Why this is not published
Platforms do not generally publish exact safe zone measurements, because their interfaces change and vary by device, notch size and app version.
That means every safe zone figure you find anywhere - including ours - is a measurement someone took from the interface, not an official specification. Treat them as close approximations with a margin, not exact boundaries.
How much is actually covered
On TikTok and Instagram Reels, expect roughly the bottom third to be occupied by the caption, the audio label and the vertical action stack, plus a strip at the top.
Snapchat Spotlight reserves generous margins at both top and bottom. YouTube Shorts is far lighter - mainly the subscribe row and progress bar. LinkedIn and X cover almost nothing.
The side margins matter too: the action buttons on TikTok and Reels run down the right edge, so anything within about 6% of that side is at risk.
Designing around it
Keep every essential element - faces, on-screen text, product, logo - inside the middle band. The centre 1:1 square of a 9:16 frame is a reliable rule of thumb that works on all of them.
Do not simply shrink your content to fit. Reframe the shot so the subject occupies the safe area naturally; letterboxed or tiny-in-the-middle content reads as repurposed and performs worse.
Check with an overlay before exporting rather than after posting. It takes seconds and saves a re-upload that loses your early engagement window.
The short version
Design for the most aggressive overlay - TikTok or Reels - and your framing is safe on every other platform. Verify with an overlay before you export, not after you post.