Skip to content

Image sizes and formats by platform

A reference for the image shape each platform and post format expects.

BWritten by the Brandmundo teamUpdated June 6, 2026

Every platform has its own native shape, and Brandmundo generates and previews media in the right one automatically — you never crop by hand. This is the full reference of formats and their aspect ratios.

Formats and aspect ratios

PlatformFormatAspect ratioMedia
InstagramSingle / Carousel1:1 squareImage
InstagramReel / Story9:16 portraitImage or video
LinkedInPost / Document4:5 tallImage
LinkedInVideo16:9 widescreenVideo
LinkedInPollText only
XImage16:10 widescreenImage
XText / ThreadText only
FacebookPost3:2 widescreenImage
FacebookVideo16:9 widescreenVideo
FacebookReel9:16 portraitImage or video
TikTokVideo9:16 portraitVideo

What this means in practice

  • AI image generation renders in the format's native ratio — an Instagram single comes out square, a story comes out 9:16.
  • Post previews in the deck and composer frame your media exactly as the platform will, so what you approve is what your audience sees.
  • Text-only formats (X posts and threads, LinkedIn polls) simply have no media slot — the words are the post.

Hashtag conventions per platform

Generated captions also follow each platform's hashtag culture: around 5–8 on Instagram, 3–5 on LinkedIn and TikTok, 2–3 on Facebook, and a sparse 1–2 on X. You can always edit the set before publishing.

These shapes follow each platform's own specifications. For the latest exact figures, see the official help centres for Instagram, Facebook, LinkedIn and TikTok.

Related articles

Can't find what you're looking for? Send us a message — we'll reply as soon as possible, usually within 8 hours.