and post dimensions for 2026Threads publishes no recommended size, so 1080 × 1350 (4:5) is the common default for photos and 1080 × 1920 (9:16) for video. Scheduled posts must fit the API: JPEG or PNG, up to 8 MB, 320 to 1,440 px wide.
Checked on against 5 sources.
Threads does not publish a recommended image size. Its API, which every scheduler uses, takes JPEG and PNG images up to 8 MB and 320 to 1,440 px wide, in any shape up to 10:1. Images outside that width range are scaled.
So size for the phone screen: 1080 × 1350 (4:5) for photos and carousels, 1080 × 1080 for squares, and 1080 × 1920 (9:16) for vertical video, the ratio Meta's API docs recommend. A carousel takes 2 to 20 items through the API, photos and videos mixed.
The API added spoilers for text, image and video posts, so scheduled posts can use them too. Source
The API began to take carousels of up to 20 images, videos, or a mix of the two. Source
Scheduled images and videos can carry alt text, up to 1,000 characters each. Source
It is the common size for photos and carousels, and it also fits Instagram's API, so one export works on both.
They are the formats Meta officially supports for Threads images, and 8 MB is the API's cap.
The API scales images outside that range. 1080 px wide is a safe export.
Meta's docs recommend 9:16 for Threads video, at most 1,920 px wide.
A carousel can hold both, in any order. Through the API it takes 2 to 20 items.
Alt text describes an image or video for screen readers. Through the API it takes up to 1,000 characters.
Every limit on this page comes from Meta's Threads API documentation, read on October 17, 2026. Threads publishes no recommended pixel size for posts or profile photos, so the sizes in the tables are the common ones and are labelled that way. Where Threads states no number for the app, the page says "Not published".
