How does ALT text factor into testing?

ALT text matters because many recipients experience your email with images blocked or slow to load:

Default blocking: Many email clients block images by default until the recipient enables them. ALT text is all they see initially.

Accessibility: Screen readers rely on ALT text to convey image meaning to visually impaired recipients.

Testing ALT text: Treat it as a variable worth testing. Descriptive versus action-oriented ALT text. Including CTAs in ALT text for key images.

Styled ALT text: Some clients support basic styling of ALT text (color, size, font). Test styled versus plain ALT text.

Measure impact by segmenting results between recipients who loaded images and those who did not, if your ESP provides this data.

ALT text is your backup headline. When images fail, good ALT text keeps the message working.