When you upload images to the Diobox Email Builder, the platform automatically optimizes them in the background on your behalf. These optimizations are designed to improve email performance without requiring any extra steps.
The process ensures that email campaigns are lightweight, fast-loading, and visually consistent across devices and email clients. This happens immediately upon upload, meaning that even the preview displayed in the editor is already the optimized version, not the original large file.
Why Image Optimization Matters
Large or unoptimized images can create issues such as:
Slow loading times for recipients, especially on mobile networks
Higher chances of being flagged as spam due to heavy email sizes
Lower engagement if recipients abandon the email before images finish loading
Inconsistent rendering in certain email clients
By optimizing your images automatically, Diobox helps ensure your campaigns load quickly and deliver reliably without requiring extra effort from you.
How Diobox Optimizes Your Images
Resizing
Uploaded images are resized to a maximum width of 1240 pixels. This is large enough for high-resolution displays but prevents oversized files that add no visible benefit.
Smart Format Handling
Photos uploaded as heavier formats (like PNG) are converted to JPG for efficiency.
Logos, icons, or text graphics that require sharp edges or transparency remain in PNG format to preserve quality.
Advanced Compression
Compression can reduce certain files by up to 95% without any visible loss of quality. This means images appear identical to the human eye but load significantly faster.
In addition, Diobox supports modern file formats such as AVIF and WebP whenever supported by the recipient’s device or email client. If these are not supported, fallback formats (such as PNG or JPEG) are used automatically to ensure compatibility.
The Result
By handling this optimization behind the scenes, Diobox ensures:
Faster load times for all recipients
Smaller, more efficient emails (improving deliverability)
High-quality images that render consistently across devices
A simplified workflow, since the preview shown in the editor is already the optimized version