Large image files are one of the most common reasons Blogger sites load slowly.
Many beginners upload images directly from a phone, camera, or Photoshop without optimizing them first.
While Blogger automatically compresses uploaded images, preparing your files before uploading usually yields better results.
In this guide, you'll learn how to compress images before uploading to Blogger using free tools and simple settings.
Reader Note: If you are wondering why you should manually compress files when Blogger already offers built-in automation, you are not alone.
I have broken down the exact differences between file storage, post HTML, and theme templates in my master guide to Blogger image optimization.
👉 For a complete overview of Blogger images, see the complete Blogger image guide: optimization, compression & rendering.
Why compress images before uploading to Blogger
Compressing images before uploading helps:
- Reduce page loading times.
- Improve mobile performance.
- Use less bandwidth.
- Improve Core Web Vitals scores.
- Keep image quality while reducing file size.
Blogger can reduce an image file size, but it cannot change the actual shape of the picture.
If you upload a tall, vertical image where a wide, horizontal banner is supposed to be, Blogger will stretch, crop, or distort it.
Your blog will end up looking messy and unprofessional on mobile phones and computer screens.
The Golden Rule: Always crop your photo to the right shape and shrink its file size before you upload it to Blogger. Don't rely on the platform to do the heavy lifting for you!
Although Blogger compresses images automatically, starting with an optimized image gives you more control over file size and image quality.
👉 Check out which Core Web Vitals tools is more accurate: PageSpeed Insights vs Lighthouse.
3 steps to compress images before uploading to Blogger
Learning how to compress images before uploading to Blogger is simple.
Follow these three steps before uploading any image.
Step 1: Resize the image dimensions
Before compressing, make sure the image is the correct size.
- Featured images: 1200×630 pixels
- Content images: 800–1200 pixels wide
- Logos and icons: Only as large as needed
Uploading a 4000-pixel-wide image when your content area only displays 800 pixels wastes bandwidth and increases file size.
👉 Read: Blogger featured image size: use it correctly to fix blur and layout shifts to learn more about choosing the correct dimensions.
👉 You should also understand:
- Blogger post content area width: how to find & optimize it
- Know the difference between image dimensions and image file size
Step 2: Convert the image to WebP
WebP is Google's modern image format designed for websites.
Compared with JPEG and PNG files, WebP usually produces much smaller file sizes while maintaining similar image quality.
Before uploading, save or convert your image to .webp whenever possible.
👉 If you use older versions of Photoshop, see How to add WebP plugin to old Photoshop CS (32-bit Fix).
Step 3: Compress the image file
After resizing and converting to WebP, run the image through a compression tool.
Compression removes unnecessary data to reduce the file size further without noticeable quality loss.
For most Blogger images, a quality setting between 75% and 85% provides a good balance between quality and file size.
👉 Check out:
- Understanding Blogger image WebP compression: how it works
- How to convert Blogger images to WebP format for faster loading
Best free tools to compress images
1. Squoosh
Squoosh is one of the best free image optimization tools available.
- Resize images
- Convert to WebP
- Adjust compression levels
- Compare before and after quality
2. TinyPNG
TinyPNG is useful when you need to compress multiple images quickly.
Simply upload your images and download the optimized versions.
3. ImageResizer Bulk Tool
ImageResizer Bulk Tool can process multiple files at once. You can upload up to 50 images simultaneously and set a uniform Target Size in KB for all of them
Step-by-step compressing a featured image with Squoosh
Let's walk through a real-world example of how to compress a featured graphic before adding it to a new blog draft using Squoosh:
- Open your internet browser and navigate to squoosh.app.
- Drag and drop your original image file into the center of the screen.
- Look at the panel on the right side of the screen labeled Edit. Check the box that says Resize.
- Type
1200into the Width box and630into the Height box. (For supporting body content images, use a width of800). - Look at the Compress dropdown menu directly below the resize section. Change the target format selection from Browser JPEG to WebP.
- Adjust the Quality slider bar. For the vast majority of blogs, setting the quality between 75% and 80% is the sweet spot. It reduces the file weight significantly while keeping the picture completely sharp to the human eye.
- Look at the bottom right corner to see your savings. You will often see a notification showing that your file size has shrunk by 0% to 90%!
- Click the blue Download icon to save your new, ultra-light WebP image to your computer.
Now, your file is fully optimized and perfectly safe to upload directly into your Blogger editor panels.
Blogger images file sizes
There is no perfect file size because every image is different.
As a general guide:
- Featured images: 50–150 KB
- Content images: 20–100 KB
- Icons and logos: under 50 KB
If text inside the image becomes blurry after compression, reduce the compression level or increase the image dimensions.
Find out why text inside Blogger images becomes blurry and how to fix it for more help.
👉 You may also check out how to fix Blogger blurry images without slowing down your site.
If images still look blurry on high-density screens, read fixing Retina blur in Blogger: how to make images sharp on phones and high-resolution screens.
What happens after you upload the image?
After uploading, Blogger automatically creates multiple image sizes and serves different versions based on the visitor's screen size.
To understand how this system works, read Blogger image size system explained (s640 vs s1600).
If you later edit image URLs manually, be careful.
👉 Read Why manually adding -rw to Blogger post images is a trap.
Conclusion: How to compress images before uploading to Blogger
Learning how to compress images before uploading to Blogger is one of the easiest ways to improve your blog's speed and user experience.
Before uploading any image:
- Resize it to the correct dimensions.
- Convert it to WebP.
- Compress it using a free optimization tool.
These simple steps can significantly reduce file sizes while keeping your images sharp and professional.
Why compress manually if Blogger converts to WebP automatically?
You might already know that Blogger is smart enough to convert images to WebP on the fly when serving them to your readers, as I explained in my post Understanding Blogger image WebP compression: how it works.
However, doing it yourself beforehand gives you ultimate control over the compression slider—ensuring your images stay pixel-perfect without relying on Blogger's unpredictable automated algorithm.
Plus, it protects your personal Google Drive storage space from filling up with heavy, unoptimized source files.