Resize Video Online by Pixels and Aspect Ratio
Choose a video size by pixels, percentage, device, HD–4K screen resolution, aspect ratio or social preset. Keep the whole picture, crop to fill or stretch it, then preview the actual output dimensions before downloading.
Choose a video to resize
Video processed on your device
Video is processed in your browser · The original file stays unchanged
Or drop a video here
One MP4, WebM, MOV, AVI or MKV file; playback depends on its codecVideo created. Play it before downloading.
How to resize and reframe a video
Choose a video
Drop or choose one video from your device. The tool reads its source dimensions and duration before showing the settings.
Set the output frame
Choose a device or platform preset, or size by pixels, percentage, an HD–4K screen or aspect ratio. Lock the ratio when one pixel dimension should update automatically.
Adjust composition
Choose Fit, Fill or Stretch. With Fill, drag the preview or use pan and zoom; with Fit, choose black, white, color or blur, and check a safe-zone guide if needed.
Export and review
Choose a quality level, enable or disable Do not upscale, then export one or several ratios. Play each result before downloading it individually or as a ZIP.
Choose Fit, Fill or Stretch for the result you need
| Goal | Recommended setting | Check and trade-off |
|---|---|---|
| Keep the whole source picture | Choose Fit; use a blur, color, black or white background for empty space. | The subject is not cropped, but it may look small when source and target ratios differ greatly. |
| Make the video fill the frame | Choose Fill, then drag the preview or adjust pan and zoom to retain the right subject. | Edges are cropped. Check the start and end because a moving subject may leave the selected area. |
| Need exact dimensions even if the picture distorts | Choose Stretch and enter the exact width × height. | Circles, faces and text can look squashed or elongated. |
| Only need a smaller file in KB/MB | Reduce pixels, choose Light quality and inspect the file; use the video compressor for a specific byte limit. | Dimensions and quality affect file size but do not guarantee a specific MB target. Video Compressor. |
| One video for several platforms | Enable Export multiple ratios, select the needed presets and process them sequentially. | Each version is a separate encode; several 1080p exports require more time and memory. They can be downloaded together as a ZIP. |
Pixels, crop, quality and safe zones
Four sizing methods share one output pipeline
Pixels allow up to 3,840 px per side; Percentage uses 1–400% of the source; Screen offers HD, Full HD, 2K and 4K; Aspect ratio derives a 1:1, 16:9, 9:16, 4:3, 3:4, 3:2, 2:3 or 4:5 frame from the source resolution.
Do not upscale is enabled by default
If the requested frame exceeds the source, the tool lowers both output dimensions and shows the actual size. Turn this option off if you still need the exact requested pixels.
Quality is a trade-off, not a file-size promise
High favors detail, Balanced is the default, and Light favors a smaller file. Source codec, duration and motion still strongly affect final size.
Safe zones are preview guides only
TikTok/Reels, Shorts or generic guides help place text and subjects in the preview; they are not burned into the export and do not replace platform specifications that may change.
Output depends on the device encoder
The tool prefers MP4 and may fall back to WebM when the device cannot encode MP4. MP4, WebM, MOV, AVI or MKV input still needs a codec supported by the browser or compatibility mode.
If the frame or export is not right
- Output dimensions are smaller than requested
- Do not upscale is protecting a smaller source. Check the “actual output” dimensions in the summary, or turn it off if exact pixels are required.
- Fill crops a person or text
- Return Zoom to 100%, drag the preview or adjust horizontal/vertical position. Fit is safer for a moving subject because one crop position applies to the whole video.
- Video is distorted or has empty space
- Stretch can distort; use Fill to cover the frame while preserving ratio. Empty space is normal in Fit and can use a blur or color background.
- The file will not open or process
- A file extension does not guarantee codec support. Try an MP4/WebM that plays on the device, reduce dimensions or export count; long videos and multiple 1080p versions need more memory.
Video processing on your device
The browser reads, composes and encodes the video; this resize workflow does not need to upload file contents to KitoTool servers. The original is unchanged. Multi-export creates versions sequentially, and the ZIP only packages results already created in the browser.
Video Compressor
Compress a video by adjusting quality or resolution, then preview and download the result.
Video Format Converter
Convert one MP4, WebM, AVI, MOV or MKV video to MP4, WebM or AVI in your browser, with output details to check before download.
Video Trimmer
Trim one continuous segment from an MP4 or WebM video by start and end time. Preview and download in the source format.
Video to MP3
Extract audio from a video and save it as MP3 with 128, 192 or 320 kbps options.
Automatic Video Subtitle Generator
Create subtitles from spoken video in your browser, review and edit each timed cue, then export SRT, VTT, TXT or a captioned video. Codec support depends on the browser.
Online Screen Recorder
Record a screen, app window or browser tab online. Capture supported system audio or microphone, preview and download the WebM video locally.
KitoTool Share — Screen Sharing
Share a screen, chat and meet new friends in public rooms, or create a private room with a code and password. Up to 4 people, no account required.
Video to GIF
Convert one MP4, WebM, MOV or M4V clip into a looping GIF; choose the clip, width, FPS, colors and dithering, then preview the real result.
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