Safe Zone Checker

Almost every safe zone template floating around design forums is a single rectangle copied from a 2021 TikTok ad spec. Two things have changed since. The action rail has grown, most obviously on Shorts, where six stacked controls now claim close to a sixth of the frame width. And the bottom block is no longer a fixed height: it expands with the caption, so the same layout that survives a four-word caption gets swallowed by a two-line one. If you are checking against a static rectangle, you are checking against the best case.

The more useful correction is to stop designing per platform. If one export goes to TikTok, Reels and Shorts — which it does for almost everyone working at volume — the only rectangle that matters is the intersection of all three, and it is meaningfully smaller than any of them individually. Roughly 79% of the width and 57% of the height, centred slightly high. Design inside that and you never think about it again. Design inside TikTok's box alone and Reels will cover your lower third about a third of the time.

One thing this tool cannot check for you: the platforms crop before they obstruct. Upload a 4:5 or 16:9 file and the app fills the frame rather than letterboxing it, so your carefully placed lower third may already be off-screen before any interface appears. Export true 9:16, check the frame, then worry about the overlay. In that order the safe zone is a five-minute problem rather than a re-edit.