Image Resolution Explained: Pixels, PPI, DPI, and Quality
Understand the difference between image dimensions, PPI, and DPI, and learn how to preserve quality during conversion.
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Quick Summary
Understand the difference between image dimensions, PPI, and DPI, and learn how to preserve quality during conversion.
- Pixel dimensions
- PPI and DPI are not the same
- Why conversion cannot restore missing detail
- How to preserve quality
Image quality is influenced by more than the file extension. Pixel dimensions, compression level, source quality, and the intended display or print size all matter.
Pixel dimensions
An image that is 1920 × 1080 contains 1920 pixels across and 1080 pixels vertically. These dimensions are usually more important than PPI when the image is displayed on a website or screen.
PPI and DPI are not the same
PPI means pixels per inch and describes pixel density. DPI means dots per inch and is commonly associated with printing. People often use the terms interchangeably, but they refer to different parts of the workflow.
Why conversion cannot restore missing detail
Changing a small JPG into PNG does not recreate detail that was already lost. Conversion can change compatibility or compression characteristics, but it cannot recover information that is absent from the source.
How to preserve quality
- Start with the highest-quality source available.
- Avoid repeated lossy conversions.
- Keep the original dimensions unless resizing is necessary.
- Compare the converted output at normal viewing size and at 100% zoom.
Use our JPG to PNG converter or PNG to JPG converter when you need a different format, and always inspect the final result.
