What size should an X/Twitter video thumbnail be?

Use 1280x720 pixels at a 16:9 ratio, under 5 MB, in JPG or PNG. Custom thumbnails are available to verified and Premium accounts; otherwise X picks a frame from the video. Keep titles and faces in the centre of the frame.

What is the best image ratio for an X post?

A 16:9 image at 1600x900 is the cleanest in-timeline ratio because X shows it without cropping. Square 1200x1200 and portrait images expand fully on tap but are centre-cropped toward 16:9 in the timeline.

What size is the X summary card image?

The large summary card image (twitter:card set to summary_large_image) renders at about 1.91:1, so use 1200x628 under 5 MB. The compact summary card uses a square image of at least 144x144, with 240x240 recommended.

Why does X crop my image in the timeline?

X crops non-16:9 media toward a landscape preview to keep the feed compact. The full image appears when a user taps it, but the timeline thumbnail is cropped, so keep important content within the central, uncropped region.

What file types and sizes does X accept?

X accepts JPG and PNG up to 5 MB and GIF up to 15 MB for in-post media. Use PNG for crisp text and logos and high-quality JPG for photos to balance sharpness against the size cap.

X/Twitter Thumbnail Size Tool

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X resizes and crops preview images differently for video posters, in-post media, and link cards, so a thumbnail that looks perfect in your editor can end up truncated in the feed. This tool gives you the exact dimensions, ratio, and cropping behaviour for each X surface.

How it works

Pick a content type and the tool returns the native specification X uses:

Video thumbnail / poster: 1280x720 (16:9), shown without crop, under 5 MB.
Single in-post image: 1600x900 (16:9) for the cleanest timeline render.
Square in-post image: 1200x1200 (1:1), expands on tap but is cropped toward 16:9 in the feed.
Summary card (large): 1200x628 (1.91:1), set via the twitter:image meta tag.
Summary card (square): 240x240 (1:1), minimum 144x144, for the compact card.

Each result lists the recommended size, aspect ratio, timeline-crop behaviour, format, and file-size cap, with a quick at-a-glance table of every surface.

Tips and example

Design link previews to the summary card spec by setting twitter:card and twitter:image in your page head — a 1200x628 image fills the large card cleanly. For in-post photos, prefer 16:9 so the timeline shows them uncropped; if you must post a square or portrait image, keep faces and text in the central band that survives the 16:9 crop. Export logos and text overlays as PNG for sharp edges and photos as high-quality JPG to stay under the 5 MB cap.