The short answer
| Format | Size in pixels | Best for |
|---|---|---|
| 9:16 | 1080 by 1920 | Full screen TikTok slideshows (the default) |
| 3:4 | 1080 by 1440 | TikTok photo mode that keeps the whole photo in view |
| 4:5 | 1080 by 1350 | Instagram feed carousels |
Which one should you use?
Use 9:16 at 1080 by 1920 for almost everything on TikTok. It fills the whole phone screen, which is what the For You page is built for. Use 3:4 when a photo would lose too much at 9:16. Use 4:5 when the same slides are going to an Instagram carousel.
How many photos can a TikTok slideshow have?
Up to 35 photos in one post. Most viral slideshows use 5 to 8.
Mind the parts TikTok covers
Size is only half of it. TikTok draws its tabs, buttons and caption on top of your slides, so text near the edges gets covered. Read the safe zones guide for the exact areas.
Or skip the math
Slidemate exports every slide at the right size for its format, 1080 by 1920 by default, and keeps text out of the areas TikTok covers. You pick a format once; every slide follows.
Updated October 1, 2026