Checking caption length and on-screen safe zones
Type your caption and this tool checks its length against TikTok, Instagram Reels, and YouTube Shorts caption limits, while the preview below shows an approximate mock-up of where each platform's interface elements - like/comment/share icons on the right, username and caption bar at the bottom - typically sit on a vertical video. Overlapping those zones with on-screen text in your actual video (not just the caption field) is a common mistake worth checking before you publish.
Why caption limits differ so much between these three platforms
TikTok and Instagram Reels both allow long captions (up to 2,200 characters) since their feed design shows captions as expandable text below the video, while YouTube Shorts inherits its description field's conventions but displays far less of it before truncating in the Shorts feed specifically - the same general idea (a caption field) ends up with very different practical limits depending on how each platform's interface actually presents it.
Why the safe-zone preview matters separately from the caption character count
A caption can be well within the character limit and still cause a problem if your video's own on-screen text or graphics sit underneath where the app's interface overlays its icons and username bar - checking both the caption length and the safe zones catches two genuinely different kinds of mistake that can each hurt a video's performance independently.
Why this preview is described as approximate rather than exact
Each platform's interface layout isn't fixed forever - spacing, icon placement, and even which elements appear can shift with app updates, and can vary slightly between devices. Treating the preview as a representative approximation rather than a pixel-perfect simulation keeps expectations accurate: it's built to help you avoid the most common overlap mistakes, not to guarantee an exact match to any one app's current build.