Image compression is reducing the file size of an image while keeping acceptable visual quality. In email, compression is one of the most effective ways to improve performance because images are often the largest assets in a message. Well-compressed images load faster, reduce bandwidth costs, and lower the chance of clipping due to oversized templates.
Compression as Part of Performance
Compression is a key part of image optimization, but it is also a direct lever for email load time. When images are heavy, the email feels slow even if the HTML is small. Compression reduces that initial wait. It also decreases the risk of size-related issues like clipped email and helps you stay under an email size limit.
Choosing the Right Compression Strategy
Keep an eye on artifacts around text and sharp edges, because these are the first areas where over-compression becomes obvious. If a logo looks blurry, it can harm trust. In those cases, use a cleaner format or slightly higher quality settings.
Different image types benefit from different approaches. Photos often compress well with modern formats, while UI graphics and logos may require careful handling to avoid blurriness. A practical rule is to compress until the change is barely noticeable at typical email viewing sizes. If an image is only ever displayed small, do not ship a giant high-resolution file.
Practical Compression Workflow
Establish a consistent pipeline. Define target maximum sizes for hero images, product thumbnails, and icons. Compress and then validate on real devices. If you rely on animated GIFs, treat them as special cases because they can be huge. Consider converting certain GIFs to lighter formats or replacing them with a static fallback plus a link. Track template size over time so compression remains a consistent habit rather than a one-off cleanup.
Image Compression and Topol
Topol helps teams keep templates efficient through reusable modules and predictable output, making it easier to standardize compressed assets and avoid bloated emails. Learn more at Topol or sign up at Topol signup.