Threads runs on the same infrastructure as Instagram, and it shows in the image specs. A photo sized correctly for an Instagram feed post will drop into a Threads post without any surprise cropping, which makes this one of the easier platforms to get right if you’re already posting to both.
Here are the dimensions Threads actually uses.
| Type | Size | Aspect ratio |
|---|---|---|
| Profile Photo | 320 x 320 | 1:1 |
| Square Post | 1080 x 1080 | 1:1 |
| Portrait Post | 1080 x 1350 | 4:5 |
| Landscape Post | 1080 x 566 | 1.91:1 |
| Multi-Image Post | 1080 x 1080 | 1:1 |
Which size to actually use
Portrait at 1080 x 1350 is the strongest default for a single-image post, the same way it is on Instagram. It takes up more of the screen while someone scrolls, which holds attention a beat longer than a square image does. Square at 1080 x 1080 is the safer choice for a multi-image post, since Threads displays those in a more even grid than it does portrait images.
Landscape posts at 1.91:1 work but read smaller in the feed, keep those for content where the wide shape is doing real work, like a screenshot or a chart, rather than a photo that would look better tall.
Format and common mistakes
Export as JPEG for photos and PNG when you need transparency or sharp text. If you’re cross-posting the same image to Instagram and Threads, size it once at 1080 x 1350 and reuse it rather than exporting twice, the specs match closely enough that a single export covers both. A social media image resizer makes that a one-step job.
The most common mistake is posting a screenshot at whatever odd ratio it was captured in and letting Threads crop it. Run it through a Threads image size checker first if you’re not sure it’ll display cleanly, and lean on the social media image size guide if you’re juggling more than one platform’s specs at once.
Keep file size reasonable too. A image compressor brings a large export down without a visible hit to quality, which matters more on a slower connection than most people account for.