1080p vs 1080i: What’s the difference?

1080i and 1080pConfused by all this 1080i vs 1080p HDTV technobabble? We can’t blame you. Consumers today have more acronyms and abbreviations to remember than ever before, so keeping track of all of them and understanding their meaning is a never-ending challenge. Not to worry though, we’ve put together this super simple guide to help make sense of it all.

The Difference 

We’ll start with the abbreviations – 1080p is short for 1080 progressive scan, whereas 1080i is short for 1080 interlaced scan. The difference between these two formats is how they’re displayed on your screen. In an interlaced scan, the image is displayed by illuminating odd and even pixel rows in an alternating fashion. Your TV does this so rapidly (each field flashes 30 times per second) that your eyes aren’t capable of noticing the switch, so at any given moment you see what appears to be a fully-assembled picture.

Interlaced scan example

Progressive scan, other the other hand, scans every row of pixels progressively, refreshing every row on the screen 60 times per second. Technologically speaking, this is harder to pull off, but it’s generally agreed that progressive scan produces superior images compared to those produced via interlaced scan. This is why you’ll often hear 1080p touted as “true” or “full” HD by people hoping to differentiate it from 1080i or 720p. The benefits of progressive scan become especially apparent during scenes with lots of motion – just take a look at the pictures below and note the stark differences in clarity and sharpness.

Interlaced scan skateboarding
Interlaced scan
Progressive scan skateboarding
Progressive scan

While 1080p video is definitely preferable to 1080i, it’s also worth noting that unless you’ve got above-average eyesight, you probably won’t be able to notice a difference between the two on smaller screens. Generally speaking, you need a TV bigger than 42 inches in order to discern 1080i from 1080p – and that’s also dependent on how far away you’re sitting. Generally, for fast-moving images, 1080p offers superior image quality that prevents the appearance of the screen “tearing” that can occur with 1080i. 

Another thing to consider is that nearly all new HDTVs you can buy today are capable of de-interlacing 1080i video signals so they look just like 1080p, which makes it even harder to notice a difference.    

The ugly truth about your cable/satellite service’s HD signal

If you’ve noticed that the HD content you watch on your cable or satellite box pales in comparison to the picture quality you get from your Blu-ray player, or you get frustrated when your TV’s info bar shows that you’re watching 1080i even though you have a 1080p TV, you’re not alone in your disappointment. There is a reason for this, however. 

The only way cable and satellite companies can deliver 3,000 channels (ok, maybe we’re exaggerating a little), many of them in HD, is by compressing their video signals in an effort to squeeze more information into a crowded pipeline. This compression robs the signal of its pristine clarity and sharpness and can introduce blocky color gradations into the picture. For a highly revealing example of the difference, try tuning into one of your locally broadcast HD stations on both your cable/sat box and through your TV’s tuner (you will need an HD antenna for this). Now switch back and forth between the two and note the difference in quality. 


if you just read this article, we feel like it’s safe to assume you might be in the midst of a full-on HDTV research spree. If that’s the case, then we highly recommend checking out the following guides to boost your knowledge: