Square and vertical Shorts series episodes: allowed, keep one size

YouTube allows both square and vertical episodes in one Shorts series, since its page says the videos "must be portrait or square in dimension and have a maximum duration of 180 seconds". That is a rule about eligibility, not about taste: render a whole season at one Sume Timeline output size, such as 1080x1920, so viewers swiping through the series feed see a steady frame.

The rule is on Create shows from your videos (read 2026-10-06). The page also says viewers who find an episode get a "watch series" button that opens a feed they can swipe through vertically.

What does eligibility look like per episode?

The figures are laid out below.

Why pick one size per season?

This part is a recommendation, not a YouTube rule. A square episode between vertical ones changes the picture area in the swipe feed, and burned-in captions placed for one shape sit wrong in the other. One output object reused for every episode also keeps your render bodies identical apart from the content.

In Timeline 1.0, omit output for the 1080x1920 default, or set both width and height as even integers between 256 and 2160. Details are in the Timeline 1.0 docs.

What if one episode really must be square?

Then render that episode with output.width 1080 and output.height 1080, and set the slots' fit to contain or blur if the footage is vertical, so nothing important is cropped. Move any burned-in captions to suit the new frame. The series still qualifies, because square is allowed.