Video Resizer
Resize Video Resolution and Dimensions Online
Video Resizer
Use this video resizer to change video resolution and dimensions. For example, reduce a 1080p video to 720p, convert 4K footage to 1080p, or set custom output width and height. The tool supports keeping the original aspect ratio or freely adjusting dimensions, then exports the processed video as an MP4 file.
Which video resolutions are supported?
Four common presets are available: 1920×1080 (1080p), 1280×720 (720p), 854×480 (480p), and 640×360 (360p). You can also enter custom width and height values from 16 to 7680 pixels to meet different video resizing requirements.
How do I keep the video aspect ratio?
When aspect ratio lock is enabled, the tool automatically calculates the video height based on the target width. This helps preserve the original proportions and prevents people or objects from appearing stretched horizontally or vertically. When disabled, you can set the width and height independently, but the image may become distorted.
How do I resize a video?
- Select or drag and drop the video file you want to process.
- Choose the 1080p, 720p, 480p, or 360p preset, or enter custom width and height values.
- Enable or disable aspect ratio lock as needed.
- Click Start Resizing and wait for the browser to finish re-encoding the video.
- Preview the result and download the generated MP4 file.
Can lowering video resolution reduce file size?
Usually, yes. Reducing a 4K or 1080p video to a lower resolution such as 720p or 480p decreases the number of pixels. Re-encoding will often produce a smaller file. However, the final file size also depends on video content, encoding settings, and audio data, so a smaller file is not guaranteed every time.
Does resizing affect video quality?
Video resizing uses H.264 re-encoding with the yuv420p pixel format and CRF 23 encoding setting. Reducing resolution removes some image detail, while increasing resolution cannot restore details that are absent from the original video. Re-encoding may also cause some quality loss.
Which video formats are supported?
The tool reads video files through a browser-based video processing module. Actual input format support depends on the browser and FFmpeg decoding capabilities. Common formats such as MP4, WebM, MOV, and MKV may be processed depending on their codecs. All processed videos are exported as MP4 files encoded with H.264.
Will the audio be preserved after resizing?
If the original video contains an audio track, the output uses AAC encoding at 128 kbps. If the original video has no audio track, no audio will be added. Audio is re-encoded rather than copied losslessly from the original file.
Are videos uploaded to a server?
No. Video resizing runs locally in your browser. Files are read, encoded, and exported through the local video processing module without being uploaded to a server. Keep the page open during processing. Large video files may use significant device memory and CPU resources.
What can video resizing be used for?
- Reduce 4K videos to 1080p to lower resolution and storage requirements.
- Convert 1080p videos to 720p or 480p for different publishing platforms.
- Set custom video dimensions for specific playback devices or page layouts.
- Adjust the resolution of phone recordings and educational videos.
- Reduce video dimensions to make sharing, transferring, and storing files easier.
Frequently Asked Questions
Do I need to install software to resize videos?
No desktop software is required. Open the tool in a browser that supports the necessary video processing capabilities.
Can I upscale a 720p video to 1080p?
Yes. You can enter larger output dimensions, but upscaling does not add original image details. The actual quality remains limited by the source video.
Why does processing a large video take longer?
Video re-encoding uses CPU and memory resources. Processing speed depends on video duration, resolution, encoding complexity, and device performance. Larger videos may take considerably longer.
Why is the output file larger than the original?
The size of a re-encoded file depends on image complexity, original encoding quality, and audio data. Even when the resolution is reduced, the output file is not guaranteed to be smaller.
How to Resize Video Dimensions and Resolution Online
Select a video file and use the 1080p, 720p, 480p, or 360p presets to change its resolution, or enter custom output width and height values. Enable aspect ratio lock to calculate the video height automatically and prevent image distortion.
- Provides common 1080p, 720p, 480p, and 360p resolution presets
- Supports custom video width and height
- Preserves the original aspect ratio and automatically calculates output height
- Allows aspect ratio lock to be disabled for independent width and height settings
- Can reduce high-resolution videos to common output sizes
- Re-encodes videos with H.264 and exports them as MP4
- Uses AAC 128 kbps encoding when the original video contains an audio track
- Processes videos locally in the browser without uploading files to a server
- Supports video preview and downloading the processed result