Resize images for email headers — Newsletter Banner 600×200, Email Banner 600×300, Signature Image 300×100. Free online, no upload required.
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All recommended Email Header image dimensions for 2026. Upload at these exact sizes to avoid any quality loss from platform-side scaling.
| Type | Width × Height | Aspect Ratio | Notes |
|---|---|---|---|
| Newsletter Header | 600 × 200 px | 3:1 | Standard email header banner |
| Email Banner | 600 × 300 px | 2:1 | Wider banner for promotional emails |
| Signature Image | 300 × 100 px | 3:1 | Logo or headshot for email signature |
Open ResizePack, drop your image and select the Email Header preset — Newsletter Header, Email Banner, or Signature Image.
For email signatures, keep the image under 50 KB after resizing — use our Compress tool to optimize further. Large signature images trigger spam filters and slow email loading.
Download and insert into your email template. For Mailchimp, ConvertKit, or Brevo, upload the resized image to their media library. For Gmail signatures, paste or insert the image in Settings > Signature.
Ready to resize?
Use Batch Resize for batch resizing with social media presets, or Crop & Ratio to crop to the exact aspect ratio first.
600 px wide is the email standard because most email clients render at 600 px max width. Height varies — 200 px for compact headers, 300 px for promotional banners. Some modern templates use 640 or 700 px widths, but 600 px guarantees compatibility.
300×100 px is the practical maximum for email signature logos. Larger images push content below the fold and can trigger spam filters. Keep file size under 30-50 KB — use JPEG for photos or PNG for logos with transparency.
No — many email clients (Outlook, older Gmail) do not support WebP. Always use JPEG for photographic email images and PNG for logos or graphics. This ensures your images render correctly across Gmail, Outlook, Apple Mail, and all other clients.
Outlook on Windows renders images at 96 DPI regardless of the image resolution. To compensate, export at 2x size (1200×400 px) and set the HTML width to 600 px. SammaPix can resize to either standard or retina dimensions.
Keep individual email images under 200 KB, and total email size under 100 KB of HTML plus 500 KB of images. Gmail clips emails over 102 KB of HTML. Use SammaPix Compress after resizing to hit optimal file sizes.
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Resize multiple images at once with the same settings. Download all as ZIP in seconds.
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Need dimensions for every platform in one place? Read our complete 2026 cheat sheet- every network, every format, updated for this year.
Social Media Image Sizes 2026