In 2026, around 30% of users open emails with images disabled, due to privacy policies or their email client's settings. Without alt text filled in, these recipients see empty boxes instead of your offers, which severely hurts your newsletter's conversion rate.AI automates writing descriptions for all your graphics, preserving the email's meaning and accessibility no matter how it's displayed.
Why alt text matters in 2026
- User experience when graphics are blocked. Email clients like Outlook and Apple Mail often hide images by default. Clear alt text conveys the gist of your offer before the recipient even decides to load the images.
- Content accessibility. Screen readers read descriptions aloud to visually impaired users. Without alt text, this audience loses all context for the email and can't engage with your offer.
- Deliverability. Spam filters analyze the ratio of text to graphics. Filled-in alt text lowers the risk of landing in spam, since the email looks high-quality and safe to the algorithms.
When alt text is required
The main rule: only describe elements that carry meaning.
- Needed for: promo banners, product photos, charts and diagrams, benefit icons, graphic call-to-action buttons.
- Not needed for: decorative elements, dividers, background textures, and technical corner-rounding overlays. Leave the description field empty for elements like these, so screen readers automatically skip over them.
Important: when working on the design, take into account how elements render across different interfaces. For more, see the article: How to Optimize Images for Emails in Dark Mode.
Bad vs. good alt text
Effective alt text should be concise (under 125 characters) and convey context, not just list the objects in a photo.
Image type | Bad example | Good example | Comment |
|---|---|---|---|
Promo banner | alt="banner_1" | alt="40% off all jackets until October 10" | Conveys the key offer and the deadline. |
Product in a grid | alt="sneakers" | alt="Nike Air Zoom running shoes, blue" | Helps identify the product. |
Infographic | alt="chart" | alt="AI speeds up email coding 2.5x" | States the takeaway instead of describing the visual. |
CTA button | alt="button" | alt="Download the free marketing guide" | Mirrors the call to action. |
Prompts for generating alt text
For good results, an AI needs specific input. Without it, AI produces bloated descriptions that overload screen readers and don't fit the email's layout.
The formula for an effective prompt
[Role] + [Description of the graphic] + [Text on the image] + [Email context] + [Character limit]
- Role: sets a professional, concise style (for example, "an email marketing expert").
- Description of the graphic: factually lists the important objects, colors, and materials, with no metaphors.
- Text on the image: conveys the exact wording of the offer or call to action.
- Email context: explains the purpose (promotion, trigger, news hook) so the AI picks the right emphasis.
- Character limit: a technical constraint (up to 100–125 characters) so it displays correctly in email clients.
1. Main banner
"You're an email marketing expert. Write alt text for a banner. It shows a woman in an office and the text 'AI course: starts September 1.' Emphasize the date and topic. Limit: 80 characters."
Result: AI course starts September 1 — training for professionals.
2. Product photo
"You're an email expert. Describe this product photo: a leather tote bag, khaki color, nubuck material. It's a product card in a roundup email. Limit: 70 characters."
Result: Khaki tote bag made of genuine nubuck leather.
3. Benefit icons
"You're an email expert. Write a description for an icon labeled 'Free shipping on orders over 5,000 rubles.' Convey the terms. Limit: 60 characters."
Result: Free shipping on orders over 5,000 rubles.
For more on how to use AI's capabilities for writing newsletter copy, check out our article. It'll definitely save you time preparing every email.
4. Complex illustration or animation (GIF)
"You're an email expert. Describe an animation where calendar pages flip and the text 'Your discount is expiring' appears. Context: an abandoned cart trigger. Limit: 90 characters."
Result: Animated reminder that your discount is about to expire.
For more on creating graphics, see the overview: AI Tools for Generating GIFs in 2026.
5. Graphic button
"You're an email expert. Write alt text for an image-based button reading 'Book a hotel at a discount.' Context: a travel email. Limit: 50 characters."
Result: Button to book a hotel at a promotional price.
How to add alt text in Letteros
In the Letteros email builder, working with descriptions is built into the image-editing interface — no need to dig into the code:
- Select the image block.
- In the settings menu on the right, find the "Alt text" field.
- Paste in the AI-generated version, or use the built-in AI tool.
Leave the description field empty for decorative elements. The system will automatically add the correct technical attribute to the code. Before sending, check the email in preview mode with images turned off, to make sure the text still reads coherently.
Pre-send checklist
- Every meaningful image has alt text filled in.
- The description doesn't repeat a caption underneath the image, to avoid duplication for screen readers.
- The text doesn't exceed 125 characters.
- The description doesn't contain unnecessary words like "image," "logo," or "photo."
- Every graphic button contains a clear call to action.
After setting up all the technical attributes and preparing your content, the final step should always be a spam-filter check. For how to do that, see: Checking Your Email Copy for Spam Triggers in 2026.
Want to streamline your coding process? Combine AI for content generation with Letteros for quickly assembling professional emails.