tooloora

Change Video Resolution — scale to 1080p, 720p or 480p

Scale a clip down to a common resolution, keep the aspect ratio and see the size before and after — locally, no upload.

Runs locally — nothing is uploaded

Drop a video file here or click

MP4, MOV, WebM or MKV · one file · stays local

Runs locally in your browser – no upload.

Up to 30 minutes per video – longer material exceeds the browser's memory and your patience.

How do I change a video's resolution?

Drop the file, choose a target height (1080p, 720p or 480p), export. The width follows from the aspect ratio automatically, so nothing is stretched and no black bars appear. Scaling uses your device's own decoder and encoder, right in the browser — the file is never uploaded.

How much does a lower resolution save?

As much as the pixel count drops, provided the bitrate follows. Full HD is defined by ITU-R BT.709 as 1920 × 1080 picture elements, which is 2,073,600 pixels. 720p is 1280 × 720 = 921,600 pixels, about 45 percent of that. Going from 4K (3840 × 2160) to Full HD cuts the pixel count to a quarter. That is exactly why scaling down is the most effective lever when a file has to fit under a limit.

Why are the edge lengths always even numbers?

Because video codecs store colour information at half resolution in the common 4:2:0 format — one colour value per two-by-two block of pixels. Odd edge lengths do not divide evenly there, and many hardware encoders simply reject them. The tool therefore rounds down to the next even number; nobody sees a difference of one pixel.

Can I enlarge a video?

Deliberately not. Upscaling cannot invent detail: 720p does not become real 1080p, it becomes a soft 720p that needs twice the space. If you need a bigger picture, record again. What you get here is the honest direction — smaller, sharper per pixel, far more economical.

Honest limits

Scaling always means re-encoding, so a lossy source goes through a second compression. Processing takes roughly as long as the video runs, the tab has to stay open, and the cap is 30 minutes per file. Rotation metadata from phone recordings is carried over, so a portrait clip stays portrait.

Frequently asked questions

Is my video uploaded to resize it?

No. Scaling happens with your device's own decoder and encoder inside the browser; the file stays where it is. There is no server involved and therefore no upload wait.

How much smaller does a lower resolution make the file?

Roughly by the ratio of pixel counts, as long as the bitrate follows. 1080p (1920 x 1080) has 2 073 600 pixels, 720p (1280 x 720) has 921 600 — about 45 percent. Going from 4K to 1080p cuts the pixel count to a quarter.

Can I enlarge a video?

The tool deliberately only scales down. Upscaling cannot invent detail: 720p blown up to 1080p is a soft 720p that costs twice the storage. If you need a larger frame, re-record or keep the original.

Why are the output dimensions sometimes off by one pixel?

Video encoders want even edge lengths, because colour information is stored at half resolution in the common 4:2:0 format. An odd height like 1081 is therefore rounded down to 1080 — a difference nobody sees.

Does the aspect ratio stay the same?

Yes. You set the height, the width follows from the original ratio, so nothing is stretched or letterboxed. Rotation metadata from phone recordings is respected, so a portrait clip stays portrait.