Social Media Specs
Threads Specs
Threads is the newest surface in this reference and the one changing fastest, so I have kept it to the values that have held stable and flagged the rest. The short version is that it accepts Instagram sized assets, rewards conversation over links, and punishes the copy and paste cross post more than any other platform I work on.
| Field | Limit | Notes |
|---|---|---|
| Post text | 500 characters | Chain posts to continue past the limit |
| Media per post | Up to 10 images or videos | Shown as a swipeable carousel |
| Bio | 150 characters | Mirrors the Instagram bio length |
| Links in post | Supported | One link renders a preview card |
| Media | Aspect ratio | Recommended pixels | Notes |
|---|---|---|---|
| Image, portrait | 4:5 | 1080 x 1350 | Best use of feed height |
| Image, square | 1:1 | 1080 x 1080 | Safe default |
| Image, landscape | 1.91:1 | 1080 x 566 | Smallest footprint |
| Video | 9:16 or 1:1 | 1080 x 1920 | Short form performs best |
| Profile photo | 1:1 | 320 x 320 | Displayed as a circle |
Notes
Threads rewards replies far more than any other Meta surface. A post that generates a thread of responses keeps resurfacing, and replying to your own post to add context is normal behaviour rather than a growth hack. Budget time to sit in the replies for an hour after posting, or do not post.
The account is tied to Instagram, which means your Threads follower graph is seeded from an audience that opted in to a different content format. What worked as an Instagram caption usually reads as marketing on Threads. Rewrite rather than syndicate.
Link posts are visibly deprioritised relative to text and image posts, which is consistent with how Meta treats outbound links elsewhere. If a link is the point, put the argument in the post and the link in a reply, then check whether reach actually improves for your account rather than trusting the general claim.
Threads is still adding and moving features, and character limits and media handling have changed since launch. Verify against the official Threads help documentation before you commit a template or a scheduling tool to an exact spec.
Frequently asked questions
Should I cross post Threads content from Instagram?
Only the media, never the caption. Threads reads as conversational and short, and an Instagram caption pasted across lands as an ad. The extra ten minutes of rewriting is the whole difference in performance.
How long can a Threads post be?
500 characters per post. Chaining posts is normal and supported, so a longer argument works fine as a short sequence rather than one block.
Official sources
Platforms change specifications without notice. Check the primary documentation before a launch that depends on an exact value.
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More Social Media Specs
Social Media Image Sizes
Current image dimensions and aspect ratios for Instagram, Facebook, LinkedIn, X, TikTok, YouTube and Pinterest, in one scannable table.
Social Media Character Limits
Character limits for posts, bios, captions and headlines across Instagram, LinkedIn, X, TikTok, Facebook and YouTube.
Instagram Specs
Instagram image sizes, Reels and Stories video specs, caption and bio limits, and file requirements in one reference.
LinkedIn Specs
LinkedIn image dimensions, video specs, character limits for posts, headlines and articles, plus document post requirements.
TikTok Specs
TikTok video dimensions, aspect ratio, length limits, caption and bio character counts, and safe zone guidance for creators.
YouTube Specs
YouTube video resolutions, thumbnail and banner sizes, title and description limits, and Shorts requirements in one table.