This article covers the supported file formats, size limits, and technical recommendations for assets used in Activator — including emails, eDetailers, and Briefs.
Emails
Key Constraints
-
Maximum image width: 600px (images wider than this will scale down to fit the email container)
-
Maximum file size: 2MB per image or GIF
-
Images are sized by width only — height is not cropped or adjusted automatically. Crop images to the correct dimensions before uploading.
-
Images with embedded text cannot be edited in Activator. Where possible, minimise the use of text-on-image assets.
-
SVGs are not supported for email assets.
Email Media Asset Recommendations
|
Asset type |
Dimensions |
File format |
Resolution |
|---|---|---|---|
|
Header image |
Width: 600px Max height: 300px (taller headers push content below the fold) |
PNG or JPG |
Recommended: 72–150 ppi Up to 300 ppi if the image appears blurry, provided the file stays under 2MB. |
|
Half-side image |
Width: 280–300px (use 280px to leave breathing room between the image and the adjacent element) |
PNG or JPG |
Same as header image |
|
Icon |
Recommended: 50–200px wide (can be up to 600px — the image container controls display size, but larger files increase email weight) |
PNG (for transparent backgrounds) SVG is not supported for email |
— |
Permitted Email File Extensions
-
Images: .bmp, .gif, .jpeg, .jpg, .png, .svg, .webp
eDetailers and Briefs
Key Constraints
-
Maximum file size: 2MB per image or GIF
-
Maximum video file size: 200MB
eDetailer/Brief Media Asset Recommendations
|
Asset type |
Dimensions |
File format |
Resolution |
|---|---|---|---|
|
Full-size image |
Recommended minimum width: 2388px (covers iPad Air, iPad 10.2", and iPad Pro 11") |
PNG or JPG |
150–300 ppi (balance quality and file size; high-resolution images increase loading time) |
|
Video |
— |
.avi, .mp4, .mpeg, or .mov |
— |
Permitted eDetailer/Brief File Extensions
-
Images: .bmp, .gif, .jpeg, .jpg, .png, .svg, .webp
-
Audio: .m4a, .mp3, .wav, .wma, .flac
-
Video: .m4v, .mov, .mp4, .wmv, .mpeg, .mpg, .avi
Optimising File Size
If an image exceeds the 2MB limit, use the following strategies to reduce its size.
Step 1: Compress
Use a compression tool first:
-
TinyPNG (tinypng.com) — excellent for PNGs and JPGs
-
Squoosh (squoosh.app) — compress and resize in one step
Step 2: Convert to a more efficient format
If compression alone is not enough, convert to a smaller format:
-
Emails: Convert BMP and PNG to WebP (25–50% size reduction). Convert JPG to WebP if further reduction is needed.
-
eDetailers/Briefs: Images: same as above (WebP is best). Audio: convert WAV/FLAC to MP3 (128–192 kbps). Video: convert AVI/WMV to MP4 (H.264 codec).
Recommended tool for non-image formats: cloudconvert.com
Step 3: Resize to display dimensions
Reduce images to the actual display size × 2 (for retina screens). For example, if an image is displayed at 400px wide in an email, save it at 800px maximum. For email, this typically means 600–1200px wide. Anything larger adds unnecessary weight.
CDN Links for Email Images
Unlike eDetailer slides, email images are loaded via CDN rather than embedded directly. Using CDN-hosted images provides several benefits:
-
Faster image loading for recipients
-
Reduced overall email file size
-
Improved display consistency across email clients
-
Images are cached, which improves performance on repeated opens
Important: Always use public, stable CDN URLs for email images. Temporary or internal URLs (such as Vault uploads, local file paths, or private S3 buckets) may break when recipients open the email. If a public CDN is not available, Base64 image embedding is an acceptable alternative.
Additional Notes
-
Where assets are saved may vary by organisation. Check your local guidelines if certain save locations are unavailable.
-
Not all media types may be available in your project — access to elements is defined by the creator of the Design System.
-
Images cannot be edited in Activator. Use third-party software (such as Photoshop or Squoosh) to prepare and crop images before uploading.