Compression and resizing both reduce image weight, but they do it in different ways. Compression changes how efficiently the image data is stored, while resizing changes the number of pixels in the image itself.
That means the right fix depends on whether the problem is upload size, oversized dimensions, slow loading, or all three at once.
What Compression Changes
Compression reduces file size without necessarily changing the displayed width and height. It is a strong first move when the dimensions are already correct but the asset is still too heavy.
What Resizing Changes
Resizing changes pixel dimensions. It matters most when an image is far larger than the place where it will actually appear, such as a hero image being uploaded as a print-sized original.
When You Usually Need Both
Many web assets benefit from resizing first and compression second. That workflow removes unnecessary pixels and then reduces the remaining file weight further.
- Oversized originals for web or email
- CMS uploads with strict file limits
- Social assets that need predictable dimensions and lighter files