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Every vertical platform lays its own interface over your video: usernames and captions at the bottom, action buttons on the right, camera controls at the top. Captions placed in those areas get covered. Load a frame from your video (or just use the blank canvas) and toggle each platform’s overlay to see where text is safe.
| Platform | Top | Bottom | Right | What sits there |
|---|---|---|---|---|
| TikTok | 130px | 440px | 140px | Bottom: username, caption text, and sounds row. Right: like/comment/share rail. |
| Instagram Reels | 250px | 420px | 130px | Top: camera and audio chips. Bottom: caption and CTA area. Right: action rail. |
| YouTube Shorts | 120px | 360px | 120px | Bottom: title, channel, and subscribe row. Right: action rail. |
Overlay all three platforms and one band survives: from about 65% to 78% of frame height, centered, staying roughly 140px clear of the right edge. That is the only region where a caption is simultaneously clear of TikTok’s caption stack, Reels’ CTA area, and Shorts’ title row, and it is where SubtitleRocket’s templates place captions by default.
Broadcast and streaming guidelines converge on similar limits: the BBC’s subtitle guidelines target roughly 160-180 words per minute, and Netflix’s English timed-text style guide caps adult subtitles at 20 characters per second (17 for children’s content). For short-form video watched on mute, staying near 12-15 characters per second reads comfortably, which in practice means two to six words per caption at creator pacing. If a line needs a pause to read, split the caption instead of shrinking the font.
Zone numbers: compiled from TikTok, Instagram, and YouTube vertical-format creative guidelines plus app measurements, July 2026; interfaces change with app versions, so re-check before pixel-critical work. Reading speed: BBC Subtitle Guidelines (bbc.github.io/subtitle-guidelines); Netflix Partner Help Center, English Timed Text Style Guide.
They are compiled from the platforms’ own creative guidelines for vertical formats plus our measurements of the current apps (July 2026), on a 1080×1920 frame. Interfaces shift with app versions and caption length, so treat the zones as the reliable envelope, not a pixel contract.
The band between roughly 65% and 78% of frame height is safe on all three platforms at once, which is why SubtitleRocket templates default there. Dead center works too but competes with faces.
The overlays model the full-screen vertical feeds (9:16). Square and landscape posts are letterboxed differently per platform, and feed UI covers proportionally less of the frame.
These utilities handle subtitle files. To generate captions from speech, style them, and burn them into an MP4, open the full editor; free 720p export, no signup to start.
SubtitleRocket