Substack Social Preview Image Resizer

Prepare a 1200×630 Substack social or post preview and keep the subject centered for thumbnail cropping.

Sizes, to scale

  • Social Preview Image

    1200×630

    1.9:1

  • Welcome Page Cover

    600×600

    1:1

  • Wordmark

    1344×256

    21:4

+2 more sizes below

Substack social preview size

Substack social preview size: At least 1200×630 px

Substack also describes a 14:10 preview crop, so treat 1200×630 as the source canvas and inspect the generated preview.

1200

width (px)

630

height (px)

~17:9

aspect ratio

Need other dimensions? Browse all Substack sizes or use the free image resizer for any platform.

Sources

We check platform-specific dimensions against source documentation when available.

Prepare Substack Social Preview Image

Place the subject and short headline near the center so the image can tolerate a tighter thumbnail crop. The official help text mentions both a 1200×630 minimum and a 14:10 preview ratio, so the live preview is the final authority.

How to resize an image for Substack Social Preview Image?

  1. 1

    Step 1: Choose a suitable source image

    Choose a landscape image with generous space around the focal subject.

  2. 2

    Step 2: Apply the 1200×630 preset

    Upload the image, choose Social Preview, and use Fit or Fill to control the crop.

  3. 3

    Step 3: Review and upload

    Download the image, add it as the post preview, and inspect the generated card before sharing the link.

FAQ

Substack Social Preview Image FAQ

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What size should a Substack social preview image be?

Substack recommends at least 1200×630 pixels and notes that preview thumbnails can use a 14:10 crop.

Will the 1200×630 preset prevent every crop?

The official help text mentions both a 1200×630 minimum and a 14:10 preview ratio, so the live preview is the final authority. Keep the source file so you can revise the crop if the destination changes its layout or requirements.