What this tool does
The export size is the least important number in this whole subject. Every platform re-crops on upload, usually from the centre, and every one of them draws an interface on top, so the question that decides whether an image works is which part of it survives. This tool holds sixteen placements with their safe zones, draws the surviving rectangle over your own picture, and tells you which of them your current image cannot serve at all.
How it works
The platforms scale your source to cover the target frame, exactly as CSS object-fit: cover does, which means the scaled image is at least as large as the frame on both axes and one axis overflows. The safe zone is published as an inset from each edge, as a fraction of the finished frame; dividing that fraction by the cover scale maps it back into your own pixels. What you get is a rectangle in your source image that survives the crop, and the text and the logo have to live inside it.
How much that costs varies enormously, and the worst case is YouTube channel art. A 2560 × 1440 banner is shown as a band far shorter than that, and each channel row keeps only the middle 1546 × 423 of it. That is a fifth of the canvas, so a logo placed in the corner is genuinely never seen. A LinkedIn personal banner is nearly as bad: the profile photo sits over the bottom-left corner, which takes the left 30% and the bottom 25% out of play, and the same image on a phone is cropped again.
The folklore figures are all still everywhere, and two of them are wrong in ways that cost you quality. YouTube thumbnails are not capped at 2MB: the help page now recommends 3840 × 2160 with a 50MB ceiling on desktop, and the old 1280 × 720 at 2MB advice is what pushes people into heavily compressed, soft thumbnails. And 1200 × 630 is not a social media size at all, it is the Open Graph link-preview size, which predates every platform's own recommendation and is still the one number that covers every consumer of the meta tags.
The file-size ceilings are only listed where a platform documents one, which is why most rows have none. An invented limit is worse than a missing one, so where a number could not be pinned to a source it is left off, and every row carries the source it came from and the date it was read. A ceiling that has quietly changed since then is precisely the kind of error that gets a listing rejected for no visible reason.
Worked example
A 1080 × 1920 vertical design is going out as an Instagram Story and a YouTube Shorts cover.
- The Story preset insets 13% off the top and 20% off the bottom for the reply bar and share row
- On a 1080 × 1920 source that is 250px and 384px, leaving a 950 × 1286 safe rectangle at 65, 250
- The 6% side insets cover the action rail, taking 65px off each edge
- The same frame as a Shorts needs 15% off the right and 22% off the bottom, which is a different rectangle
The same export can serve both, but only if the text sits inside the tighter of the two rectangles. Outside it, the caption and the channel row cover it on one platform and the progress bar covers it on the other.
Accuracy and limitations
- Interface insets are measured from the app, not published, so treat them as generous rather than exact. The frames change with A/B tests.
- Several rules are guidance rather than hard limits, and guidance will not stop an upload. Only a documented ceiling will.
- Every placement re-crops from the centre. A subject off-centre will move in a way the size check cannot warn you about.
Frequently asked questions
- What is the right size for a social media image?
- It depends on the placement, and there are sixteen of them here. A 1.91:1 link preview wants 1200 × 630, a Story is 1080 × 1920, a YouTube thumbnail is 16:9 and a Pinterest pin is 2:3. The size is the easy half; the safe zone decides whether the image survives.
- What is the safe zone on a social media image?
- The part of the frame the platform's own crop and interface do not cover. On a 1080 × 1920 Story that is roughly 950 × 1286 pixels, inset 13% from the top and 20% from the bottom for the account row, reply bar and share rail, and 6% from each side for the action rail.
- Why is 1200 × 630 everywhere when no platform recommends it?
- Because it is the Open Graph link-preview size, and the Open Graph protocol predates every one of these platforms' own recommendations. It is still the right number for anything that is shared as a link, because one file at that size is understood by every consumer of the meta tags.
- What is the correct YouTube thumbnail size?
- The frame is still 16:9, but the current recommendation is 3840 × 2160 with a 50MB ceiling on desktop and 2MB on mobile. The old 1280 × 720 at 2MB figure repeated everywhere is out of date, and it is what pushes people into heavily compressed, soft thumbnails.
- Why is my LinkedIn banner cut off?
- A 1584 × 396 banner is 4:1, far wider than anything that displays it, so it is always cropped, and the profile photo is drawn over the bottom-left corner. That removes the left 30% and the bottom 25% of the frame, so the logo has to go in the right two-thirds, vertically centred.
- Can I upload the same image to every platform?
- The tool answers that for your specific image: it checks it against all sixteen placements and lists the ones it cannot serve, because a source smaller than a target frame is upscaled and goes soft. Within one export, keeping text inside the tightest safe zone is what makes one file work everywhere.