# Resize Video Online Shrink or enlarge your clip by percentage and see the new resolution and estimated file size before you export. Processed locally in your browser - no upload, no watermark. HTML: https://grepcut.com/en/tools/resize-video ## How to Resize a Video Online 1. **Add your video**: Drop your file into the tool or click to browse. The video is processed locally on your device. 2. **Choose a percentage**: Pick 10%, 25%, 50%, 75%, 125%, 150%, 200% or 400%. You can compare the original resolution with the expected output instantly. 3. **Export your MP4**: Click Apply to download the resized MP4, or open the clip in GrepCut Studio if you want to keep editing. Need a custom canvas, crop or repositioning instead of simple scaling? Open your clip in [GrepCut Studio](/). ## Scale Your Video Without Stretching It This tool resizes by percentage, so width and height change together. Your video keeps its original aspect ratio, which helps avoid the stretched faces, oval circles and black-bar surprises that happen when a clip is forced into the wrong shape. Use Resize when you want the same frame, just smaller or larger. If you need a vertical clip for Reels, a square post, a 16:9 canvas or a manual crop, open the file in GrepCut Studio instead. ### Presets included: - **10% to 25%**: Make a very large clip much smaller for quick sharing, rough review or low-bandwidth uploads. - **50% to 75%**: Reduce a 4K or high-resolution export while keeping a watchable frame for web, email and social posts. - **125% to 200%**: Create a larger frame when your source is a little too small for the place you want to upload it. - **400%**: Use the maximum upscale for tiny source clips, with the quality still limited by the original file. Before export, you can see the original and expected resolution side by side, plus an estimated output size. ## Why Resizing Can Make Your File Easier to Share A smaller frame has fewer pixels per video frame, so the encoder has less visual information to store. That is why scaling down can make your file easier to upload to chat apps, email, course portals or social platforms. The estimate is based on pixel count, so it is useful for choosing a scale before you export. The final file can still vary because motion, audio, source compression and encoder settings all affect the finished MP4. ### A practical rule: - **Too big to send**: Try 50% or 75% first, then check whether the previewed resolution is still enough. - **Already blurry**: Avoid heavy upscaling. A bigger frame will not create real detail that was never captured. - **Needs a different shape**: Use crop or canvas tools instead of percentage resize. ## Which Resize Percentage Should You Pick? | Your goal | Good starting scale | What you should expect | | --- | --- | --- | | Quick preview or email attachment | 10% or 25% | A much smaller frame and file, best for review rather than final publishing. | | Reduce a 4K clip for upload | 50% or 75% | A smaller MP4 that usually keeps enough detail for everyday web sharing. | | Make a small clip fit a larger layout | 125% or 150% | A larger frame with no new captured detail, useful when the source is close to your target size. | | Maximize a tiny source clip | 200% or 400% | A bigger output that may look softer or more compressed, depending on the original. | For platform-specific crops like 9:16, 1:1 or 16:9, use [Crop Video](/tools/crop-video) or open the clip in [GrepCut Studio](/). ## Your Video Stays on Your Device Resize runs in your browser, so your file is not uploaded to a server. That matters when your clip contains private footage, client material, a class recording or a large file that would be slow to send anywhere first. Because the work happens locally, performance depends on your computer or phone. Large 4K files need more memory, and export speed depends on browser support and hardware-accelerated encoding where available. For the smoothest export, use a WebCodecs-capable browser such as Chrome, Edge or Opera. ## Browser Video Resizing at a Glance ### Advantages - Private processing with no upload. - Live resolution and estimated file-size preview. - Simple percentage presets from 10% to 400%. - Exports a standard MP4 with no watermark and no account. ### Disadvantages - Very large 4K files depend on your device memory. - Upscaling cannot recover detail missing from the source. - Percentage resize does not crop, pad or reframe to a new aspect ratio. - Export needs a WebCodecs-capable browser. ## Resize Video Online - FAQ ### Can you resize a video without uploading it? Yes. Your video is processed in your browser, so it stays on your device. You only download the new MP4 when you export. ### Will resizing make your video file smaller? Scaling down often makes the file smaller because the output has fewer pixels per frame. The exact size still depends on motion, audio and how the browser encodes the MP4. ### Will your video get stretched? No. Resize scales width and height by the same percentage, so the original aspect ratio is preserved. ### Can you resize a 4K video to 1080p? Yes, if the percentage you pick lands near that target. For example, 50% turns a 3840 × 2160 clip into 1920 × 1080. ### Can you change a landscape video into vertical video here? Not with percentage resize alone. Use [Crop Video](/tools/crop-video) or GrepCut Studio when you need a 9:16, 1:1 or custom canvas. ### Does 200% or 400% upscaling improve quality? It makes the frame larger, but it does not recreate detail that was missing in the source. If the original is blurry or heavily compressed, the bigger export may still look soft. ### Why is the exported file size different from the estimate? The estimate is based on the resolution change. Real output size can shift because video content, audio, source compression and browser encoding all affect the final MP4. ### What format do you get back? You get a standard MP4 using H.264 video, designed for broad playback and clean uploads across common platforms. ## Sources & further reading - [Reddit discussion about reducing very large video files](https://www.reddit.com/r/techsupport/comments/1cl75i7/best_way_to_compress_large_video_files_to_someone/) - [Super User thread about resizing video to make it smaller](https://superuser.com/questions/624563/how-to-resize-a-video-to-make-it-smaller-with-ffmpeg) - [Adobe Community answer about aspect ratio mismatch and distortion](https://community.adobe.com/questions-329/issues-with-resizing-video-1226255) - [VideoHelp forum discussion about whether upscaling is worth it](https://forum.videohelp.com/threads/414288-Is-it-worth-upscaling-video) - [MDN guide to the WebCodecs API](https://developer.mozilla.org/en-US/docs/Web/API/WebCodecs_API) - [MDN web video codec guide](https://developer.mozilla.org/en-US/docs/Web/Media/Guides/Formats/Video_codecs) ## Resize, then make your clip pop Open your resized clip in GrepCut Studio to add captions, music and effects. You can keep editing in the browser after the percentage resize is done. ## Related Tools - [Crop Video](https://grepcut.com/en/tools/crop-video) - trim the frame to a region or aspect ratio. - [Video Trimmer](https://grepcut.com/en/tools/video-trimmer) - cut your clip to length before resizing. - [Compress Video](https://grepcut.com/en/converters/compress-video) - shrink the file size for upload.