How to Export 21:9 Ultrawide Video in Kdenlive

Exporting cinematic, ultrawide video requires adjusting both your project settings and your final render profile. This guide provides a straightforward, step-by-step walkthrough on how to configure Kdenlive to successfully output videos in a 21:9 aspect ratio, ensuring your content looks seamless on ultrawide monitors without unwanted black bars.

Step 1: Create a 21:9 Project Profile

Before configuring your render profile, your Kdenlive project must be set to an ultrawide resolution. If your project is in a standard 16:9 format, rendering in 21:9 will stretch or distort the video.

  1. Open Kdenlive and go to Project > Project Settings in the top menu.
  2. Click the Manage Project Profiles icon (the small gear/document icon on the right).
  3. Click the Create New Profile (plus) icon.
  4. Set the profile parameters to the following values:
    • Frame size: 2560 x 1080 (for 1080p ultrawide) or 3440 x 1440 (for 1440p ultrawide).
    • Frame rate: Select your preferred frame rate (e.g., 24, 30, or 60 fps).
    • Pixel aspect ratio: 1:1 (square pixels).
    • Display aspect ratio: 64 and 27 (64:27 is the true mathematical ratio for 21:9).
  5. Give the profile a name (e.g., “Ultrawide 1080p”) and click Save.
  6. Select your new profile from the list and click OK to apply it to your project.

Step 2: Configure the Render Profile

Once your project timeline is set to the correct aspect ratio, you must set up the export settings to match.

  1. Click the Render button in the top toolbar (or press Ctrl + Enter).
  2. Select your preferred output format from the list (e.g., MP4-H264/AAC is recommended for general use).
  3. In the Render dialog window, look at the options on the right side. Ensure that the Rescale checkbox is unchecked. Unchecking this option forces Kdenlive to output the video at the native resolution specified in your project settings (which is your custom 21:9 profile).
  4. If you need to scale the video down or up during export, check the Rescale box and manually enter your desired 21:9 resolution (e.g., 2560x1080).

Step 3: Create a Custom Render Preset (Optional)

If you want to save these specific encoding settings for future projects, you can generate a permanent render preset.

  1. In the Render dialog, select your base format (like MP4) and click the Create New Profile icon.
  2. Name the group and profile (e.g., “MP4 Ultrawide”).
  3. In the Parameters box, you will see the FFmpeg command line arguments. To lock in the 21:9 aspect ratio, ensure the video size arguments are correct. You can append or edit the arguments to include: s=2560x1080 aspect=2.3703
  4. Click OK to save the preset. This custom profile will now be available in your render menu for future use.