Image, Video & Media SEO
Images, videos, and other media elements enrich the user experience and provide additional opportunities for search visibility. Optimized media appears in image search, video search, and can enhance regular SERP listings.
This lesson covers the seven media optimization areas (leaves 4.5.1–4.5.7): image file names, alt text optimization, image captions, image dimensions, image compression, video embed optimization, and media transcript optimization.
After this lesson you can optimize images, videos, and media elements for search visibility, accessibility, and page speed — earning traffic from image search, video search, and rich results.
Why This Matters
- Image search can be a significant traffic source. Optimized images may appear in Google Images, discovery surfaces, and rich results.
- Videos can appear in video carousels, feature snippets, and Google Discover.
- Media optimization also contributes to page speed (image compression) and accessibility (alt text, transcripts).
Image File Names
Image file names provide search engines with context about the image content.
File name best practices:
| Practice | Example |
|---|---|
| Descriptive, not generic | email-segmentation-example.png not IMG_12345.png |
| Include relevant keywords | cart-abandonment-recovery-email.png |
| Use hyphens between words | my-image.jpg not my_image.jpg or myimage.jpg |
| Keep concise but descriptive | 3-6 words is adequate |
| Avoid stop words | Remove "a", "an", "the" unless necessary |
| Match image content | File name should describe what the image shows |
File name patterns by image type:
| Image Type | Example File Name |
|---|---|
| Screenshot | gsc-performance-report-2025.png |
| Infographic | email-marketing-statistics-2025.png |
| Product photo | widget-pro-2000-front-view.jpg |
| Diagram | email-funnel-stages-diagram.png |
| Team photo | marketing-team-2025.jpg |
Alt Text Optimization
Alt text (alternative text) is an HTML attribute that describes an image for accessibility and search engines.
Alt text best practices:
| Practice | Recommendation |
|---|---|
| Describe the image accurately | Write what the image shows, not what you want it to rank for |
| Include target keyword (naturally) | If the keyword fits the image description, include it |
| Keep concise | 5-15 words (125 characters maximum) |
| Do not keyword stuff | "Email marketing software dashboard showing campaign analytics" not "email marketing software email tool marketing platform analytics dashboard" |
| Context matters | Alt text should be relevant to the surrounding content |
| Be specific | "Line chart showing email open rate increase from 18% to 32% over 6 months" not "Chart" |
Alt text by image type:
| Image Type | Alt Text Example |
|---|---|
| Product photo | "Widget Pro 2000 in matte black finish" |
| Screenshot | "Screenshot of email segmentation settings in Mailchimp" |
| Infographic | "Infographic: Email marketing ROI statistics by industry" |
| Icon/logo | "ExampleCorp logo" |
| Chart | "Bar chart comparing email open rates across four industries" |
Accessibility note: Alt text is essential for screen readers. Users with visual impairments rely on alt text to understand image content. Never omit alt text.
Image Captions
Image captions are text displayed below or near the image. They are visible to all users.
Caption best practices:
| Practice | Recommendation |
|---|---|
| Add value | Captions should provide additional context, not repeat alt text |
| Use naturally | Captions are read by users; write for humans |
| Include keyword context (optional) | If the caption naturally fits the page topic |
| Keep short | 1-2 sentences maximum |
When to use captions:
- Images that contain complex information (charts, diagrams).
- Images that benefit from additional explanation.
- Decorative images typically do not need captions.
Image Dimensions
Image dimensions affect layout stability (CLS), page load time, and user experience.
Dimension best practices:
| Practice | Recommendation |
|---|---|
| Set explicit width and height | Prevents CLS — always include width and height attributes in <img> tag |
| Match display size | Do not upload 3000px wide images to display at 300px — resize before uploading |
| Use responsive image techniques | srcset attribute serves different sizes for different viewports |
| Maintain aspect ratio | Landscape images: 16:9 or 4:3 for content images |
| Thumbnails | 150x150px minimum, maintain aspect ratio |
Responsive image example:
<img src="image-800.jpg"
srcset="image-400.jpg 400w, image-800.jpg 800w, image-1200.jpg 1200w"
sizes="(max-width: 600px) 100vw, (max-width: 1200px) 50vw, 800px"
width="800" height="450"
alt="Email campaign dashboard showing analytics">
Image Compression
Image compression reduces file size without significantly degrading quality.
