Introduction
Images are an important part of any website. They make content more attractive, help explain ideas visually, and improve the overall experience for visitors. But if images aren’t handled properly, they can also slow your website down and hurt your search engine rankings.
Two of the most common problems with images are:
- Large file sizes, which increase loading time.
- Missing or unclear alt text, which affects SEO and accessibility.
Search engines prefer websites that load fast and are easy to understand. That’s where image optimization becomes important in the part of Technical SEO. By resizing, compressing, and properly tagging your images, you can improve both speed and search performance.
To make this easier, we’ve developed a tool that helps check your website images. It tells you which images are too large, which are missing alt text, and how to fix them for better performance.
Let’s take a closer look at what matters when it comes to image optimization—and how you can make these changes step-by-step.
Key Image Optimization Factors
1. File Size
Large image files are one of the biggest reasons websites load slowly. When someone visits your page, every image has to be downloaded to their device. The bigger the image file, the longer it takes to load.
A slow-loading page can:
- Frustrate users
- Increase bounce rates (when people leave quickly)
- Lower your search engine ranking
That’s why keeping file sizes small is important. Our tool shows the “Largest Image Size (KB)” for every image on your page. This helps you quickly find and fix the ones slowing your site down the most.
2. Alt Tags
Alt tags (short for “alternative text”) are descriptions added to images. These tags serve two purposes:
- They help people using screen readers understand what the image shows.
- They give search engines more information about your content.
For example, instead of naming an image “image1.jpg,” a good alt tag would be “Red running shoes for women.”
Our tool scans all your images and shows which ones are missing alt text or have poor descriptions. This makes it easier to improve your image SEO in just a few minutes.
3. File Format
Choosing the right image format also affects size and speed. Here’s a quick overview:
- JPEG: Best for photos; good quality with small file size.
- PNG: Good for images with transparent backgrounds; larger file sizes.
- WebP: A modern format that offers high quality and smaller file sizes; supported by most browsers.
Whenever possible, it’s best to use WebP for speed and JPEG for compatibility. Our tool helps you spot old or heavy formats and suggests better options.
Step-by-Step Optimization Process
Here’s how you can optimize your images for both SEO and speed.
Step 1: Use the Tool to Identify Large Images
Start by running your website through our image checker tool. The tool will scan all the images on your page and list them in a table. You’ll see:
- File name
- File size in kilobytes (KB)
- Whether an alt tag is present
- The image format (JPEG, PNG, WebP)
Step 2: Compress Images Without Losing Quality
Once you’ve found the large images, you can compress them using free tools like TinyPNG, Squoosh, or ImageOptim. These tools reduce the file size while keeping the image quality high.
Our tool doesn’t compress the images directly, but it highlights the ones that need compression so you can fix them quickly.
Tip: Try to keep images below 200 KB for best results, especially on mobile.
Step 3: Add Descriptive Alt Text
Next, review the images that are missing alt text or have weak descriptions. Use simple, clear words to describe what’s in the image. Think about what someone would need to know if they couldn’t see the picture.
Example from the tool:
- Image: “shoes-banner.jpg”
- Suggested Alt Text: “Close-up of red women’s running shoes on a trail”
Good alt text should:
- Be accurate
- Include important keywords
- Avoid stuffing extra or unrelated words
You can edit the image tags directly in your website’s HTML or content management system.
Real Results with Our Tool
Case Study: Speed Improvements from Image Optimization
One of our users had a slow-loading e-commerce site. The home page had many product images—some were over 1MB each. After scanning the site with our tool, they found:
- Several images above 800 KB
- Dozens of missing alt tags
- All images in PNG format, even though they didn’t need transparency
They followed the steps above:
- Compressed all images to under 200 KB
- Added keyword-rich alt text
- Switched formats to JPEG and WebP
Result:
- Page load time dropped from 6.5 seconds to under 2.5 seconds
- Bounce rate decreased by 20%
- Organic traffic improved by 18% in 3 weeks
How Our Tool Helps
Our image optimization features include:
- Listing all images on the page
- Showing the largest image size
- Highlighting images without alt text
- Providing details in a downloadable Excel report
- Integration with PageSpeed metrics, showing how much images affect overall speed
You don’t need any coding knowledge. Just enter your URL, run the scan, and view the results. It’s easy to share the report with your developer or content team.
Conclusion
Image optimization is one of the simplest ways to boost your website’s performance. By compressing large files, using the right formats, and adding helpful alt text, you improve speed, search visibility, and user experience—all at once.
With the help of our tool, you can spot issues quickly and fix them without guesswork. Whether you run a blog, online store, or business website, these steps can make a big difference.
Start your free image audit today and see how much faster your website can be.
Bonus Tips for Even Better Results
- Lazy loading: Only load images when they’re needed (especially for long pages).
- Responsive images: Use different image sizes for different screen types (mobile vs. desktop).
