Image sizes for social media: the guide that doesn't change every month

Each social network decided independently, and at different moments, which image proportion it prefers — and those decisions are neither arbitrary nor capricious: they reflect how we hold our phones, how much space the app's own interface takes up, and which content format the platform wants to prioritise. The result is that there is no universal "one size" — there's a catalogue worth knowing, not memorising.

The dimensions actually used today

Instagram still works primarily in three formats: the square post (1080×1080), the vertical 4:5 (1080×1350) which takes up more space in the mobile feed, and the full-screen story (1080×1920). TikTok went further and made the vertical 9:16 the default standard — not just one option among many. YouTube keeps the classic 16:9 (1280×720) for thumbnails, but also requires vertical 1080×1920 for Shorts — two formats coexisting on the same platform. LinkedIn and Facebook, still more desktop-oriented, use wider proportions for banners (1584×396 and 820×312 respectively) that would not work at all in a story.

Why size matters more than resolution

It's tempting to think that uploading the largest, sharpest image possible is always the safe choice. It isn't: if the file doesn't match the proportion the platform expects, it will be cropped automatically — almost never in the way you would choose. A face centred in the original can end up cut in half. A logo in a corner can disappear entirely. High resolution doesn't prevent that problem — only the correct framing does.

The safe zone almost no one accounts for

In stories and reels, beyond getting the size right, there's an extra layer: the app's own interface covers a strip at the top and bottom with the clock, icons, progress bar or reply text. Designing right up to the edges is the most common way for a text or logo to end up hidden from many viewers on their phone — even if it looks perfect in the desktop editor.