Most often because the photos were not all the same size. TikTok only accepts a photo post when every photo has the exact same width and height in pixels. Export every photo at one size, such as 1080 x 1920, and schedule it again.
Same size, not just same shape
- This is not about shape. Three tall 9:16 photos can still fail together.
- 1080 x 1920 and 1440 x 2560 are the same shape but different sizes. TikTok refuses that set.
- One odd photo fails the whole post.
What sprkly does about it
- Before a TikTok photo post goes out, sprkly makes every photo the same size.
- It scales each one to fit and pads the edges. It never crops, so no part of your photo is lost.
- It also turns each photo into a JPEG, which TikTok needs.
- If sprkly cannot measure every photo, it leaves the set alone. That set can still fail.
How to fix it
- Export every photo at the same size. 1080 x 1920 is the safe choice.
- Save them as JPEG.
- Open the failed post, swap in the new photos, and pick a new time.
Other reasons a photo post fails
- Wrong file type. TikTok refused the format. Re-export as JPEG.
- Too many photos. TikTok takes up to 35 in one post.
- Connection expired. Reconnect TikTok in Settings, then reschedule.
One more TikTok photo rule
- A photo post title holds up to 90 characters. sprkly cuts a longer one to fit, so check how it ends.
- Your longer text goes in the description.
How to catch it before it posts
- Compose checks your photos as you add them.
- If they are different sizes, it warns you before you schedule.
Do it in sprkly: In Compose, add your TikTok photos and read the size warning. If one shows, re-export the odd photo at the same size as the rest.
Docs: sprkly docs