Free tool · No sign-up
Resize Video for TikTok, Reels & YouTube
Convert any clip to 9:16, 1:1, 4:5 or 16:9. Crop and position it, or fit it on a blurred or solid background. It all happens on your device.
Aspect Ratio Converter
Reframe a video for TikTok, Reels, Shorts or YouTube.
Drop a video here
MP4, MOV or WebM. It never leaves your device.
Aspect ratio
Fit
Position (left / right)
Add a video to position the crop.
How to change a video’s aspect ratio
- 1. Add a video. Drop an MP4, MOV or WebM file onto the converter, or tap Choose file.
- 2. Pick a shape and fit. Choose 9:16, 1:1, 4:5 or 16:9. Crop fills the frame and lets you slide the framing; Blur fill and Color fill keep the whole picture with a background behind it. The preview shows exactly what you will get.
- 3. Convert and download. Press Convert, then download the MP4, ready to upload. Free, no watermark.
More free video tools
- Video Trimmer to cut the start and end of a clip.
- Video Compressor to shrink a video for Discord or WhatsApp.
- GIF Maker to turn a clip into a GIF.
- Frame Extractor to save any frame as a JPG.
Frequently asked questions
- How do I resize a video for TikTok or Reels?
- Add your video, choose 9:16, then pick Crop to fill the screen (slide the position to keep your subject in frame) or Blur fill to keep the whole shot with a blurred background. Press Convert and download the 1080×1920 MP4 (smaller if your source is smaller).
- What is the difference between crop, blur fill and color fill?
- Crop zooms in until the frame is filled and trims the edges, so nothing is letterboxed but some of the picture is cut. Blur fill shrinks the whole video to fit and fills the empty space with a blurred copy of it. Color fill does the same with a solid color you choose.
- Which aspect ratio should I use for each platform?
- 9:16 for TikTok, Instagram Reels, YouTube Shorts and Stories. 4:5 for Instagram feed posts that take up the most screen. 1:1 for square feed posts. 16:9 for regular YouTube videos and landscape players.
- Is my video uploaded anywhere?
- No. The conversion runs in your browser with nothing sent to a server, so your footage stays on your device. Signed-in users can optionally save the result to their FXI Studio library.
- Will it lower the quality or add a watermark?
- There is no watermark. The video is re-encoded to H.264 at a high quality setting, and the output is 1080 pixels on its short side unless your source is smaller, so it never upscales a small clip needlessly.