Compression techniques (from Module 3, Lesson 3.5.4):
| Technique | Typical Reduction | Quality Impact |
|---|---|---|
| Lossy compression (JPEG quality 80-85%) | 40-60% | Minimal visible loss |
| WebP format | 25-35% smaller than JPEG | Same or better quality |
| AVIF format | 50% smaller than JPEG | Same or better quality |
| Resize to display dimensions | 50-90% | No quality impact |
| Remove metadata (EXIF) | 5-10% | No visual impact |
| Lazy loading below-fold images | Variable | No visible impact |
Compression workflow:
- Upload images at the largest display size needed.
- Convert to WebP (or AVIF where supported) with lossy compression.
- Use responsive images (
srcset) to serve correct sizes. - Apply lazy loading to below-fold images.
- Verify image quality is acceptable and file sizes are reduced.
Video Embed Optimization
Video content can appear in Google Video search and rich results.
Video embed best practices:
| Practice | Recommendation |
|---|---|
| Use schema markup | VideoObject schema with name, description, thumbnail, duration, upload date |
| Host on optimized platform | YouTube or Vimeo for reliable hosting, or self-host with proper schema |
| Include a transcript | Text version of video content for indexing |
| Use descriptive file name | email-deliverability-tips.mp4 |
| Set a compelling thumbnail | Custom thumbnail (not auto-generated) with relevant imagery |
| Enable embedding | Allow others to embed your video for distribution |
| Add video sitemap | Include video URLs in a specialized video sitemap |
VideoObject schema example:
{
"@context": "https://schema.org",
"@type": "VideoObject",
"name": "How to Improve Email Deliverability",
"description": "A 10-minute guide to improving email deliverability in 2025.",
"thumbnailUrl": "https://example.com/video-thumbnail.jpg",
"uploadDate": "2025-06-15",
"duration": "PT10M30S",
"contentUrl": "https://example.com/video.mp4",
"embedUrl": "https://www.youtube.com/embed/abc123"
}
Media Transcript Optimization
Transcripts make audio and video content accessible and indexable.
Transcript best practices:
| Practice | Recommendation |
|---|---|
| Include full transcript | Complete text of all spoken content in the video/audio |
| Place on the same page | Transcript should be visible on the video page |
| Use structured format | Paragraph format with speaker labels for multi-speaker content |
| Include timestamps | Optional for long videos (helps users navigate) |
| Optimize for keywords | Transcript naturally includes topic-relevant language |
Transcript benefits:
- Makes video content indexable (Google cannot watch videos, but it can read transcripts).
- Supports accessibility for hearing-impaired users.
- Improves user engagement (users can scan the transcript before watching).
- Provides additional content for search engines to understand and rank.
Workflow
- Audit current images: Crawl site, check for missing alt text, oversized images, non-descriptive file names.
- Fix critical issues: Add alt text to all images, rename files where practical.
- Compress and resize: Optimize images for page speed.
- Add video schema: Implement VideoObject schema for all video content.
- Add transcripts: Include text transcripts for video and audio content.
- Monitor: Check GSC Image search performance and video indexing.
Common Mistakes
Keyword-stuffed alt text (e.g., "email marketing software tool platform automation features benefits") is spammy, harms accessibility for screen reader users, and may trigger quality filters. Write accurate descriptions that genuinely describe the image content.
- Keyword-stuffed alt text:
"email marketing software tool platform automation features benefits"is spammy and unhelpful for accessibility. - Uploading full-size images: 4000px wide photos displayed at 300px waste bandwidth and slow page load.
- Missing alt text on important images: Screen readers will read the file name (which may be unhelpful or nonsensical).
- Skipping video schema: Without schema, Google may not recognize the video content on the page.
- No video transcript: The video content is invisible to search engines without indexable text.
Checklist
- All images have descriptive, keyword-relevant file names.
- All images have alt text (accurate description, not keyword-stuffed).
- Images have explicit width and height attributes (CLS prevention).
- Images are compressed (lossy, next-gen format, resized to display dimensions).
- Below-fold images use lazy loading.
- Video content has VideoObject schema markup.
- Video content has an indexable transcript on the same page.
- Image search performance is monitored in GSC.