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Product image optimization is the practice of tailoring photo sizes, formats, and descriptions on a website. It helps search engines and AI chatbots understand a page’s image content so it surfaces in relevant results. A solid product image optimization strategy may improve page loading speeds, search engine optimization (SEO), and generative engine optimization (GEO).
Why Does Product Image Optimization Matter for SEO?
When you enter a query into a search engine, its proprietary algorithm works behind the scenes to pull in relevant results. This process occurs in nanoseconds thanks to search indexing.
Search engines use bot web crawlers to index new and existing web pages for search. During the indexing process, crawlers review each page to understand its contents.
When the bot crawler detects a photo, it analyzes the image’s alt text, file name, tags, and technical details. The findings help search engines decide what queries the image is relevant to and index them appropriately. Without proper descriptors, the image can’t contend with the top results for target keywords or phrases.
A product image’s file type and format impact page loading speed and image quality. Oversized or not properly optimized images take longer for servers to retrieve. This can hurt the user experience and lead to page bounces, where a visitor leaves the page without any further engagement. Proper product image optimization dramatically reduces load speeds.
Search engines prioritize responsive image delivery that displays correctly across all screen sizes. With image optimization techniques, you can implement responsive images that autofit to a mobile user’s device type and screen.
Users don’t always prioritize text results, especially when searching for a product. Many consumers review product images to find items that fit their needs. With an optimized photo, your brand has a better chance of landing in Google Image results, resulting in more website visits and traffic.
How Do You Write Alt Text & Name Image Files Correctly?
Search engine crawlers examine the alt text and file name of every photo on a website. These attributes aren’t directly displayed to casual visitors, but they’re critical to the search indexing process.
Writing Descriptive Alt Text
Alt text describes a specific product photo. It’s interpreted by search engines for indexing in search engine results. Screen readers convert alt text to Braille or speech output for visitors using assistive technology.
Product image alt text may seem unimportant compared to the body copy visitors can easily see, but it’s actually one of the most important elements on a product page. For good results, follow these best practices:
- Include the primary keyword: Fit the primary keyword into the description naturally. For example, if your keyword is “white wooden outdoor table,” you could write “A white wooden outdoor table perfect for backyard patios.”
- Minimize character count: Search engines prioritize alt text that’s under 125 characters. Crawlers may disregard text that exceeds that character count.
- Skip file-type descriptors: Screen readers and search crawlers can distinguish between body text and images. Use alt text to summarize a product photo instead of wasting valuable characters on “image of” or “picture of.”
There are also some no-nos to look out for. Making these alt text mistakes can cost you in search engine rankings:
- Keyword stuffing: Crawlers can distinguish between natural and keyword-stuffed alt text. Use proper grammar and avoid repeating keywords within the same description.
- Empty alt attributes: Because alt text isn’t visible to most website visitors, unknowing brands may skip it entirely. Unfortunately, most crawlers can’t index an undefined image.
You may be tempted to use the same alt text across product images, especially if you sell similar items. However, duplicate alt text can penalize your page in the rankings, as search engines won’t know what’s special about one product versus another. Find ways to distinguish each product’s alt text so it highlights that item’s benefits, uses, or appearance.
Optimizing Image File Names
Image file names send a contextual signal to search engines before a page loads. They help search engines determine whether a page is related to a user’s query.
For best results, include the product’s name and relevant details, such as its color, material, and model, in the file name. Separate each descriptive word with a hyphen to avoid confusing web crawlers. For example, say you’re selling a beach umbrella. Instead of just naming the file “umbrella,” you could label it “beach-umbrella-red-stripes-plastic-model44.”
Mistakes to avoid when labeling image data files include:
- Using default camera strings: Most cameras and smartphones apply an automatic sequential name, such as IMG_4872.jpg, to photos. A search engine crawler won’t understand this undescriptive label.
- Including underscores: Web crawlers interpret underscores as a word connector instead of a space. For example, an image file named “blue_tennis_shoes” might be read as “bluetennisshoes.” Stick with hyphens, which web crawlers treat as a space.
Another blunder to look out for is using generic names, such as “product1.jpg.” Give every image a descriptive, tailored name that reflects its contents.
What Image Formats & File Sizes Should You Use?
The technical aspects of product photos affect page loading times and image quality. Use these tips to select the best image format and file size for your product photos.
Choosing the Right Image Format
When selecting an image format, consider your use case. Each file format is designed to achieve a specific purpose. Common use cases and their optimal format include:
- Standard product photos: The JPEG image format serves as an all-purpose file type for most product images. Its high-quality resolution is suitable for colorful products.
- Transparent backgrounds: A PNG image is ideal for displaying a product image with a transparent background.
- Reduce load speeds: If a fast initial page load time is your goal, opt for WebP file types, supported by most browsers.
AVIF is an emerging image file type that offers strong compression and high-quality image resolution. It’s supported on major browsers, including Chrome, Safari, Edge, and Firefox. However, visitors using older devices or browsers may not be able to view AVIF images.
Compressing Without Losing Quality
Before uploading an image to your website, check its file size. Images under 150 KB deliver the fastest load speeds without impacting visual quality. It’s best to keep image dimensions at their actual width and height rather than trying to scale them down, as that may actually increase their file size.
If your pictures exceed the 150 KB threshold, use a reliable image optimizer to compress images. Tools such as Squoosh and ShortPixel are user-friendly and get the job done.
How Do Product Images Affect Core Web Vitals?
Two key website metrics are affected by product images: Largest Contentful Paint (LCP) and Cumulative Layout Shift (CLS).
LCP reflects how long it takes a page to load based on its main image element. For online stores, this is usually a hero or product photo. Using image formats such as WebP and AVIF can reduce long LCP times. If a page displays multiple images, enabling lazy loading for off-screen images can improve load speeds.
CLS measures the frequency of unexpected layout shifts during page loading or scrolling. Defining image dimensions in code minimizes layout shifts as images load. Using the HTML attribute “srcset” on your page enables browsers to select the appropriate image size based on a visitor’s device and screen.
Make Product Image Optimization a Part of Your SEO Strategy
Product-oriented companies need a well-defined image strategy to surface in search engine and chatbot results. ELK Marketing specializes in SEO, GEO, and website development. Get in touch with us today to start scaling your store for growth.
FAQs
Does alt text directly impact search rankings?
Yes, search engine crawlers use alt text to index a page and its images for relevant user queries. Optimizing alt text for keywords and product descriptions strengthens page relevance signals and boosts visibility in image searches.
Should every product image on a page have alt text?
Every product image should include unique and descriptive alt text, including gallery and zoom images. As a best practice, keep alt text to 125 characters and include target keywords naturally.
Can large image file sizes cause a page to fail Core Web Vitals?
Oversized images are a common reason why websites suffer from poor LCP scores or failed Core Web Vitals audits. Using file types such as AVIF or WebP can improve LCP scores and loading speeds.
