Resize Video Online
Processing entirely on your device — large files may take a moment.
Fill in the width, the height, or both — an empty side is scaled automatically to keep the picture undistorted, rounded to an even number because H.264 requires it. 1080p to 720p halves the file; 720p to 480p works for messaging apps.
Downscaling is the honest way to shrink a video: every frame keeps the full picture, just with fewer pixels, so nothing is cut away. Audio passes through untouched.
How to resize video
- 1
Select your files
Drag & drop your MP4 files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to MP4". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted MP4 file individually, or grab everything at once as a ZIP archive.
About the MP4 format
MP4 (MPEG-4 Part 14) is the universal delivery container of digital video. It wraps H.264, HEVC or AV1 video with AAC audio, and its structure — separate metadata (moov) and media atoms — is what makes streaming, seeking and fast-start playback possible. Phones, cameras, TVs, browsers and every social platform assume MP4 first.
Quality is entirely a function of the codec and bitrate chosen at encode time, so an MP4 can be a 10 Mbps HEVC master or a postage stamp. That flexibility plus total playback coverage is why nothing has displaced it in twenty years — conversion between formats almost always ends in MP4.
+Strengths
- ✓Plays on every device and platform in existence
- ✓Streaming-ready structure (fast start, seeking)
- ✓Choice of modern codecs: H.264, HEVC, AV1
!Limitations
- −Quality depends entirely on encode settings
- −HEVC variants hit licensing gaps on some platforms
Frequently asked questions
Can I upscale a small video?
Technically yes, but upscaling cannot invent detail — large upscales look soft. Downscaling is where this tool shines.
Why must dimensions be even numbers?
H.264 and most players expect even dimensions; the tool rounds the auto-calculated side to the nearest even number for you.
How much smaller will the file be?
Roughly proportional to the pixel count: 1080p→720p is about 55%, 1080p→480p about 20% of the original, depending on content.