Guide5 min read
How to Resize a Video (Any Size, No Upload)
Resize a video to 1080p, 720p, 480p, or Instagram and TikTok sizes in your browser. Learn when to use Fit, Fill, or Stretch, with no upload.
Resize video
Change a clip to 1080p, 720p, square or vertical — free and processed in your browser.
Drop a video here, or click to browse
MP4, MOV, WebM, MKV, or AVI — up to 2GB
A video resizer with the sizes you actually need
The sizes people actually ask for
1080p, 720p, 480p, and 360p for landscape, plus 9:16, 1:1, and 4:5 for social feeds. Pick from a list instead of doing aspect-ratio math.
You choose what happens when shapes differ
Fit keeps the whole picture with bars, Fill crops to cover the frame, and Stretch forces the size. A plain-language line under the control says what each one will do.
Ready for vertical feeds
Turn a landscape clip into a 1080×1920 vertical video for Reels, TikTok, and Shorts, or into a square for feed posts, in a single pass.
Audio passed through untouched
The soundtrack is copied across rather than re-encoded, so resizing costs you nothing in audio quality.
Takes the format your camera gave you
MP4, MOV, WebM, MKV, and AVI all go in as they are, and everything comes back as MP4, the format every editor and platform accepts.
Runs on your machine, not ours
ffmpeg.wasm does the work inside the browser tab. No upload, no server-side copy of your footage, no account to create first.
Resize a video in three steps
- 1
Add the video you want resized
Drop an MP4, MOV, WebM, MKV, or AVI file onto the page, up to 2GB. It is read straight off your disk, not sent anywhere.
- 2
Pick an output size and how to fit it
Choose 1080p, 720p, 480p, 360p, or a social shape: 9:16 vertical, 1:1 square, or 4:5 portrait. If the new shape differs from the clip, Fit adds black bars, Fill crops the edges, and Stretch forces the picture to the new size.
- 3
Resize and save the MP4
One click runs the resize in your browser and hands back an MP4 you can download immediately. No queue, no watermark, no account.
When a video needs a different size
A file too big to email, a landscape clip headed for a vertical feed, a 4K recording that stutters on an old laptop — each one is a size change away from working.
Posting a landscape clip to Reels, TikTok or Shorts
Turn a 16:9 recording into a 9:16 vertical video. Fill gives the full-screen look, Fit keeps the whole shot with bars above and below.
Getting a video under an email or upload limit
Dropping from 4K or 1080p to 720p or 480p shrinks the file dramatically, often enough to fit a mail attachment or a forum's upload cap.
Making a heavy recording play smoothly
A 4K screen recording can stutter on an older laptop or a slow connection. A 1080p or 720p copy plays cleanly where the original will not.
Matching clips to one project size
Footage from different cameras and phones arrives in different sizes. Resizing them all to one target keeps an editor's timeline from rescaling each clip its own way.
Frequently asked questions
What is the difference between Fit, Fill, and Stretch?
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They only matter when the new size has a different shape from your clip, for example a 16:9 landscape video going to 9:16 vertical. Fit keeps the whole picture and adds black bars top and bottom or left and right. Fill zooms in until the frame is covered and crops whatever spills over. Stretch squashes the picture to the new shape, which distorts people and text, so it is rarely what you want unless the shapes already match.
How do I resize a video for Instagram, Reels, TikTok or Shorts?
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Pick 9:16 vertical (1080×1920) for Reels, TikTok, and YouTube Shorts, 1:1 square (1080×1080) for square feed posts, or 4:5 portrait (1080×1350) for feed posts that use the most screen space. For a landscape clip, Fill gives the full-screen look at the cost of cropping the sides, and Fit keeps everything visible with bars.
Will making a video smaller reduce the file size?
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Usually a lot. Fewer pixels per frame means less data to store, so dropping a 4K clip to 1080p or a 1080p clip to 720p typically cuts the file to a fraction of its size. The exact saving depends on the footage. If size is your main goal and the dimensions do not matter, the Compress Video tool is built for that.
Does resizing lose quality?
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Scaling down always discards detail, because the picture has fewer pixels, but the result is encoded with H.264 at CRF 23, a setting that looks clean for almost all footage. Scaling up does not add detail, it only stretches what is there, so making a 480p clip 1080p will not make it sharper.
What happens to the sound?
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The audio is copied across untouched rather than re-encoded, so it stays exactly as it was. The one exception is a source whose audio codec an MP4 cannot hold, Opus or Vorbis inside a WebM for example, where the audio is converted to 192 kbps AAC so the result plays everywhere.
Can I type in a custom width and height?
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Not yet. The tool offers the seven sizes people ask for most: 1080p, 720p, 480p, 360p, 9:16, 1:1, and 4:5. If you need a size that is not on the list, tell us which one and it can be added.
Do my videos get uploaded to PixelTools?
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They do not. The resize runs through ffmpeg.wasm inside your own browser tab, so the file never crosses the network. There is no upload wait, no server-side copy of your footage, and no file-size limit imposed by a server.
Can I resize a video on my phone?
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Yes, the page works in mobile Safari and Chrome without installing anything. A phone has less memory and a slower processor than a laptop, so a long 4K clip is better handled on a desktop, while short clips resize comfortably on the phone.
Resize your video now
Free, no account needed.