Change Video Resolution
Resize videos to 360p, 480p, 720p, 1080p, 1440p, or 4K instantly. Free, private, and entirely browser-based — your files never leave your device.
Drop files here or browse
Supports MP4, WebM, MOV, AVI — up to 500 MB
Resolution change tips
Downscale for sharing
Reduce 4K or 1080p videos to 720p or 480p for faster uploads to social media and messaging apps.
Upscale with caution
Upscaling adds pixels but cannot add detail. A 720p video upscaled to 4K won’t look sharper — it will just be a larger file.
Aspect ratio preserved
Height is auto-calculated to match your original video’s proportions. No stretching or black bars.
All formats
Works with MP4, WebM, MOV, and AVI video files. Output format matches your input automatically.
Privacy first
Everything is processed entirely in your browser using WebAssembly. Your videos are never uploaded to any server.
How to change video resolution online
Resizing video resolution is essential for optimizing files for different platforms. A 4K video recorded on your phone may need to be downscaled to 720p for email attachments, or an older 480p clip might need to be brought up to 1080p for a presentation. This free tool handles both directions with high-quality encoding.
The tool uses FFmpeg WebAssembly to re-encode your video with a new resolution directly in the browser. The scale filter automatically calculates the height to maintain your original aspect ratio, and the -2 parameter ensures even pixel counts for H.264 and VP8 codec compatibility. Audio is stream-copied without re-encoding since only the video dimensions change.
All processing runs entirely in your browser using WebAssembly. Your video files are never uploaded to any server, ensuring complete privacy. The first use requires a one-time download of the FFmpeg engine (~30 MB), after which subsequent operations start immediately.
Frequently asked questions
How do I change video resolution?
Drop or select your video file, choose a resolution preset (360p through 4K), and click ‘Change Resolution’. The resized video downloads automatically when processing is complete.
Does upscaling improve video quality?
No. Upscaling adds pixels but cannot add detail that wasn’t captured originally. A 720p video upscaled to 4K will be a larger file but won’t look sharper.
What resolution presets are available?
360p (640×360), 480p (854×480), 720p HD (1280×720), 1080p Full HD (1920×1080), 1440p QHD (2560×1440), and 4K UHD (3840×2160).
What’s the file size limit?
The maximum file size is 500 MB. Larger files may cause browser performance issues since all processing happens locally.
Will the aspect ratio change?
No. The height is auto-calculated to maintain your video’s original aspect ratio. There’s no stretching, cropping, or black bars.