Best Image Sizes for Your Website
If you want your website to load quickly and look professional, using the right image sizes is essential. Oversized or inconsistent images can slow down your site, affect layout, and hurt your SEO. In this post, I will walk you through the best image sizes for common website content types, and give you tools to resize and optimize your images.
What Is an Aspect Ratio?
An aspect ratio is the relationship between the width and height of an image. For example, a 3:2 aspect ratio means the width is 1.5 times the height. Keeping your images consistent in aspect ratio helps ensure your pages look clean and uniform.
My Favorite Image Resizing Tool
To resize images to exact pixel dimensions, I recommend Adobe’s Free Online Image Resizer. It is simple, free, and lets you enter specific pixel values for precision.
Recommended Image Sizes by Content Type
- Blog Post Images (3:2 aspect ratio)
- Horizontal Long Edge: 1200px
- Vertical Long Edge: 800px
- Background or Header Images
- Horizontal Long Edge: 1920px
- Keep the vertical size under 1200px for faster loading
- Logo Images
- Horizontal Long Edge: 300px
- Use a transparent PNG or SVG if possible
- Thumbnail Images
- 250px x 250px
- Product Images (1:1 square aspect ratio)
- 1500px x 1500px
- All product images must use the same aspect ratio to prevent layout issues on product pages
Optimize for Web Performance
After resizing your images, run them through TinyPNG to compress the file size without losing quality.
- Goal: Keep file sizes under 250KB whenever possible
- Larger background or product images may go over 250KB—just get as close as you can
- Use JPG or WebP for smaller file sizes
- Use PNG or WebP only when a transparent background is required
Image Naming and ALT Text Tips
- File Names:
Use your blog title or product name- Avoid spaces and special characters
- Use hyphens or underscores instead (e.g., black-denim-jacket.jpg)
- Keep it short—remove filler words like the, and, it, is, at
- ALT Text:
Every image should include alt text for accessibility and SEO- Describe the image in a short, clear sentence
- Example: “Woman in a navy prom dress standing in front of a mirror”