動画リサイズ
Change video dimensions with preset resolutions or custom sizes.
Drag & drop a video file here
or click to browse · MP4, WebM, MOV, AVI, MKV (max 2 GB)
How It Works
- Upload your video: Select or drag a video file you want to resize.
- Set target dimensions: Enter the width and height in pixels, or choose a preset (1080p, 720p, 480p, 360p, 240p). Enable "Maintain aspect ratio" to prevent distortion.
- Download the resized video: Click Resize and download the output video at your chosen dimensions.
Why Use Video Resizer?
Platform requirements, bandwidth constraints, and embedding targets all demand specific video dimensions. Instagram requires square or portrait video, YouTube wants 16:9, Twitter has upload size limits, and embedded players need specific pixel dimensions to fill their containers. Resizing video in your browser avoids installing video editors or paying for cloud processing services — and keeps your footage private.
Features
- Custom dimensions: Enter any width and height in pixels.
- Aspect ratio lock: Maintain the original aspect ratio automatically when setting one dimension.
- Common presets: Quick presets for 4K, 1080p, 720p, 480p, and social media formats.
- No distortion: Optional letterboxing to avoid stretching the video.
- Browser-based processing: Your video files stay on your device throughout the entire process.
Frequently Asked Questions
What is the maximum input video resolution?
The tool can handle videos up to the memory and compute limits of your browser. 4K (3840×2160) videos work on modern devices, though processing time increases significantly with resolution.
Will resizing reduce quality?
Downscaling (reducing resolution) involves some quality loss inherent in the compression. The tool uses high-quality resampling. Upscaling beyond the original resolution will not add detail — it just makes pixels bigger.
How do I resize video for Instagram?
For Instagram Feed posts: 1080×1080 (square) or 1080×1350 (portrait). For Stories and Reels: 1080×1920. Select the preset or enter these dimensions manually with aspect ratio lock enabled.