X image sizes and editors
Header images that survive the avatar overlap, and post images cropped to the ratio the timeline keeps.
The rename from Twitter to X changed the branding, not the dimensions. The header is still 1500 × 500 with a 2 MB ceiling, and post images still get centre-cropped in the timeline unless you give them a ratio the card keeps.
Because “twitter banner size”, “twitter header size” and “x banner size” all describe one asset, they get one page here rather than three near-identical ones. The same applies to post images.
Runs on your device. Your image is decoded, cropped and encoded by this browser tab. It is never uploaded, and there is no image-processing service behind this page.
Profile
The header, with the avatar overlap and mobile crop marked.
Posts
Timeline image ratios that do not get cropped.
X questions
Did the X header size change from Twitter?
No. 1500 × 500 at 3:1, under 2 MB, in JPEG, PNG or GIF. Only the name changed.
Why does X crop my post images?
The timeline card renders a centre crop of anything whose ratio it does not keep. Exporting at 16:9 or 1:1 avoids it.
Doing more than one platform?
The One Image to Social Pack applies a single focal point across every destination you pick and gives you one ZIP with a manifest listing each size, its source and the date it was checked.