Images are an important part of any website. They help to illustrate and complement the content, making it more attractive and easier to understand. However, images can also be responsible for slowing down a website.
When images are not optimized correctly, they can significantly increase website loading time, negatively impacting user experience and potentially even harming search engine ranking.
What are optimized images?
Optimized images are those that have been compressed to reduce file size without significantly compromising visual quality. This is done through techniques such as:
- Reducing the resolution to the required size.
- Data compression (lossy or lossless)
- Removing unnecessary metadata
- Choosing the appropriate file format
- Use of modern formats like WebP and AVIF
Before and After Optimization
Original image (JPEG)
Optimized image (WebP)
Benefits of Optimized Images
Improves Loading Time
When images are optimized correctly, they load faster, which improves the user experience and can help improve search engine ranking. Google considers loading speed as a ranking factor.
Improves website usability.
A faster and more responsive website is easier to use and can help keep users engaged. When images are optimized, users don't have to wait long to see the content, which can help reduce bounce rate and increase time spent on the site.
Reduces Hosting Costs
Optimized images take up less disk space, which can help reduce website hosting costs. When a website contains many large and unoptimized images, this increases costs because the server needs more space and bandwidth to transfer these files.
"A 1-second delay in loading time can result in a 7% drop in conversions."
— Akamai Study
Image Formats
Choosing the correct format is essential for optimization. Each format has its advantages and is best suited for specific image types:
Joint Photographic Experts Group
Lossy compression, ideal for photographs with many colors and gradients..
Portable Network Graphics
SIt supports transparency, ideal for logos and images with few colors..
Web Picture Format (Google)
Modern format, 25-35% smaller than JPEG/PNG with the same quality..
Scalable Vector Graphics
Vector format, infinitely scalable without loss of quality..
AV1 Image File Format
Newer and more efficient format, up to 50% smaller than JPEG.
Graphics Interchange Format
Supports simple animations, limited to 256 colors..
Optimization Techniques
Compress the images before uploading.
Before uploading, compress the images to reduce the file size. There are several free online tools that can help with this task.
Reduce the image resolution.
Images with very high resolution increase the file size. Reduce the resolution to the actual size that will be displayed on the website.
Use appropriate formats.
Use JPEG for photographs, PNG for images with transparency, SVG for vectors, and consider WebP/AVIF for maximum compression with good quality.
Remove unnecessary metadata.
The images contain metadata (author, date, location) that increases the file size and is not required for display on the website.
Implement lazy loading
Load the images only when they are about to enter the user's visible area, reducing the initial page load time.
Optimization Tools
TinyPNG
Free online compression
Squoosh
Google app with comparison
ImageOptim
Desktop app for Mac
ShortPixel
Plugin WordPress
Cloudinary
CDN with automatic optimization
ImageMagick
CLI for automation
Do you need to optimize your website?
WD Seven develops fast and optimized websites for better performance.
Speak with Our ExpertsConclusion
Images are an important part of any website, but it's crucial to use them properly to ensure the best user experience. Using optimized images can help improve website loading time, usability, and reduce hosting costs.
There are several techniques that can be used to optimize images, including file compression, resolution reduction, appropriate format selection, metadata removal, and the use of automatic optimization tools.
Summary: Optimization Checklist
1. Compress before uploading → 2. Use the necessary resolution → 3. Choose the correct format → 4. Remove metadata → 5. Implement lazy loading → 6. Consider WebP/AVIF → 7. Use automatic optimization tools.
