Video Resizer — Change Resolution and Aspect Ratio
Change a video’s resolution, or fit it to a square, vertical or widescreen frame for Instagram, TikTok, YouTube and more. Processed on your device, with no upload.
Drop a video file here or
Your video never leaves your device. Everything is processed in this browser tab: no upload, no server copy.
How to resize a video
- Drop a video onto the box or click "Choose video".
- Choose a resolution to keep the same shape, or a social media frame. For frames, choose whether to crop the edges, add black bars, or stretch.
- Click "Resize video", check the preview, then click "Download video".
Resolution or frame: two kinds of resizing
Keeping the shape scales the whole picture to a standard height such as 1080p or 720p, so nothing is cropped. Portrait phone videos are scaled by their width instead, so "720p" gives a 720-pixel-wide vertical video. Use this to make a 4K video easier to edit or share, or to match a project’s resolution.
Social media frames change the shape. "Fill the frame" scales the video until the frame is covered and crops what sticks out, which is the usual choice for turning a landscape clip into a vertical Reel or TikTok. "Fit inside" shows the whole picture with black bars, and "Stretch" fills the frame by distorting the image.
Quality
The resized video is encoded as an H.264 MP4 at high quality. Making a video smaller keeps it sharp; making it larger than the original cannot add detail, so it only helps when a platform requires a minimum size. The sound is kept unchanged.
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Frequently asked questions
Is my video uploaded?
No. The video is processed by your own browser using its built-in video encoder. Nothing is sent to a server, so private videos stay private.
What size should I use for Instagram Reels and TikTok?
Vertical 9:16 at 1080 × 1920. For feed posts, Portrait 4:5 (1080 × 1350) fills the most screen space.
Will resizing crop my video?
Only with "Fill the frame". Standard resolutions keep the whole picture, and "Fit inside" adds black bars instead of cropping.
Can I make a video larger?
Yes, but upscaling cannot add detail that was not recorded, so the video will not look sharper.
Which browsers does it work in?
Recent Chrome, Edge and Opera on desktop and Android, Safari 26 on Mac and iPhone, and Firefox 130 or newer on desktop. These browsers include the WebCodecs video encoder the tool uses.