Resize Video

A landscape clip needs to become a vertical Reel, a square post, or simply a smaller file for email. This tool resizes video in your browser: choose a target shape and resolution, decide whether to fit the whole frame with blurred or coloured bars or fill the frame by cropping, preview the result, and record a new file with the original sound.

Common target sizes

Platforms update their recommended specs from time to time; these are widely used current sizes. Uploading at the recommended size avoids the platform cropping or rescaling your video in ways you didn’t intend.

Fit vs fill

In fill mode, use the crop position slider to keep the subject in view — for example, slide left if the speaker stands on the left of a landscape frame.

Worked example

A 45-second 1920 × 1080 landscape clip of a talk needs to become a vertical Reel. Choosing 9:16 at 1080 × 1920 with “Fit, blurred background” keeps the whole speaker and slide, with the video filling the width and blurred copies above and below. At “Balanced” quality the estimate is around 25 MB. For a tighter look, “Fill” crops the sides; moving the crop slider to about 35% keeps the speaker, who stands left of centre, in frame. The same clip at 1280 × 720 for email comes out at about 10 MB.

Making files smaller

• Lower the resolution: 1280 × 720 has less than half the pixels of 1920 × 1080.
• Choose “Smaller file” quality for talking heads and screen recordings; keep “Balanced” or higher for fast motion.
• Trim the clip to what you need — duration affects size directly.
• Most email services limit attachments to around 20–25 MB; for larger files, share a link instead.

How it works and its limits

The tool plays your video into a hidden canvas at the new size, draws each frame with the fit or crop you chose, and records the canvas together with the original audio using the browser’s MediaRecorder. Because it records in real time, a 3-minute video takes about 3 minutes. The video is re-encoded, so quality can drop slightly. Keep the tab visible while it runs — browsers throttle background tabs. Very long or 4K videos are better handled by desktop software, which can also resize without re-encoding audio.

Aspect ratio basics

Aspect ratio is the shape of the frame, written as width to height. 16:9 is the standard widescreen shape of TVs and YouTube; 9:16 is the same shape turned upright for phones; 1:1 is square; 4:5 is a slightly tall rectangle that takes up more of a phone feed than a square. Resolution is how many pixels fill that shape — 1920 × 1080 and 1280 × 720 are both 16:9, just at different sizes.

Safe zones for vertical video

On Reels, TikTok and Shorts, the app overlays buttons, captions and the account name on the right side and bottom of the screen. Keep important text and faces away from roughly the bottom fifth and the right edge of a 9:16 frame. When you convert landscape footage with “Fit, blurred background”, the video sits in the middle band, which is usually clear of these overlays — one reason this layout is popular for repurposed clips.

Choosing the right approach for your footage

Resolution and quality

Upscaling — making a video larger than its original resolution — doesn’t add detail; a 720p clip resized to 1080 × 1920 will look soft. Where possible, choose a target at or below the original resolution, or use the “half the original size” option for a quick, lighter file. For clips with lots of motion, such as sports or dance, pick “Higher quality” so the encoder has more bits for fast-changing frames.

Formats

Recent Chrome and Edge versions usually save MP4 (H.264/AAC); Firefox and others save WebM (VP8/VP9 with Opus). Most social platforms accept both, but some older editing apps and iPhones prefer MP4. The tool reads whatever formats your browser can play — HEVC (H.265) iPhone videos may not play in every browser, in which case export them as “Most Compatible” (H.264) on the phone first.

Privacy

Your video never leaves your device. Processing happens entirely in your browser, and the new file exists only until you download it or close the page.