Short answer
Your X 'background' is two things: the app theme (Settings > Accessibility, display and languages > Display, where you choose Light, Dim or Lights out plus color and font size) and your profile header image (Edit profile > header, 1500 x 500 pixels).
Key takeaways
- Themes change only what you see; your header image is what everyone sees.
- The header should be 1500 x 500 pixels and is cropped differently on phones and desktops.
- Custom profile background colors and patterns from the old Twitter era no longer exist.
On old Twitter you could paint your profile page with a tiled background. That ended years ago. Today "changing your background" on X means one of two things, and they're in different places.
How do I change the theme?
Settings and privacy > Accessibility, display and languages > Display.
There you'll find:
- Background: Default (white), Dim (dark blue) or Lights out (black).
- Color: the accent used for buttons and links, from a handful of options.
- Font size: a slider that scales text across the app.
In the app, the same settings live under Settings and privacy > Accessibility, display and languages > Display and sound, with a dark mode option that can follow your phone's system theme. These choices affect only what you see. Your followers see X in their own theme.
How do I change my header image?
Go to your profile, choose Edit profile, and tap the header area to upload a new image.
Use 1500 × 500 pixels (3:1), JPG or PNG. X compresses headers, so start sharp. The profile photo overlaps the lower-left part of the header, and phones crop the top and bottom slightly, so keep text and faces in the middle.
What makes a good header?
Something that reinforces who you are without competing with your photo.
- A product shot, a workspace, a city skyline, or a simple pattern in your brand colors.
- A short line of text in the center, if any: a tagline, a launch date, your newsletter.
- Avoid busy photos behind the profile picture corner.
Test the combination in our profile header mockup, which uses x.com's layout and crop.
Can I get the old Twitter look back?
Not officially; the closest you get is the theme settings and a classic-style mockup.
Browser extensions that restyle X exist, but they read the page you're viewing; install only well-reviewed ones with minimal permissions. More options in can you get the old Twitter back?
Questions people ask
Can I set a custom background image like old Twitter?
No. Twitter removed custom profile backgrounds in its 2014-2017 redesigns. Today you control the header image, your photo and the app theme for your own view.
Why does my header look cropped?
X shows the header at different shapes on mobile and desktop, and your profile photo covers the bottom-left corner. Keep important content in the center band.
How do I turn on dark mode?
Settings and privacy > Accessibility, display and languages > Display > Background, then choose Dim or Lights out. In the app you can also follow your phone's system setting.