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Plan video framing and dimensions clearly
Calculate reduced ratios and scaled dimensions before editing. To change the canvas, keep the full subject and fill margins with a solid color or blurred source video. Useful for landscape-to-portrait adaptation, square assets and placement planning.
Video ratio features
- Dimension calculation: GCD ratio reduction, width/height scaling and even alignment.
- Canvas adaptation: 16:9, 9:16, 4:3, 1:1, 4:5 and custom ratios, centered without stretching.
- Local export: solid/blur backgrounds, audio options, progress and cancellation, with browser-supported formats.
How to use the video ratio tool
For calculations, enter source dimensions, target side and rounding, then inspect reduced ratio and actual output.
To convert video, choose a file, ratio, short-side size and fill mode; check the preview first.
Choose audio and format, keep the page visible during processing, then preview and download.
Video ratio use cases
Plan editing resolutions, adapt landscape clips to portrait canvases, confirm social dimensions and prepare delivery size lists. Aspect adaptation does not replace platform checks for duration, bitrate or file size.
Video aspect ratio FAQ
How do calculation and conversion differ?
Calculation works only with numbers, without a file. Canvas conversion reads local video, draws frames and backgrounds, and re-encodes a new video. Calculation alone does not modify or export video.
Why can rounding slightly change the ratio?
Theoretical dimensions can contain fractional pixels; encoders commonly use integer or even sizes. The calculator shows theoretical size, actual result and deviation. Even alignment may change the known side. Conversion uses even multiples of the reduced ratio.
Why is conversion real-time? Can I switch tabs?
This uses local browser playback, canvas and recording, so processing usually approaches source duration and depends on device performance. Keep the page visible; backgrounding stops and discards partial output to avoid missing frames. Cancel at any time.
Are MP4, audio and lossless conversion supported?
Only formats encodable by the current browser are shown: WebM, MP4 or one of them. Audio retention needs element capture; otherwise silent export is available. Missing capturable audio is explicitly marked. Re-encoding is not lossless.
Is the source stretched, cropped or uploaded?
The subject is centered with contain, without stretching or cropping. A blurred background covers the canvas and is cropped at its edges. Files and settings are not uploaded or persisted. Download before leaving. Input: up to 5 min / 200 MB; output: up to 100 MB.