Email Header Image Resizer — Newsletter & Banner Sizes
Resize images to the exact email header dimensions. Standard 600×200, email banner 600×300, hero image 600×400. Works for Mailchimp, Klaviyo, and all ESPs. Free, no signup.
Upload your image
Drop your image here — then pick a preset above
or click to browse
JPG, PNG, WebP, GIF, HEIC up to 10MB
Email Image Sizes (2025)
Official recommended dimensions for every Email image type.
How to Resize an Image for an Email Header
- 1.Upload your image. Upload your image by dragging it onto the tool or clicking Browse.
- 2.Pick an email preset. Click the preset for your email layout — header, banner, or hero image.
- 3.Download and insert. Click Resize and download. Insert the image into your email template in Mailchimp, Klaviyo, or your ESP.
Email Image File Size Tip
Large email images slow down load times and can trigger spam filters. After resizing to the correct dimensions, use the Image Compressor to reduce the file size below 100KB per image. A typical email should have a total image weight under 1MB.
600 Pixels Is a Convention Older Than Most Email Clients
Email templates have settled on roughly 600 pixels of content width, and that number comes from the width of the Outlook reading pane on the monitors of two decades ago. It has survived because it still works: 600 pixels fits comfortably in every desktop client and scales down sensibly on a phone.
For a header image this means designing at 1200 pixels wide and displaying it at 600. The doubled resolution keeps it sharp on high-density screens, which is where most email is now read, while the HTML still declares the 600-pixel display width.
Height should be restrained. A tall header pushes your actual message below the fold, and in an inbox that is a real cost — many people decide whether to keep reading based only on what is visible without scrolling. Around 200 pixels of displayed height is a sensible ceiling.
Assume Images Are Blocked
A significant share of email clients block images by default until the recipient chooses to load them. If your header carries essential information — a headline, an offer, a date — a meaningful portion of your audience will never see it. Always set descriptive alt text so something useful appears in the blocked state, and never put text in an image that is not also present as real text in the email body.
Email Image Guidance
| Property | Recommendation | Reason |
|---|---|---|
| Display width | 600 px | Long-standing template convention |
| Export width | 1200 px | Sharp on high-density screens |
| Header height | Under 200 px displayed | Keeps the message above the fold |
| File size | Under 200 KB | Fast loading on mobile data |
| Format | JPG or PNG | WebP support is unreliable in email |
Frequently Asked Questions
What is the standard email header image size?
The standard email header width is 600 pixels — this is the most common email template width. Height varies from 150 to 300 pixels typically. Use 600 × 200 px for a slim header or 600 × 300 px for a larger banner.
What width should email images be?
Email images should be 600 pixels wide to match standard email templates. Wider images may require horizontal scrolling on mobile. Some modern templates use 700 or 800px, but 600px is the safest default.
What format should email images be?
JPG for photos (smaller file size, better deliverability). PNG for logos and graphics with text or transparency. Avoid GIF for large images as it increases file size significantly.
How large should email images be in file size?
Keep individual email images under 100KB for fast loading. Total email image weight should stay under 1MB. Heavy emails may be flagged as spam or load slowly on mobile.
Do email images need alt text?
Yes — many email clients block images by default. Always add descriptive alt text to your images so the email makes sense even when images are not displayed.