A video that fills the whole TikTok screen looks native. One with black bars looks like a repost. The difference is the size you export at, and it takes a minute to get right.

The size to use

9:16, 1080 by 1920 pixels. That is the full-screen vertical shape on a phone. Aspect ratio means width to height: 9:16 is nine units across for every sixteen tall.

Use these as your defaults:

  • Aspect ratio: 9:16
  • Resolution: 1080 x 1920
  • Orientation: vertical, shot or reframed upright

TikTok accepts other shapes. A horizontal 16:9 video plays in a small strip in the middle of the screen, and a square one sits with space above and below. Both work, but neither gets the full-screen impact. For current upload limits on file size and length, check TikTok's own help pages, because they change.

One recording reframed three ways: vertical, square and widescreen.

The tracking behind a face-aware crop is Apple's Vision framework, detecting on the device so the frame can follow a speaker with no server in the loop.

Where a platform publishes hard numbers, prefer those to folklore: YouTube documents Shorts as up to 3 minutes long and uploaded at a maximum of 1080p.

Keep clear of the edges

TikTok lays its interface over your video. The caption and account name sit near the bottom, the like and share buttons run up the right side, and a bar sits across the top. Anything important under those areas is hard to read.

A simple rule:

  • Keep your subject's face in the middle third of the screen.
  • Put captions in the lower middle, above the app's own caption area, not at the very bottom.
  • Leave a margin at the sides and top for any on-screen text.

Preview on a real phone before posting. The safe area differs a little between devices.

Reframing a horizontal clip

If you filmed sideways, do not letterbox it. Reframe it to 9:16 so the subject fills the frame:

  1. Open the clip and choose the 9:16 vertical option.
  2. Position the crop on the person or the action. A face-aware reframe follows the subject for you, and you can move it by hand.
  3. Check each shot, because a crop that frames one scene well can cut off the next.
  4. Export with the TikTok preset.

In Zella, Make Vertical reframes to 9:16 around your face in one tap on iPhone and Mac, and the export panel has TikTok, Reels, Shorts and YouTube presets. The full per-platform list is in best video size for each platform, and the Reels version is in Instagram video size.

Check it on a phone

Before you post, export the video, send it to your phone and play it full screen. Look at where your face and your captions land against the buttons. If anything is covered, nudge it in the edit, export again and recheck. One round of this catches most problems.

Length and quality

Higher resolution does not rescue a poor clip, and TikTok recompresses what you upload. Start from a sharp, steady source, and export at 1080 x 1920. Free exports in Zella run up to 2 minutes at 1080p with no watermark. For ideas on how long a video should be, see how long should a TikTok, Reel or Short be.

Frequently asked questions

What is the best size for a TikTok video? 1080 x 1920 pixels, a 9:16 vertical shape.

Can I upload a horizontal video to TikTok? Yes, but it plays in a narrow strip. Reframe it to 9:16 for full screen.

Does TikTok crop videos? It can, when the shape does not match the screen. Exporting at 9:16 avoids surprise crops.

Where should captions go on a TikTok video? In the lower middle, above TikTok's own caption area and away from the right-hand buttons.

Does Zella export for TikTok? Yes, on Mac and iPhone, with a 9:16 reframe and a TikTok export preset.