LinkedIn ad image size: 1200×628, 1:1, and 4:5 specs

LinkedIn recommends 1200×628 pixels (1.91:1) for a single image ad, 1200×1200 for a square one and 720×900 for a vertical 4:5 one, as a JPG, PNG or GIF of up to 5 MB. For carousel ad cards it recommends 1080×1080 (1:1). On Sume, ChatGPT Image 2.5 generates 1200×1200 exactly; for the other sizes, ask for a valid custom size of the same shape and resize it.

LinkedIn's numbers are quoted from its Single image ads advertising specifications and Carousel Ads advertising specifications pages. Sume facts come from the Image API docs and the Sume API reference. All were read on 2026-09-28.

What image size do LinkedIn ads use?

LinkedIn marks 1.91:1 and 4:5 as recommended ratios. It recommends vertical images for single image ads, but paid vertical images serve only on mobile devices, and a 1:1.91 vertical image gets borders on both sides, so use 4:5.

What are the file rules for LinkedIn image ads?

• JPG, PNG or GIF; an animated GIF can have at most 250 frames.
• 5 MB at most, and 7680×4320 pixels at most. An image less than 401 pixels wide shows as a thumbnail.
• LinkedIn scales images down automatically, whatever their original size.
• Square and vertical images might be cropped when ads are shared organically. For thumbnails, LinkedIn recommends ratios between 3:2 and 16:9.

How do I make each size with Sume?

Send POST /v1/images to ChatGPT Image 2.5 (openai/gpt-image-2.5) with a custom image_size. Both edges must be multiples of 16, and the image must have at least 655,360 pixels. 1200×628 fails the first rule; 720×900 fails both, at 648,000 pixels. So ask for 3056×1600, exactly 1.91:1, or 960×1200, exactly 4:5, and resize in an image editor. Both requested sizes are inside LinkedIn's ranges too.

• Ask for jpeg and check that each file is 5 MB or less.
• The charge is estimated from the image's size and quality, and usage.cost in the response is the USD amount billed.
• Results are Sume-hosted, signed URLs in data[].url, so download the files you keep.

curl -X POST "https://api.sume.com/v1/images" \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-image-2.5",
    "prompt": "Vertical ad image for a payroll app: a small-business owner at a laptop in a bright office, calm colors, no text",
    "image_size": { "width": 960, "height": 1200 },
    "output_format": "jpeg"
  }'

What size are LinkedIn carousel ad images?

A carousel ad has 2 to 10 cards. Each card is a JPG, PNG or non-animated GIF of up to 10 MB and 4320×4320 pixels, with 1080×1080 (1:1) recommended; LinkedIn scales cards to 312×312, and you can't edit the cards once the ad is saved.

1080 isn't a multiple of 16, so ask ChatGPT Image 2.5 for 1200×1200 and resize to 1080×1080. n returns up to 4 images per call on this model today, so ten cards take three calls. You can also send an approved card in input_references as a reference for the rest: a public HTTPS URL, up to 16 per request on this model. AI Instagram carousel post generator shows the same method for Instagram.