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Aspect Ratio Converter is a free, in-browser tool that reframes a video to 9:16, 1:1, 4:5, or 16:9. Crop fills the frame, Blur fill keeps the whole shot over a blurred copy, and Color fill keeps the shot over a solid color. The output is an H.264 MP4 at 1080 pixels on the short side, with no watermark.

Best for

  • convert video to 9:16
  • resize video for Reels
  • horizontal to vertical video
  • blur background vertical video

What is Aspect Ratio Converter?

Aspect Ratio Converter turns a video made for one placement into another, for example a 16:9 clip into a 9:16 vertical for Reels, Shorts, or TikTok. It runs in your browser with no upload and no account.

The video is re-encoded to H.264 at high quality. Output is 1080 pixels on its short side, or smaller if the source is smaller, so a small clip is never upscaled.

What can you do with Aspect Ratio Converter?

Four target ratios
9:16, 1:1, 4:5, and 16:9.
Crop
Fill the frame, with a position slider to keep your subject in view.
Blur fill
Fit the whole shot over a blurred copy of itself.
Color fill
Fit the whole shot over a solid color you pick.
Clean output
H.264 MP4 at up to 1080 pixels on the short side, no watermark.

How do you use Aspect Ratio Converter?

  1. 1
    Open the converter. Go to /aspect-ratio-converter. No account is needed.
  2. 2
    Add a video and pick a ratio. Choose 9:16, 1:1, 4:5, or 16:9.
  3. 3
    Choose a fit. Pick Crop, Blur fill, or Color fill, and adjust the crop position if needed.
  4. 4
    Convert and download. Convert and download the MP4.

What do people ask about Aspect Ratio Converter?

Is there a watermark?
No. The converted video has no watermark.
What resolution is the output?
1080 pixels on the short side, for example 1080×1920 for 9:16, or smaller if your source is smaller.
Can I keep the whole frame instead of cropping?
Yes. Blur fill and Color fill fit the entire shot and fill the remaining space.

Concepts & tutorials

Learn the ideas behind Aspect Ratio Converter and see it inside a full AI filmmaking workflow.

Key concepts

Tutorials

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Try Aspect Ratio Converter

Free and in your browser, no account needed to start.

Open Aspect Ratio ConverterAll documentation