Free tool · runs in your browser

Social Video Resizer

Reframe one video to every platform’s shape: vertical 9:16, portrait 4:5, square 1:1, or landscape 16:9, by cropping or padding, entirely in your browser. Your video never leaves your device.

One video, several shapes

A single piece of footage rarely fits everywhere. Short-form lives full-screen at 9:16; the Instagram and Facebook feed reward the taller 4:5; YouTube and LinkedIn are still widescreen 16:9. Rather than re-export from your editor four times, reframe the finished video here for each destination. It’s the video half of the repurposing workflow , one core asset and many native cuts, and for still images the image resizer does the same job.

Crop to fill, or fit and pad

Two ways to change a frame’s shape, and the right one depends on what can be lost. Crop to fill reframes the video to the new ratio and trims the overflow. No bars, but the edges get cut, which is why you pick the anchor for what stays in frame. Fit & pad shrinks the whole frame to fit and fills the gap with a colour, so nothing is cut but you get bars on two sides. Crop for footage where the action sits central; pad when text or edges of the frame have to survive.

How it works

How to resize a video

Upload, pick a shape, and download. The whole flow:

  1. 1

    Upload your video

    Drag in or pick an MP4, MOV, or WebM up to 500 MB. It's read into the browser, and nothing uploads.

  2. 2

    Pick the target shape

    Vertical 9:16, portrait 4:5, square 1:1, or landscape 16:9, each labelled with the platforms it's for.

  3. 3

    Choose crop or pad

    Crop to fill reframes the video to the new shape (pick what stays in frame); fit & pad keeps the whole frame and adds bars in a colour you choose.

  4. 4

    Resize in your browser

    The first run downloads the video engine once, then re-encodes locally. Bigger clips take longer.

  5. 5

    Download and post

    Save the MP4: a normal H.264 file with audio, ready to upload to the platform you sized it for.

Which video shape for which platform

Four shapes cover every major surface. Pick the one that matches where the video is going:

ShapeRatioBest forWhy
Vertical9:16TikTokReelsShortsFull-screen vertical, the default for short-form.
Portrait4:5InstagramFacebookThe tallest shape the feed shows, and the most screen height.
Square1:1InstagramFacebookXSafe everywhere; reads the same on any device.
Landscape16:9YouTubeLinkedInWidescreen, native for long-form and desktop.

Resize video for TikTok, Reels, and Shorts

Short-form is vertical; the feed and YouTube are not. Which aspect ratio to pick per destination:

Video resizer for TikTok

TikTok is full-screen vertical: 9:16(1080×1920). Crop to fill so the subject takes the whole frame, dragging the focal point to keep it centred, or pad if you’d rather not lose the edges.

Resize video for Instagram Reels

Reels and Stories are 9:16 too. For a video going to the Instagram feed rather than Reels, 4:5 (1080×1350) is the taller, higher-footprint option that still plays inline.

YouTube Shorts video resizer

Shorts use the same 9:16 vertical frame; standard landscape YouTube uploads are 16:9 (1920×1080). The resizer does both, so one source clip can become a Short and a regular upload.

Square (1:1) video for the feed

A 1:1 (1080×1080) square crop is the safe, platform-agnostic option for a feed post that has to look right on Instagram, Facebook, and X at once, with no orientation surprises.

Frequently asked questions

Is my video uploaded to a server?

No. The re-encoding runs entirely in your browser using a video engine (ffmpeg compiled to WebAssembly) that downloads once and then works on your device. Your video is never sent anywhere, so you can resize confidential or unreleased footage safely.

Why is there a one-time download, and why can it be slow?

Because the work happens on your machine, not a server, the video engine (about 25 MB) downloads to your browser the first time and is then cached. And re-encoding video is genuinely heavy: a long or high-resolution clip can take a while on a laptop. It's the trade for keeping the file private and the tool free. For a quick crop, a short clip finishes in seconds.

What's the difference between crop to fill and fit & pad?

Crop to fill reframes the video to the new shape and trims the overflow. No bars, but the edges get cut, so you pick which part stays in frame. Fit & pad shrinks the whole frame to fit inside the new shape and fills the leftover space with a colour, so nothing is cut but you get bars on two sides. Use crop for footage where the action is central, and pad when every part of the frame matters.

What size should a TikTok or Reels video be?

Vertical 9:16, which renders at 1080×1920, which is the size for TikTok, Instagram Reels, and YouTube Shorts, all of which are full-screen vertical. For a video going to the Instagram feed instead of Reels, 4:5 (1080×1350) is the taller option; for a square feed post, 1:1 (1080×1080); for landscape YouTube, 16:9 (1920×1080). This resizer crops or pads any source video to whichever of those you need, in the browser.

What formats and sizes work?

Upload MP4, MOV, or WebM up to 500 MB; the output is always an MP4 (H.264 video, AAC audio) that plays everywhere and uploads cleanly to every platform. Very large files use more memory, so if a clip stalls, trim or compress it first.

Does resizing lose quality?

It re-encodes once at a high-quality setting, so the result is visually close to the source. The loss is the normal cost of any re-encode, not a heavy compression. If your goal is a smaller file rather than a new shape, run it through a compressor instead; resizing is about the frame, not the file size.

Does it change the length or speed of the video?

No. It only changes the frame: the shape and what's visible. The duration, frame rate, and audio are untouched. Crop and pad both keep the full timeline; they just reframe each frame to the aspect ratio you chose.