Compress BMP Images for Mailchimp
Mailchimp email campaigns require properly sized, email-safe images. Optimized images improve email deliverability, load faster in all email clients, and increase engagement rates. Uncompressed Windows bitmap format with very large file sizes. Not suitable for web use without compression. Use ImageSmith to compress your BMP images to the ideal file size for Mailchimp — target under 10,240KB for optimal performance. Processing is fully browser-based — no server uploads, no privacy risk.
Recommended format
JPEG
Max file size
10,240KB
Dimensions
600px wide for email body, 1200×600 for header banners
✓Email content area is 600px wide — design at 600px or 1200px (2× Retina)
✓Keep individual images under 200KB for fast email loading
✓Avoid WebP — Outlook does not support it in emails
✓Test emails across clients (Gmail, Outlook, Apple Mail) before sending