Clearer upload
Recommended512×512 1:1
Practical square master. Survives inbox and app thumbs better than a soft 256×256 upscale.
Use in toolSubstack · Image size
Substack Logo Size
Substack logos need a square at least 256×256. Export a bold 512×512 mark (PNG with transparency when you can), then download in your browser.
Browser crop · stays on your device
Crop your Substack logo
512 × 512
Add a photo to crop
Upload a logo or mark—or try the sample—then keep one bold shape in the center before you download.
Size specs
Always square. The logo appears small in inboxes, the app, and headers—one bold mark beats thin wordmarks.
Publish
Export this for Substack upload.
| Asset | Pixels | Ratio | Notes | Action |
|---|---|---|---|---|
| Clearer upload Recommended | 512×512 | 1:1 | Practical square master. Survives inbox and app thumbs better than a soft 256×256 upscale. | Use in tool |
What Substack shows
Reference sizes and crops—not always separate upload files.
Official minimum
256×256 1:1
Substack help lists at least 256×256 with a transparent background when possible.
Use in tool| Asset | Pixels | Ratio | Notes | Action |
|---|---|---|---|---|
| Official minimum | 256×256 | 1:1 | Substack help lists at least 256×256 with a transparent background when possible. | Use in tool |
Substack logos are stamps in inboxes—not posters
Your publication logo shows beside emails, in the Substack app, and on the site header. Those surfaces shrink the file to a tiny tile. A cinematic photo with a thin subtitle fails; a high-contrast mark still parses while someone scans their inbox.
Substack help asks for at least 256×256 with a transparent background when possible. Prefer a clearer 512×512 master so compression and retina lists stay readable. Wordmarks that need 21:4 belong in the separate wordmark slot—not forced into this square.
The welcome-page cover is a different square job (at least 600×600). Social / post preview cards use a wide ~14:10 frame. Do not stretch one export into every slot.
Email banners are another strip (about 1100×220). Keep the logo as identity and the email banner as a horizontal brand bar.
Good vs weak crop
Same circle mask—corners disappear; design for the tiny comment-size icon.
Reads in an inbox row
- One bold center mark
- True square export
- Transparent PNG when useful
Thin type or wrong ratio
- Paragraph of text at logo size
- Landscape OG card squashed into 1:1
- Soft 64px upscale
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.
Publication logo
512 × 512 (try)
This page. Inbox / app / header mark.
Cover image
600 × 600 min
Welcome-page square—separate file.
Social / post preview
1456 × 1048
~14:10 share card—not a logo.
Email banner
1100 × 220
Wide email header strip.
| Surface | Typical size | Note |
|---|---|---|
| Publication logo | 512 × 512 (try) | This page. Inbox / app / header mark. |
| Cover image | 600 × 600 min | Welcome-page square—separate file. |
| Social / post preview | 1456 × 1048 | ~14:10 share card—not a logo. |
| Email banner | 1100 × 220 | Wide email header strip. |
Design for inbox and app thumbs
Treat the logo like an app icon. Fill, contrast, and a single silhouette beat a collage. If the publication name must appear on the image, use one short word in heavy type inside the center guide.
- Squint until the preview is stamp-sized.
- Avoid photo mosaics—they become gray texture.
- Transparent PNG keeps the mark clean on light and dark UI.
Logo vs cover vs social preview
The logo is identity. The cover dresses the welcome page. The social preview is the card people see when a post is shared. Export each on purpose.
- Cover size — welcome-page square
- Social preview size — 1456 × 1048 share card
- Email banner size — 1100 × 220 strip
File requirements
PNG with transparency is ideal for flat logos. JPG works for photo-based marks. Prefer sRGB. Substack may recompress—bold geometry survives better than fine serifs.
- Clearer upload
- 512 × 512 px
- Official minimum
- 256 × 256 px
- Aspect ratio
- 1:1
- Formats
- PNG (preferred) or JPG
- Background
- Transparent when possible
Common mistakes
- Using a wide wordmark meant for the wordmark slot.
- Uploading a soft 128×128 file.
- Reusing the social preview landscape as the logo.
- Putting the only title on a thin rim the tile softens.
How to use the crop tool
Upload a mark, choose Clearer upload (512×512), drag until the shape fills the center guide, then download. Processing stays in your browser.
- Prefer PNG for flat logos.
- Judge the result in an inbox preview after publish.
After you download
From this download to a live upload in a few minutes.
- 1
Download the square PNG (preferred for logos) or JPG from the tool.
- 2
In Substack, open Website / publication settings and update the logo.
- 3
Send yourself a test email or open the app and check the sender tile.
- 4
If the mark disappears at inbox size, simplify and re-crop.
Frequently asked questions
What size is a Substack logo?
At least 256×256 square. Prefer a clearer 512×512 export so inbox and app thumbs stay readable.
Should the logo have a transparent background?
Yes when you can—Substack recommends transparency for logos. Use PNG for flat marks.
Is the logo the same as the cover image?
No. The cover is a separate welcome-page square (at least 600×600). Crop each file separately.
Can I crop Substack logos here?
Yes. The in-browser crop stays on your device until you download and upload to Substack yourself.