Threads Media Specs and Best Practices 2026

Threads finally got its own image pipeline separate from Instagram in late 2025, and the differences are large enough that "just repost from Instagram" now leaves quality on the table. This guide covers what Threads accepts, how it re-encodes, and the exact numbers you need for cross-posting.

Quick reference

Media type	Aspect ratio	Recommended pixels	Upload max
Single image	1:1 to 4:5 (portrait)	1440x1440 or 1440x1800	20 MB
Landscape image	up to 1.91:1	1440x753	20 MB
Carousel image	1:1	1440x1440	20 MB per slide
Carousel slides	2-20 items	mix allowed	n/a
Video (in-feed)	9:16 or 1:1 or 4:5	1080x1920 (9:16)	1 GB
Video length	up to 5 minutes	n/a	n/a
Profile avatar	1:1	720x720	8 MB
Link preview	1.91:1 (OG image)	1200x630 source	fetched

The Instagram crossover that breaks

Threads and Instagram share account identity but not the image processing pipeline. Instagram Feed images are center-cropped or compressed to a max of 1080 px on the short edge. Threads renders images up to 1440 px. If you compose for Instagram's 1080x1350 portrait and cross-post, Threads upscales to fit, and the result looks soft next to native Threads posts shot at 1440x1800.

The fix is to compose at Threads' native resolution and let Instagram downscale on cross-post. 1440x1800 posted to Threads shows up crisp. Instagram downsizes it to 1080x1350 and quality stays intact because it is coming from a larger source.

Carousel limits

Threads carousels hold up to 20 items in April 2026 (up from 10 through most of 2025). A few things that trip people up:

• All slides share one caption. You cannot caption slides individually. The first image's alt text is what screen readers announce for the post overall, unless you set alt per slide.
• Mixed aspect ratios are allowed, but the first slide sets the viewport. If slide one is 1:1 and slide two is 9:16, slide two gets letterboxed.
• Video slides cannot be mixed with image slides in the same carousel. Threads enforces all-image or all-video.
• The 1:1 aspect is by far the safest. Portrait 4:5 carousels get cut off on the right by the "next slide" hint on iOS.

Video specs and codecs

Threads accepts H.264 (baseline, main, high) and H.265 video in MP4 or MOV containers. As of March 2026 it also accepts AV1 in MP4, which is the first Meta surface to do so. AV1 uploads skip Meta's re-encode pass when they pass validation, which means your source quality is preserved instead of being run through the usual H.264 at ~3 Mbps squash.

Video parameters that matter:

• Frame rate: 23.976, 24, 25, 29.97, 30, or 60 fps. 48 and 50 are rejected.
• Max bitrate on upload: 50 Mbps. Beyond that you get a transcoding queue delay.
• Audio: AAC-LC at 128 kbps is the sweet spot. Opus is accepted but re-encoded.
• Resolution: 1080x1920 for 9:16 feed video. 4K is accepted but downscaled.

Link previews and the OG image

When you paste a URL, Threads fetches your OG image, crops it to 1.91:1, and caches it. The 2026 pipeline is stricter than the 2024 version in one way: if the OG image is smaller than 600 px on the short edge, the preview card renders with no image at all rather than upscaling. A surprising number of marketing sites still ship 600x315 OG images and wonder why their Threads previews are text-only.

Design OG images at 1200x630 minimum, and make sure the critical content is inside the center 1100x570 safe zone. Meta's crop behavior occasionally trims 50 px off each edge.

Profile media

The banner image on Threads profiles was removed in the October 2025 redesign, so profile customization is now just:

• Avatar: 1:1, minimum 320x320, rendered as circle at 128x128 in feed and 168x168 on profile.
• Bio: text only.
• Pinned posts: up to two.

If you are still maintaining an Instagram banner for brand consistency, it does nothing on Threads.

Compression and format choices

Threads re-encodes uploaded JPEGs to JPEG at quality ~85 and 4:2:0 chroma subsampling. PNG uploads with no transparency are re-encoded to JPEG. PNG uploads with transparency are preserved as PNG. WebP uploads are accepted and preserved if under 8 MB, otherwise they are re-encoded to JPEG.

For photo content, upload JPEG at quality 92. For screenshots and graphics with text, upload PNG. For illustrations where alpha matters, PNG is the only option that survives cleanly.

If you are doing weekly cross-posts and want to keep one master file that renders well on both platforms, 1440x1800 JPEG quality 92 is the single asset to generate. Resize a batch of them in the browser with Konvrt's batch tool, and export link preview images at 1200x630 through the single-image converter.

Alt text and accessibility

Threads made alt text a first-class field in 2026. You can add alt text per image on both singles and carousels. Posts without alt text do not get suppressed, but they are excluded from the "For You" algorithm's image-heavy surfaces, per Meta's March 2026 transparency report.

Takeaway: compose at 1440x1800 for the portrait post, stop reusing 1080x1350 Instagram exports on Threads, and fix your OG image if it is smaller than 1200x630.