What size should images be in an email newsletter?
The template sets the width. Most newsletters are 600–700 px wide (Mailchimp's current builder uses 660 px, its legacy templates 600 px), and phones and laptops with high-density screens show them at 2×. So export full-width images at 1200–1400 px wide and let the template display them at half size. Keep images under about 2000 px tall, as Klaviyo recommends, so they do not turn into a long scroll on phones.
Guidelines for a 600–700 px template. Photos as JPEG at quality 70–80; logos as PNG.
| Image | Displayed width | Export width | Target weight |
|---|---|---|---|
| Full-width hero | 600–700 px | 1200–1400 px | 100–200 KB |
| Two-column image | 300–330 px | 600–660 px | 40–80 KB |
| Three-column product tile | 200–220 px | 400–440 px | 20–50 KB |
| Logo | 150–200 px | 300–400 px | Under 20 KB |
| Animated GIF | Up to 600 px | Same as displayed (1×) | Under 1 MB |
What are the image limits in Mailchimp, Klaviyo and Brevo?
As of October 2026, from each platform's help center.
| Platform | Upload limit per image | Its own recommendation | Formats |
|---|---|---|---|
| Mailchimp | 1 MB in the content studio | 660–1320 px wide in the new builder, 600–1200 px in legacy templates | JPG, PNG, GIF (BMP also accepted) |
| Klaviyo | 10 MB | 1 MB or smaller; 600–1000 px wide, under 2000 px tall | JPEG, PNG, GIF; WebP can be converted to PNG on upload |
| Brevo | 5 MB in the content library | GIFs from its GIF library are capped at 2 MB | PNG, JPEG, GIF |
Klaviyo also compresses images on upload. Even so, starting from a resized, compressed JPEG gives you control over how the image looks instead of leaving it to each platform.
How do I compress images for a newsletter?
- Crop each image to its slot and export it at 2× the template width: 1200 px for a 600 px template, 1320 px for Mailchimp's 660 px layout.
- Open Compress JPG and drop the images. They are processed in your browser, not uploaded.
- Turn on Limit width at 1200–1400 px if your exports are larger.
- Choose Target size and type 200 KB for a hero image, or 100 KB for smaller images, and the tool finds the highest quality that fits.
- Upload the JPEGs to your email platform and add alt text, since many readers see the email before images load.
Can I use WebP images in emails?
Not safely yet. In Can I Email's tests, classic Outlook for Windows (versions 2007 through 2019) does not display WebP, and Gmail converts WebP to JPEG. Mailchimp and Brevo do not list WebP among their upload formats, and Klaviyo offers to convert it to PNG. Use JPEG for photos and PNG for logos, flat graphics and anything with transparency; keep WebP for the landing page the email links to, as explained in convert email images to WebP.
How heavy should a whole newsletter be?
There is no single hard limit for images, but every reader downloads all of them, often on mobile data, and they are fetched from your platform's servers at the moment the email is opened, so heavy files slow down the first impression. A practical budget is under about 1 MB of images per email, with the hero at most 200 KB. The HTML is a separate budget: Gmail clips messages whose HTML exceeds 102 KB and hides the rest behind a “View entire message” link. Hosted images do not count toward those 102 KB, but images embedded as base64 inside the HTML do, so never embed them.
What about animated GIFs in email?
GIFs are limited to 256 colors per frame and grow quickly with every frame and pixel, so keep them at 1× (600 px or less), with few frames, and under about 1 MB. Outlook 2007–2016 for Windows shows only the first frame, so put the key message there. Use a dedicated GIF editor to trim frames and colors: Fast WebP Converter keeps only the first frame of an animated GIF, so it is not the right tool for animations.