Free online video resizer
Resize video online for free
Use this free online video resizer to resize videos for TikTok, Reels, YouTube Shorts, Instagram, YouTube, square posts, and widescreen workflows with crop, blur background, or solid background fill.
Free online video resizer
Upload a video, choose the final canvas size, decide how the source should fit, and export a new MP4 from your browser without creating an account.
Resize preview
Resize settings
Upload a video to unlock resize settings and export.
Built for platform size changes
The resize workflow changes the final canvas for TikTok, Reels, Shorts, Instagram, or YouTube. Blur background is recommended when you want to keep the full video visible.
Browser export is not available
This tool needs a modern Chromium browser with WebCodecs support to export MP4 files.
Choose the final canvas size for your platform.
Blur background keeps the full clip; crop fills the frame by trimming edges.
How it works
Resize a video in three quick steps
Upload your video
Choose an MP4, WebM, or MOV file from your device. The tool reads and previews it in your browser.
Choose output size
Select 9:16, 1:1, 4:5, 16:9, or original and decide whether to crop, blur the background, or use a solid fill.
Export MP4
Download a resized MP4 in 720p or 1080p for free, ready for social publishing or another editing workflow.
Resize settings
Resize video without opening a full editor
Use free quick presets when you only need to change the final aspect ratio before publishing.
Blur background
Keep the full source video visible and fill unused space with a soft blurred version of the same frame.
Crop to fill
Fill the selected aspect ratio by cropping edges. This works best when the subject is near the center.
Solid background
Place the source video on a clean color background when you want a simpler layout.
Platform sizes
Resize video for TikTok, Reels, Shorts, Instagram, and YouTube
Pick the output frame that matches your destination before downloading the MP4.
9:16 vertical video
Resize for TikTok, Instagram Reels, and YouTube Shorts with a vertical canvas.
1:1 and 4:5 social posts
Use square or feed-friendly formats when your video needs to fit Instagram and social grids.
16:9 widescreen
Resize for YouTube, website embeds, presentations, and horizontal social posts.
Browser notes
A free resizer for quick video format changes
Runs in your browser
The free resizer uses browser-side video APIs and does not send your file to a rendering server.
Best for short clips
Browser export works best with short social clips. Very large videos can be slower or run out of memory.
Simple resize presets
V1 focuses on fixed aspect ratios and simple fill modes. For AI reframing, continue in CaptionBolt.
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Next video workflow
Resize, crop, caption, or create social clips
Use these related tools when resizing is part of a larger publishing workflow.
Crop video online for free
Crop video online for free in your browser. Upload MP4, WebM, or MOV files, drag and resize the crop box, then export the selected area as MP4.
Auto Subtitle Generator for Videos
Generate AI subtitles and captions for videos. Create captioned clips for Shorts, Reels, TikTok, podcasts, and interviews with CaptionBolt.
Turn long videos into captioned short clips
Turn long videos into captioned clips for Shorts, Reels, and TikTok with CaptionBolt. Repurpose YouTube videos, webinars, courses, podcasts, and livestreams faster.
Free online video and subtitle tools
Use CaptionBolt's free online tools to convert subtitles, edit captions, crop video, resize video, and export browser-ready files without installing software.
Need captions or smarter reframing?
Turn resized clips into captioned short videos
This resizer is free for quick browser edits. CaptionBolt helps creators add AI subtitles, style captions, reframe clips, and export platform-ready videos when they need the full workflow.
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