X Post Image Size
X does not show a post image at the shape you uploaded. In the timeline the preview is capped at a 2:1 rectangle and anything taller is trimmed before it is expanded. A 1600 × 900 image at 16:9 loses the least of the accepted shapes.
X Post image size calculator
Pre-filled with 1600 × 900, the size X expects for a post image.
- Fraction
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- Closest common ratio
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- Reduced by
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Custom Ratio — pick a preset or type your own
- New size
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- Total pixels
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- CSS
aspect-ratio: —;
The 16:9 ratio is locked in. Edit New Width and the post image height recalculates instantly; edit the height and the width follows. Sizes round to whole pixels, because platforms do not accept fractional ones.
Recently used sizes
Saved in this browser only. Click a size to load it back into the calculator.
Why 16:9 loses the least in the timeline
Two units wide for every one unit tall is the cap the timeline applies. On a 1600-wide preview that works out at 800 pixels of height, so a 1600 × 900 image — 16:9, or about 1.78:1 — has a thin band removed from top and bottom. It is cropped, but only just. A square is twice as tall as the cap allows and a 4:5 portrait is taller still, so both lose far more to the same preview.
The crop applies to the timeline preview rather than to the file. Tapping the image opens it at its full shape, which is why the same post can look different to somebody scrolling past and somebody who stopped. Text and logos near the top or bottom edge are the elements that pay for this, since they are the ones sitting in the band that gets trimmed.
Every X image placement and its pixel size
The three post rows are the ones people confuse. They are all accepted, but only the landscape shape survives the timeline without meaningful cropping.
| Placement | Pixels | Ratio | Notes |
|---|---|---|---|
| Post image, landscape | 1600 × 900 | 16:9 | Recommended; loses only a thin band in the timeline |
| Post image, square | 1200 × 1200 | 1:1 | Safe everywhere, but cropped to 2:1 before expansion |
| Post image, portrait | 1080 × 1350 | 4:5 | Tallest allowed; the most crop in the timeline |
| Profile photo | 400 × 400 | 1:1 | Displayed as a circle in every context |
| Header image | 1500 × 500 | 3:1 | Cropped on mobile; profile photo overlaps the bottom left |
| Link card image | 1200 × 628 | 1.91:1 | Pulled from the page's og:image tag when a link unfurls |
How to size a post image
The ratio sets the shape and the timeline sets how much of it survives. Both are simple multiplications once the width is fixed.
- Start from 1600 px of width, the size X recommends for a single image.
- Divide by 16 to reach the unit: 1600 ÷ 16 = 100 px.
- Multiply by 9 for the height: 100 × 9 = 900 px.
- Keep any text at least a tenth of the height away from the top and bottom edges, since the timeline removes a thin band from each.
- Export as PNG for graphics with type and JPEG for photographs, then check the file against the 5 MB mobile ceiling.
Worked example
A chart exported at 3000 × 1688 is a 16:9 image with a lot of redundant pixels, and at that size a detailed chart often crosses the mobile file cap. Rescaling to 1600 × 900 keeps the shape exactly — 3000 ÷ 1.875 = 1600 and 1688 ÷ 1.875 ≈ 900 — while cutting the file weight by around two thirds. The line weights stay legible because X renders the timeline at a width the smaller file already covers.
What happens with two, three or four images
A single attached image is shown at the timeline crop described above. Attach more than one and X abandons that entirely and builds a grid instead, and the grid crops according to its own rules rather than yours.
Two images go side by side, each cropped towards a tall rectangle. Three place one large image on the left with two stacked on the right. Four produce a two-by-two square. In every case the individual image is cropped to fit the cell, and the cell shape is not the shape you uploaded.
- For a multi-image post, square images survive the grid most predictably, because a square crops to a tall cell and a wide cell at the same cost.
- Keep the subject near the centre of each image, since the grid cells crop towards the middle from whichever edge is longer.
- If a specific crop matters, post the images one at a time. The single-image layout is the only one whose crop you can predict.
- Number the images in the artwork rather than relying on order, because the grid layout changes how the sequence reads.
X post image limits
The formats matter for legibility. Screenshots and text-heavy graphics recompress badly as JPEG, which is what most of the artefacts around small type come from.
| Item | Value |
|---|---|
| Recommended size | 1600 × 900 px (16:9) |
| Lighter alternative | 1200 × 675 px, the same 16:9 shape |
| Maximum stored resolution | 4096 × 4096 px |
| Max file size, mobile | About 5 MB per image |
| Max file size, desktop | About 15 MB per image |
| Images per post | Up to four |
| Formats | JPG, PNG, GIF, WebP |
X Post image size FAQ
What size should an X post image be?
1600 × 900 pixels at 16:9 is the recommended size for a single image, and it is the shape that loses the least to the timeline's 2:1 preview crop. A 1200 × 675 version of the same ratio is lighter and still fills the preview.
Why is my tall image cut off in the timeline?
Because X caps the inline preview at a 2:1 ratio. A portrait or square image is taller than that, so the timeline crops it before expansion, and the crop point is chosen by the platform's own subject detection rather than by you.
Do I need a separate image for link previews?
Yes. A post that contains a URL unfurls a card, and the card image comes from the page's own og:image tag rather than from anything attached to the post. That image should be 1.91:1 — 1200 × 628 — not 16:9.
Is PNG or JPEG better on X?
PNG for screenshots, charts and anything with text or hard edges, because it survives the platform's recompression without blocking around the type. JPEG for photographs, where it is smaller and the artefacts are invisible.