X (Twitter) Header Size Resizer

X (formerly Twitter) recommends a header image of 1500 × 500 pixels, a wide 3:1 strip across the top of your profile. Most photos are 4:3 or 16:9, so uploading them directly means X crops them for you, often cutting off heads or text. This resizer crops or fits your image to exactly 1500 × 500 px, lets you choose which part is kept, and draws a guide preview showing where your round profile photo sits over the bottom-left corner.

How to use this tool

1. Choose your image (or several to process in one go).
2. Keep the header size, or switch to the 400 × 400 profile photo.
3. Pick "Crop to fill" and move the vertical position to keep the part you want, or show the whole image on a colour or blurred background.
4. Check the guide preview: keep text away from the red areas.
5. Download the JPG and upload it in Edit profile on X.

Formula

scale = max(1500 ÷ width, 500 ÷ height) × zoom · kept area = 1500 ÷ scale by 500 ÷ scale, centred on the chosen position

With "show the whole image" the scale is the minimum of the two ratios instead, and the empty space is filled with your colour or a blurred, enlarged copy of the photo. The guide marks the profile photo (about 22% of the header width, centred on the bottom edge near the left) and the top and bottom 12% that some screens trim.

Example

A 4000 × 3000 phone photo has scale = max(1500/4000, 500/3000) = 0.375. The kept area is 4000 × 1333 px, so the header shows the full width and the middle 44% of the height. Moving the vertical position to −100% keeps the top 1333 rows instead, which suits a skyline with sky above.

Header sizes on X

X's help centre lists 1500 × 500 px for headers and 400 × 400 px for profile photos. The header is shown wider than it is tall on every device, but the visible strip and the avatar position change between the website and the apps, so the guide is approximate. Keep logos and text in the centre band and away from the bottom-left corner.