Compress image for Substack Newsletter
Substack emails render images at 1400 px max. Uploads should target that dimension and JPEG format.
Your images stay on your device. Nothing is uploaded.
Substack newsletters are delivered by email. Email clients (particularly Outlook desktop) don't render WebP, so JPEG is the safe format. Substack accepts up to ~ 25 MB per image but chokes on very large uploads.
This preset produces a 1400 px JPEG at quality 85 — sharp on retina, ~ 350 KB per image.
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Frequently asked questions
- What size should an image be for Substack newsletter body image?
- The preset on this page reflects the recommended dimensions for Substack newsletter body image. Uploading at these dimensions avoids the auto-crop or auto-downscale that the platform would otherwise apply.
- Does the platform re-encode after upload?
- Yes — most platforms re-encode uploaded images to their internal format and bitrate. Starting from a clean, correctly sized image means only one round of lossy re-encoding rather than two.
- What format should I use for Substack newsletter body image?
- The preset uses the format recommended for Substack newsletter body image. JPEG is the safest universal choice; some workflows benefit from WebP or PNG for specific reasons (transparency, screenshots, etc.).
- Is anything uploaded?
- No. The compression and resize run in your browser. The image only leaves your device when you upload it to Substack newsletter body image yourself.
- Can I batch process multiple images for Substack newsletter body image?
- Yes — use the bulk compressor to process a folder of images with the same settings. Every image gets the correct dimensions and quality for Substack newsletter body image.
Prepare a Substack — newsletter body image image.
Drop your image — the tool applies the correct dimensions and quality for the platform.
Start compressing