How to Change Project Aspect Ratio in Kdenlive

Changing your project’s aspect ratio in Kdenlive during an active editing session is a straightforward process that does not require starting a new project from scratch. Whether you need to convert a standard 16:9 widescreen video into a vertical 9:16 format for mobile platforms or adjust to a cinematic widescreen ratio, this guide provides a direct, step-by-step method to safely modify your project settings mid-edit and adjust your existing timeline clips to fit the new dimensions.

Step 1: Open Project Settings

To change the aspect ratio, you must modify the project’s video profile. With your project open in Kdenlive, navigate to the top menu bar and click on Project, then select Project Settings from the dropdown menu. Alternatively, you can use the keyboard shortcut Ctrl + Shift + , (on Windows/Linux) to open this window.

Step 2: Select a New Video Profile

In the Project Settings dialog box, ensure you are on the Project Settings tab. Here, you will see a list of pre-configured video profiles categorized by resolution and frame rate. * Browse the categories (such as HD 1080, Ultra HD, or Custom) to find the profile that matches your desired aspect ratio and frame rate. * For vertical video (9:16), look for profiles labeled Vertical HD. * If you cannot find the exact aspect ratio you need, click the Manage Video Profiles icon (the gear icon) to create a custom profile with your specific pixel dimensions.

Once you have selected the appropriate profile, click OK at the bottom of the window. Your project monitor will instantly update to display the new aspect ratio.

Step 3: Adjust Existing Clips to Fit the New Ratio

Changing the project aspect ratio does not automatically resize your existing timeline footage. Depending on the original clip dimensions, your media may now have black bars on the sides (pillarboxing) or at the top and bottom (letterboxing). To fix this:

  1. Select a clip on your timeline.
  2. Go to the Effects tab and search for the Transform effect.
  3. Drag and drop the Transform effect onto the clip.
  4. In the Properties panel, use the Size and X/Y Position sliders to scale and reposition the footage until it fills the new screen dimensions correctly.
  5. If you have multiple clips that need the same adjustment, right-click the adjusted clip, select Copy, then right-click the other clips on your timeline and select Paste Effects.