Change Video Resolution

Two decisions, not one

This is what the tool gets right and most others hide, and understanding it takes thirty seconds.

The first decision is size: how many pixels wide and tall you want. That is usually forced on you — an upload limit, a platform requirement, a file that needs to be smaller.

The second is shape: what to do when your video's proportions do not match the target's. A phone video shot upright is tall; 1080p is wide. Something has to give, and there are only three possibilities.

Letterbox — the default — fits the whole picture inside the target and fills the leftover space with black bars. Nothing is lost and nothing is distorted. This is the safe choice and the right one when the content matters more than the framing.

Crop to fill scales the video until it covers the whole target and cuts off whatever hangs over the edges, centred. Nothing is distorted and the frame is completely filled, but you lose the edges — which for an upright video squeezed into a wide frame means losing a great deal.

Stretch forces the picture to the exact dimensions regardless of shape. Everything fits, nothing is cut, and everybody looks wrong — faces widen, circles become ovals. There is almost no good reason to choose this, with one exception: a video whose shape was already recorded incorrectly, where a stretch puts it back.

Most tools make this choice for you silently, which is why people end up with unexpectedly cropped or oddly squashed video and no idea which setting caused it.

Upscaling cannot add detail

The tool warns you about this on screen when your target is bigger than your source, and it is worth understanding why the warning is there.

Detail that was never captured cannot be recovered. Taking a 480p video to 4K spreads the same information across nine times as many pixels — the file gets much larger, the encode takes much longer, and the picture looks exactly as soft as before, only bigger. A blurry video at 4K is a blurry video.

The two situations where it is still worth doing are worth knowing, because they are real: a platform that refuses anything under a minimum resolution, and a project where every clip must match a single timeline resolution. In both cases you are satisfying a requirement, not improving the video, and it is fine to do it knowingly.

Otherwise, leave it at its native resolution. Nothing is gained.

Going down, which is what most people want

Reducing resolution is the common case and it genuinely helps.

Halving the dimensions quarters the pixel count, and file size falls steeply — usually much more than people expect. 1080p to 720p typically cuts the file to somewhere around half while looking essentially identical on a phone, which is where most video is watched. It is the single most effective change when something is too big to send or upload.

Rough guidance on the presets: 1080p for anything going on a television or a large monitor. 720p — the default here — for social platforms, messaging, email attachments and anything watched on a phone. 480p when size matters more than looks, such as a long screen recording or a reference copy. 360p and 240p for a proof or a preview.

If your goal is purely a smaller file rather than a specific resolution, reducing resolution is not the only lever — Video Compressor lowers the bitrate while keeping the dimensions, which for many videos gives a better-looking result at the same file size. Try that first if the pixel dimensions do not matter to you.

The black bars are permanent

An honest detail that catches people out later.

Letterbox bars are not metadata — they are real black pixels drawn into every frame. Once the file is written they are part of the picture and cannot be removed without cropping them off, which loses a little of the real image at the same time.

That matters when the video goes somewhere with a different shape again. A tall video letterboxed into a wide frame, then uploaded to a platform that shows it in a tall frame, gets a second set of bars added on top — bars on all four sides, with your video as a small rectangle in the middle.

So letterbox for a known destination, and match the shape to it. If the video is going somewhere upright, choose a custom size that is upright. And if you need to change shape rather than size, Crop Video is the tool that does it deliberately.

What the conversion costs

Changing resolution re-encodes the video — there is no way around it, because every frame is being redrawn at a new size. Three things follow.

There is a small quality cost beyond the resolution change itself, from the fresh compression. It is modest, and invisible in one pass. It does accumulate, so do not convert the same file repeatedly — go back to your original each time.

It takes real time. Every frame is processed, so a long or high-resolution video is a wait, and the work happens on your own machine rather than a server. The video engine also loads into your browser on first use — a sizeable download, cached afterwards.

The audio is left completely alone. The soundtrack is copied across rather than re-encoded, so there is no audio quality loss at all and nothing to configure. That is the right behaviour and not every tool does it.

The output is an MP4. Your source resolution is shown as soon as you upload, so you can see what you are starting from before choosing a target. Custom sizes keep the aspect ratio by default, with the height following the width — and in that mode the letterbox-or-crop choice does not apply, because there is no mismatch to resolve.

Related tools

Resize Video covers the same ground from a different angle — it works in percentages and presets where this works in named resolutions, and it ties the shape handling to the mode you pick rather than letting you choose separately. Use this one when you need a specific standard resolution and want to control the fit. Video Compressor shrinks the file without changing the dimensions, which is often the better answer. Crop Video changes the shape of the frame deliberately rather than padding or cutting to fit.