720p (1280×720); anything below is SD. HD has at least 2.25 times the pixels of 480p SD and needs roughly double the bitrate, but it is the first tier at which on-screen text stays sharp.
Is 480p SD or HD?
480p is SD. The HD line starts at 720p, so 480p sits one rung below it — the top of standard definition.
Is SD good enough for online video?
Only as a fallback. Talking-head footage survives SD, but anything with fine detail — screen recordings, text, dashboards — needs HD or Full HD. Ship 1080p as the primary rendition and let SD serve viewers whose connection demands it.
Do I need to make an SD version myself?
No. Kinescope transcodes every upload into a full ladder that includes SD rungs, and the adaptive player switches to them automatically when the connection cannot sustain a larger rendition.
Further reading
- Standard-definition television — Wikipedia — a vendor-neutral overview.
- HD (high definition) — the tier above.
- 480p and resolution — the numbers behind the label.
Read next
Best video hosting 2026: how to pick the platform that's right for you
Most video hosting lists treat the market like a leaderboard. This guide looks at what actually shapes the choice: what the host…
Read →Encoding480p
Standard-definition video, 480 pixels tall — 854×480 in 16:9. The fallback rung of the adaptive ladder for slow or metered…
Read →EncodingResolution
The pixel dimensions of a video frame — 480p, 720p, 1080p, 2160p (4K). Determines how sharp the picture looks on a given screen.
Read →