Large, unoptimized images are one of the most common reasons for slow-loading websites. And when your site is slow, both users and search engines notice it – and not in a good way.
That’s where image compression comes in — a simple but vital part of technical SEO that can have a big impact on your performance.
In this post, we’ll break down how compressing images improves SEO, how to do it properly, and which tools make this process easy.
Why Image Compression Matters for SEO
Page speed is a confirmed Google ranking factor. When your pages load slowly, visitors are more likely to bounce — and Google notices that.
Uncompressed images can add megabytes to your page size, causing:
- Longer load times (especially on mobile)
- Poor performance in tools like Google PageSpeed Insights
- Lower rankings in search results
- Frustrated users who never become customers
Compressing your images is one of the easiest ways to speed up your site without sacrificing visual quality.
Best Image Formats for SEO
Whenever possible, use image formats that balance quality and file size:
- WebP: Modern format that offers high quality with small file size
- JPEG: Good for photos and gradients
- PNG: Best for images that require transparency — but large in size
WebP is recommended by Google and supported by most modern browsers. Many tools let you convert images to WebP during compression.
How to Compress Images for SEO (Step by Step)
1. Choose an Image Compression Tool
Here are a few beginner-friendly tools you can start using right away:
- TinyPNG – Free and easy; supports PNG, JPEG, and WebP
- Squoosh – Made by Google; gives you full control over compression level and file format
- ImageOptim – Excellent for Mac users who want to batch-process images
You can also use built-in tools in design apps like Canva, Figma, or Photoshop to export optimized files.
2. Compress Images Before Uploading to Your Website
Don’t rely on your CMS or theme to optimize images automatically. Compress and resize them before you upload.
Tips:
- Resize images to their actual display size
- Avoid uploading full-resolution photos from phones or cameras
- Keep file sizes ideally under 100–200 KB for standard blog images
3. Use Image Optimization Plugins (for WordPress)
If you use WordPress, you can automate image compression and WebP conversion with plugins like:
- Smush
- ShortPixel
- Imagify
- EWWW Image Optimizer
These tools compress images on upload and often convert formats as well. Some also offer lazy loading and CDN delivery.
Test Your Site’s Image Performance
After optimizing, test your site’s performance with tools like:
Recap: Image Compression Checklist for SEO
✅ Use WebP or JPEG when possible
✅ Compress images before uploading
✅ Resize to actual display size
✅ Keep file sizes small (under 200 KB when possible)
✅ Use compression tools like TinyPNG or Squoosh
✅ Install an image optimization plugin if using WordPress
✅ Test performance regularly
Want Help Optimizing Your Site’s SEO?
I offer technical SEO and content optimization services for websites targeting the Finnish market — including image optimization, speed tuning, and content audits.
👉 Looking for help with technical SEO or localized strategies? See my SEO services for the Finnish market or get in touch to learn more!
Tammivaara Digital Marketing 
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