For: all plans
Next to Render Movie (or Render to MP4 on a scene), pick:
New videos start at 1080p and 30 fps, and Explaindio remembers your choice for each movie and scene.
When you download: if you picked 720p or 24 fps, the download is that size, while the preview on the page plays the full-size video. Right after a render, you may see "Making your 720p, 30 fps file…" for a moment. If that file isn't ready yet, the download is the full-size 1080p, 30 fps video.