Recommended image dimensions

1200 x 630 pixels (1.91:1 ratio). LINE is predominantly mobile, so images display within phone-screen constraints in a compact card above the title and description.

Display behavior

Rounded cards with image at top, title and description below. Images scale to fill card width and may be center-cropped. Keep important content centered.

Supported formats

JPEG and PNG. WebP support varies by LINE client version – JPEG for photos, PNG for graphics with text or transparency is the safe choice.

Size considerations

Despite the 20MB page download limit, keep images reasonable:

• Under 1MB for fast mobile loading
• Under 200px in either dimension may not display
• Very large images may timeout on slower connections

Image URL requirements

The og:image URL must be:

• An absolute URL (not relative)
• Accessible without authentication
• Served over HTTPS
• Not behind JavaScript-based redirects

When no image is provided

LINE shows a text-only preview with title and description. Functional, but less engaging in the chat stream.