Resizing video: resolution, aspect ratio and quality
Resizing changes the number of pixels in every frame. Making a video smaller (for example 1920×1080 to 1280×720) reduces the file size and is perfect for websites, email and older devices. Making it larger cannot add detail — it only helps when a platform requires a minimum size.
If the new size has a different aspect ratio than the original, you decide what happens: Fit keeps the whole picture and fills the gaps with black, white, a colour or a blurred background; Fill covers the whole frame and crops the edges; Stretch distorts the picture to the new shape.
Video encoders need even numbers, so odd sizes are rounded to the nearest even pixel. The Quality slider sets the bitrate relative to the new size, so a 720p video gets a sensible bitrate for 720p — not the bitrate of the 4K original.
Common video sizes
| Name | Size (pixels) | Typical use |
|---|---|---|
| 4K UHD | 3840 × 2160 | TVs, YouTube 4K |
| Full HD (1080p) | 1920 × 1080 | YouTube, presentations |
| HD (720p) | 1280 × 720 | Websites, email, older phones |
| Vertical 9:16 | 1080 × 1920 | TikTok, Reels, Shorts, Stories |
| Square 1:1 | 1080 × 1080 | Instagram and Facebook feed |
| Portrait 4:5 | 1080 × 1350 | Instagram feed (most screen space) |
Tips
- Only need standard resolutions such as 1080p → 720p? The Resolution Converter keeps the aspect ratio for every file automatically.
- Want to cut away part of the picture instead? Use the Video Cropper.
- Preparing a video for Instagram, TikTok or YouTube? The Social Video Resizer has presets for every platform.
- To make the file smaller without changing its size, use the Video Compressor.