Clearer upload
Recommended1200×1200 1:1
Practical square master above the 600×600 floor for sharper welcome-page art.
Use in toolSubstack · Image size
Substack Cover Size
Substack cover images need a square at least 600×600 for the welcome page. Export a clear 1200×1200 when you can, then download in your browser.
Browser crop · stays on your device
Crop your Substack cover
1200 × 1200
Add a photo to crop
Upload a photo or brand still—or try the sample—then keep the subject in the center before you download.
Size specs
This is the welcome-page cover square—not the wide social / post preview card and not the tiny logo stamp.
Publish
Export this for Substack upload.
| Asset | Pixels | Ratio | Notes | Action |
|---|---|---|---|---|
| Clearer upload Recommended | 1200×1200 | 1:1 | Practical square master above the 600×600 floor for sharper welcome-page art. | Use in tool |
What Substack shows
Reference sizes and crops—not always separate upload files.
Official minimum
600×600 1:1
Substack help lists at least 600×600 for the publication cover image.
Use in tool| Asset | Pixels | Ratio | Notes | Action |
|---|---|---|---|---|
| Official minimum | 600×600 | 1:1 | Substack help lists at least 600×600 for the publication cover image. | Use in tool |
Substack covers are welcome-page squares
The cover image sits on the publication welcome page above your name and subscribe button. Substack help asks for at least 600×600. Prefer a clearer 1200×1200 so the art stays intentional after compression.
If you leave the cover empty, Substack often falls back to the logo. That can look unfinished next to competitors with a dedicated square. Crop a real cover when branding matters.
Social / post preview images are a different ratio (~14:10, often 1456×1048). Stretching the welcome square into that share card crops faces badly. Export two files.
The logo remains the small identity mark for inboxes. Do not replace the logo with this larger cover crop—or the reverse.
Good vs weak crop
Same feed frame—keep the subject inside the margin phones actually show.
Strong welcome square
- True square export
- Subject centered
- Clearer than the 600 floor
Wrong share-card crop
- Landscape OG card squashed to 1:1
- Soft 600 upscale with noisy detail
- Logo wordmark stretched as a “cover”
Before you upload
Tick these off against your crop preview—nothing is saved.
Related surfaces compared
Similar-looking slots often use different ratios—do not reuse one export for all of them.
Cover image
1200 × 1200 (try)
This page. Welcome-page square.
Logo
512 × 512
Inbox / header mark—smaller job.
Social / post preview
1456 × 1048
Wide share card—different ratio.
| Surface | Typical size | Note |
|---|---|---|
| Cover image | 1200 × 1200 (try) | This page. Welcome-page square. |
| Logo | 512 × 512 | Inbox / header mark—smaller job. |
| Social / post preview | 1456 × 1048 | Wide share card—different ratio. |
Treat the welcome page like a book cover
Readers decide in a glance. A calm photo or bold brand field beats a busy collage. Keep the subscribe CTA readable—do not bury the only hook under dense type on the image.
- One subject, high contrast.
- Leave breathing room around faces.
- Match tone with the logo without cloning the same file.
Cover is not the social preview
Share cards use a wider ~14:10 frame. Reusing this square for Open Graph-style previews usually clips the sides or adds padding. Crop the social preview page separately.
- Social preview size — 1456 × 1048
- Logo size — 512 × 512 stamp
File requirements
JPG for photos, PNG for flat graphics. Prefer sRGB. A clean 1200×1200 usually looks sharper than a noisy minimum upload.
- Clearer upload
- 1200 × 1200 px
- Official minimum
- 600 × 600 px
- Aspect ratio
- 1:1
- Formats
- JPG, PNG, or WebP (sRGB stills)
Common mistakes
- Using the social preview landscape as the welcome cover.
- Leaving the cover empty and hoping the logo is enough.
- Uploading a soft 600×600 with fine type.
- Putting the only headline on the extreme edge.
How to use the crop tool
Upload a photo, choose Clearer upload (1200×1200), drag until the subject sits in the center, then download. Cropping stays in the browser.
- Prefer JPG for photographs.
- Check the live welcome page after publish.
After you download
From this download to a live upload in a few minutes.
- 1
Download the square JPG or PNG from the tool.
- 2
In Substack website settings / Basics, update the cover image.
- 3
Open the public welcome page on phone and desktop.
- 4
If faces feel cropped, re-crop here and replace the file.
Frequently asked questions
What size is a Substack cover image?
At least 600×600 square. Prefer 1200×1200 for a clearer welcome-page upload.
Is the cover the same as the social preview?
No. Covers are square. Social / post previews use a wider ~14:10 frame (often 1456×1048).
What if I skip the cover?
Substack may fall back to your logo. A dedicated cover usually looks more intentional on the welcome page.
Can I crop Substack covers here?
Yes. The in-browser crop stays on your device until you download and upload to Substack yourself.