ABOUT
About Short-form Preflight
A small, browser-only tool for one specific problem: does this subtitle placement survive being posted to three different platforms?
The problem
Short-form video creators routinely post the same clip to YouTube Shorts, Instagram Reels and TikTok. Each platform draws its own UI — action icons, captions, usernames — over the video in a slightly different layout. A subtitle positioned to clear one platform's UI can still end up under another's. Checking that by eye, one platform at a time, is slow and easy to get wrong. Short-form Preflight checks one placement against all three at once and tells you exactly which region it conflicts with, if any.
How it's built
Everything runs in your browser. Local media you choose is read with the browser's File API and rendered through a local Object URL and canvas — it's never uploaded anywhere, because there's nowhere for it to go: this is a static site with no server, no database, and no account system. See Privacy for the full detail.
What it covers today
Right now, the tool centers on one user element: a single, shared Subtitle rectangle, checked against Shorts, Reels and TikTok simultaneously. It's not yet a general caption editor or a multi-element layout tool — see FAQ for specifics on what is and isn't supported.
Evidence-based reference regions
The reference regions the tool checks against aren't guesses. Each one is tracked with where it came from, how confident we are in it, and whether it's currently trusted enough to drive a result — see the platform guides for what's actually behind each platform's reference. A synthetic demo dataset also exists purely so you can try the tool without waiting on real evidence; it's labeled as demo data everywhere it appears and never presented as verified.
What it isn't
This is an independent tool, not an official product of YouTube, Meta/Instagram, or TikTok, and it isn't affiliated with or endorsed by any of them. It doesn't guarantee how your content will render on every device, app version, or account — it checks against the specific evidence it currently has, and says so plainly when that evidence is incomplete.