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Post Preview: See How Your Video Looks on TikTok, Reels & Shorts Before You Post

Drop in a clip and watch it sit inside a real phone — exactly how it lands on TikTok, Reels, and Shorts

Reel Video Captions

Open Post Preview →

Post Preview shows you exactly how your captioned video will look as a TikTok, Instagram Reel, or YouTube Short — the feed-thumbnail crop and the caption safe-zones — before you publish. Drop in a vertical video, switch between platforms, and see your captions rendered behind the real platform interface so nothing important gets covered after you post.

Quick answer: To see what your video will look like before posting on TikTok, Instagram Reels, or YouTube Shorts, run it through a safe-zone checker — a tool that overlays each platform’s real interface (the username, caption, sound row, and the right-side like / comment / share buttons) on top of your video so you can confirm your captions and hook sit in the visible “safe zone” and are not covered. Post Preview does this free, in the browser, with no sign-up: drop in the clip, switch between TikTok, Reels, and Shorts, and reposition captions if anything collides before you publish.

Post Preview showing a captioned clip inside the TikTok For You interface: the platform selector (TikTok, Instagram Reels, YouTube Shorts) on the left, and a phone preview where the burned-in caption sits clear of TikTok's right-side action rail (like 328.4K, comment 1,204, bookmark 4,521, share 2,301) and the @creativestudio username, caption, and sound row at the bottom — so the caption safe zone is verified before publishing

The problem Post Preview solves

You burn captions into a video, it looks perfect in your editor, you upload it to TikTok — and the bottom line of every caption is sitting behind the username and the “Add comment” bar. The right edge of your text is under the like and share buttons. The hook you wrote got cropped out of the feed thumbnail.

None of that is visible in a normal video player, because the player does not draw TikTok’s interface on top of your video. The platform UI only appears once the clip is live. By then the fix is: delete the post, re-edit the caption position, re-export, re-upload, and lose the early engagement window.

Post Preview removes that loop. It draws the actual platform chrome over your video before you publish, so you catch the collision while it is still cheap to fix.

How it works

  1. Open Post Preview and drop in your vertical video (the captioned export, or the clip you are about to caption).
  2. Pick a platform: TikTok, Instagram Reels, or YouTube Shorts.
  3. The video renders with that platform’s real interface overlaid — username, caption row, audio attribution, action buttons, and progress bar.
  4. Toggle the feed-thumbnail view to see how the profile grid and feed crop your frame.
  5. If a caption collides with UI or the hook falls outside the thumbnail crop, reposition the captions and re-check. When it is clean on all three platforms, publish with confidence.

It is free, runs in the browser, needs no sign-up, and adds no watermark.

Caption safe-zones by platform

Each platform places its interface differently, so a caption that is safe on one surface can be covered on another. Post Preview lets you check all three on the same upload.

  • TikTok — the right-side action rail (profile, like, comment, bookmark, share, sound) covers the right edge; the username, caption, and “Add comment” bar cover the bottom band. Keep captions centered and clear of the lower third and the far-right column.
  • Instagram Reels — a bottom row holds the username, caption, and audio title; right-side buttons mirror TikTok’s rail. The safe area is the upper and central portion of the frame.
  • YouTube Shorts — adds a bottom title and channel/subscribe row plus right-side controls, so the unsafe bottom band is typically taller than on TikTok. Center-frame captions are safest.

Post Preview set to Instagram Reels: the platform selector on the left with Instagram Reels active, and a phone preview showing the Reels interface — the Reels and Friends tabs up top, the right-side action rail (12,847 likes, 342 comments, share, more), and the @creativestudio username with a Follow button, caption, and original-audio row across the bottom, marking the Reels caption safe zone before publishing

Because the exact overlay shifts with app updates and device size, Post Preview renders the current interface rather than asking you to memorize fixed margins.

When to use it

Use Post Preview on every clip before it goes out — especially when you are cross-posting the same captioned video to TikTok, Reels, and Shorts at once, since one caption position has to survive three different interfaces and three different thumbnail crops. It is the last check between “captioned” and “published.”

Frequently asked questions

What is a caption safe zone on TikTok, Reels, and Shorts?

A caption safe zone is the area of a vertical video that stays visible and is not covered by the platform's interface — the username, caption text, music title, like/comment/share buttons, and progress bar. On TikTok the right-side action rail and the bottom username/caption block overlap roughly the lower third and right edge of the frame. Instagram Reels covers a similar bottom band plus right-side buttons. YouTube Shorts adds a bottom title and channel row plus right-side controls. Captions placed outside these zones stay readable; captions inside them get hidden behind UI.

Why are my captions cut off or covered on TikTok?

Captions get covered on TikTok when they are burned into the bottom third or far-right of the frame, where TikTok overlays the username, caption, sounds, and the like/comment/share/bookmark buttons. The video itself is fine — the platform UI sits on top of it during playback. Post Preview shows your captioned video with the actual TikTok interface overlaid so you can see the collision before publishing instead of after.

How do I preview a Reel before posting it?

Open Post Preview, drop in your captioned video, and switch the overlay to Instagram Reels. You will see the video cropped to the Reels feed thumbnail and rendered with the Reels interface — bottom caption row, audio attribution, and right-side action buttons — so you can confirm your captions and hook stay visible before you upload to Instagram.

Does the feed thumbnail crop my video differently than playback?

Yes. TikTok, Reels, and Shorts all crop a vertical video to a tighter aspect ratio for the profile-grid and feed thumbnail, which can chop off a hook line at the top or bottom that is fully visible during normal playback. Post Preview shows the thumbnail crop separately from the full-playback view so you can keep your hook inside the thumbnail-safe area.

Is Post Preview free and does it require sign-up?

Post Preview is completely free, requires no sign-up, no credit card, and adds no watermark. It runs in your browser as part of Reel Video Captions. You can preview as many videos as you want with no usage cap.

Do I need to caption my video with Reel Video Captions to use Post Preview?

No. Post Preview works on any vertical video file, whether the captions were burned in by Reel Video Captions or by another tool. It overlays the platform UI on whatever video you upload so you can check safe zones and the thumbnail crop regardless of how the captions were made.

Which platforms does Post Preview support?

Post Preview supports the three main short-form surfaces: TikTok, Instagram Reels, and YouTube Shorts. You can switch between each platform's interface overlay and feed-thumbnail crop on the same uploaded video, since each platform places its UI and crops its thumbnail differently.