Threads Image Sizes 2026: What Meta Documents and What to Test

Meta’s public Threads help explains how to attach a photo or video. It does not, in the source checked for this guide, publish one universal pixel size for a Threads image.

That makes many confident “best Threads dimensions” tables harder to defend than they look. A useful guide should identify the uncertainty and give you a reliable test method.

What Meta currently documents

Meta’s start a new thread guidance says a thread can include text, links, photos, videos, or a combination. The composer lets you add media from your gallery and control who can reply and quote.

It also notes a fediverse boundary: media shared to other servers may be displayed differently because those servers can have their own limitations.

The cited page does not state:

• a mandatory photo width;
• a recommended 4:5 canvas;
• a guaranteed carousel count;
• a fixed link-preview pixel size;
• a universal media safe zone.

This guide therefore does not repeat those claims as platform requirements.

Use a square as a controlled test

A 1080 × 1080 square is a sensible starting asset because it is simple to inspect and does not depend on a narrow landscape crop. It is not presented here as Meta’s official optimum.

For a square post:

1. Keep the subject away from the edges.
2. Make text readable at phone width.
3. Export the file and inspect it outside the editor.
4. Add it to the Threads composer.
5. Check the feed preview before publishing.

Image for Post can create a 1080 × 1080 PNG without signup. It does not include a Threads-specific crop, preview, scheduler, or carousel builder.

Portrait and landscape assets

Threads may display other orientations, but the absence of a public fixed-size rule means the composer is your final check.

Use a portrait image when the subject genuinely benefits from vertical space, not because a third-party article promises more engagement. Use a landscape image for wide material that remains legible in the feed.

When reusing an Instagram asset, do not assume the two services will render it identically. The posting context, surrounding text, and federation destination can differ.

Multiple images

Treat a multi-image post as a sequence:

• make the first image understandable on its own;
• use consistent spacing and type across the set;
• avoid putting a sentence across two images;
• inspect each crop in the composer;
• verify the order after attaching the files.

Do not rely on a Threads-specific carousel tool in Image for Post. It exports individual files, and Threads controls the arrangement.

Accessibility and content fit

The image should add information, not merely repeat the first line of the post. Keep essential wording in the post text when possible so it remains available if the image is cropped, fails to load, or is displayed differently on another server.

If Threads offers alternative-text controls in your current posting flow, use them. Interface availability can change, so check the composer rather than relying on a static tutorial.

A safe publishing workflow

1. Create the asset at a known ratio.
2. Export and check the real file.
3. View it at a small size.
4. Upload it to Threads.
5. Inspect every media item and the post text together.
6. Publish only after the composer shows an acceptable crop.
7. Review your own post results before standardising a format.

Create a square test asset

Open Image for Post to create a 1080 × 1080 PNG without signup. This is a practical test canvas, not a claim that Meta has selected it as the optimal Threads size.

Source checked

• Meta Help: start a new thread on Threads

The source and product behavior were checked on 29 July 2026.