When I first started learning about SEO, I used to focus only on keywords, titles, and backlinks. I never paid much attention to images. I thought an image is just an image, and as long as it looks good, everything is fine.
But after spending some time understanding how websites work, I realized that image size also plays an important role in on-page SEO. One question that confused me a lot was, “Does an image size over 100 KB matter?”
If you have the same question, don’t worry. I also didn’t understand why image size matters so much. In this blog, I will explain everything in simple language.
Why Do Images Matter on a Website?
Images make a blog more attractive and easier to understand. They help readers stay longer on a page and make content look less boring.
But images also take up space. When someone opens your page, the browser has to load all the images along with the text. If the images are too large, the page may take more time to load.
And this is where SEO comes into the picture.
Does an Image Size Over 100 KB Matter?
The simple answer is yes, but not always.
Having an image larger than 100 KB is not automatically bad for SEO. Google does not punish websites just because an image is 120 KB or 150 KB.
What really matters is how image size affects your website’s loading speed.
If your page loads quickly and provides a good experience to visitors, then having some images above 100 KB is perfectly fine.
Why Does Image Size Affect SEO?
Google wants users to have a good experience. Nobody likes waiting for a page to load.
Large images can make a page slower, especially for people using mobile devices or slower internet connections.
A slow website can lead to:
- Higher bounce rates
- Poor user experience
- Lower page speed scores
- Fewer page views
- Possible ranking problems
That’s why image optimization is considered an important part of on-page SEO.
Is 100 KB a Magic Number?
Not really.
Many people think every image must be below 100 KB. I also believed this at first, but the truth is different.
There is no official Google rule saying that images must stay under 100 KB.
Sometimes:
- A simple image may be only 50 KB.
- A high-quality featured image may be 150 KB.
- An infographic may be 200 KB or more.
The goal is not to follow a fixed number. The goal is to keep images as small as possible without making them look blurry.
What Happens If Images Are Too Large?
Suppose you upload a 4 MB image directly from your phone or camera.
Now imagine you have five such images on one page.
That means visitors need to download around 20 MB of data before the page fully loads.
This can make your website slow, and some visitors may leave before reading your content.
Slow websites can affect:
User Experience
People want fast websites. If your page takes too long to open, visitors may leave and look somewhere else.
Mobile Performance
Many users browse websites on their phones. Large images can slow down loading speed even more on mobile devices.
Core Web Vitals
Google pays attention to page experience. Heavy images can affect metrics related to loading speed and visual performance.
What Is the Ideal Image Size?
There is no perfect size for every image, but many website owners try to follow these ranges:
- Small images: 30 KB to 80 KB
- Blog images: 80 KB to 150 KB
- Featured images: 100 KB to 200 KB
- Large banners: 150 KB to 300 KB
These are only general suggestions, not strict rules.
Does Image Quality Matter Too?
Yes.
Making images too small just to reduce file size is not a good idea.
I once compressed an image too much, and it became blurry. It looked unprofessional and reduced the overall quality of the blog.
A balance between quality and file size is important.
Good-looking images create a better experience for readers.
Which Image Formats Are Best?
Different image formats have different file sizes.
JPEG
JPEG images are commonly used for blog posts and photographs. They usually provide good quality with smaller file sizes.
PNG
PNG files are useful when transparency is needed, but they are often larger than JPEG files.
WebP
WebP is one of the best formats today because it provides high quality while keeping file sizes smaller.
Many websites now use WebP images to improve loading speed.
How Can You Reduce Image Size?
Here are some simple ways:
Resize Images Before Uploading
If your blog image only needs a width of 1200 pixels, uploading a 4000-pixel image is unnecessary.
Resizing images can reduce file size significantly.
Compress Images
Image compression tools can reduce image size while maintaining quality.
Use WebP Format
Converting JPEG or PNG images to WebP often saves space.
Avoid Uploading Original Camera Images
Photos taken from modern phones are usually very large. It is better to optimize them before uploading.
Will Large Images Stop My Website From Ranking?
No.
Google does not rank websites based only on image size.
SEO depends on many factors, such as:
- High-quality content
- Keywords
- User experience
- Mobile friendliness
- Website speed
- Internal linking
- Backlinks
Image optimization is just one part of the bigger picture.
So don’t panic if some of your images are above 100 KB.
Should Every Image Be Under 100 KB?
Not necessarily.
I used to think every image had to stay below 100 KB, but I learned that there is no need to follow such a strict rule.
Instead, ask yourself:
- Does the image load quickly?
- Does it look clear?
- Does it help readers understand the content?
- Is the file size reasonable?
If the answer is yes, then you are already doing well.
My Simple Rule
Whenever I create blog images, I try to:
- Keep image dimensions reasonable.
- Compress images before uploading.
- Use WebP format whenever possible.
- Avoid unnecessary large files.
- Focus on user experience instead of chasing a specific number.
This simple approach works well and helps keep pages fast.
Final Thoughts
When I first heard people saying that images should always be below 100 KB, I became confused. I thought crossing that number would hurt my SEO.
But after learning more, I understood that 100 KB is not a strict limit.
An image larger than 100 KB is perfectly fine if it does not slow down your website. Google cares more about page speed and user experience than about a specific image size.
So, instead of worrying about reaching an exact number, focus on creating images that look good, load quickly, and provide a better experience for your visitors.
That is what really matters for on-page SEO.
