1. Accepted files
| Accepted | Not accepted | |
|---|---|---|
| Photos | JPG / JPEG, PNG, WEBP | GIF, SVG, PDF, HEIC and anything that is not a real photo |
| Videos | MP4, M4V, MOV | Other video formats |
| Size | Up to 500 MB per file | Empty files, and files over 500 MB |
Postalu reads the first bytes of each file to confirm what it really is. Renaming program.exe to clip.mp4 does not work. A rejected file is listed with its reason, for example is a Windows program, not a photo or video, is a GIF, which these platforms don't accept or isn't a supported photo or video (JPEG, PNG, WebP, MP4 or MOV).
TikTok photo posts accept JPG and WEBP only, so a PNG fails there with TikTok photo posts accept JPG or WEBP images only. X photos can be JPG, PNG or WEBP.
2. Checks that run in the page
The composer reads each file's length and shape before you publish. Errors (red ✕) block publishing. Warnings (amber ⚠) only inform, because the limit differs by account.
| Platform | Blocks (error) | Warns |
|---|---|---|
| Threads | Video over 5 minutes | |
| Instagram Story | Video over 60 seconds | File that is not 9:16 |
| Instagram photo or carousel image | Shape outside 4:5 to 1.91:1: Instagram photos must be between 4:5 and 1.91:1… Crop it first. | |
| Instagram Reel | Over 15 minutes, under 3 seconds, or not 9:16 | |
| Facebook Story | Video over 2 minutes, or not 9:16 | |
| TikTok | Video over 10 minutes (your account's real limit is checked when you publish) | |
| X | Video over 2:20 unless the account has X Premium | |
| Video over 10 minutes may be rejected | ||
| Any platform | File over 500 MB, empty or damaged. Media file is empty or corrupted. / File is larger than the 500MB size limit. |
Tags next to the file show its type, size, dimensions, length and aspect ratio. A 9:16 file is marked as optimized for Reels and TikTok.
3. Fixing a blocked file
- Too long: trim it in your editor, or untick the platform that has the limit (for example untick Threads for a 7-minute video).
- Wrong shape for Instagram: crop the photo to between 4:5 (portrait) and 1.91:1 (wide).
- Too large: export at a lower bitrate.
- Not a real photo or video: export it again as JPG, PNG, WEBP, MP4 or MOV.
Read next
- Carousels and slideshows Post 2 or more photos together, set the cover and the order, and know each platform's maximum.
- What each platform supports Photo, video, carousel, Story, first comment and text limits for every platform side by side.
- Video thumbnails, Reel covers and photo alt text Choose a YouTube thumbnail, an Instagram Reel cover frame or image, and add alt text to Instagram photos.
- Messages when you press Continue, Review or Publish The checks Postalu runs on a post before it is sent, with the exact message for each.
