Image Quality Reducer: A Practical Guide
Use Image Quality Reducer to re-encode images at a chosen quality level. It is useful when a smaller lossy file is more important than retaining every fine detail. Keep the original so you can try a different setting without accumulating compression loss.
How to Use Image Quality Reducer
- Select the images.
- Choose an output format.
- Adjust Quality and run Reduce quality.
- Inspect previews, sizes and downloaded files.
Quality Is an Encoding Setting
The percentage slider controls the encoder, not an objective percentage of visual quality. The same setting can produce different sizes for a photograph, screenshot and flat-color graphic.
PNG output is lossless, so a JPEG-style quality adjustment does not reduce its detail in the same way. Choose a suitable lossy format when that tradeoff is intended.
Worked Example
For a photo used as a small thumbnail, compare a medium-quality encoding with the original. Fine texture may change without being noticeable at thumbnail size.
For a screenshot containing small letters, the same setting may create visible halos. Check the actual content rather than copying one setting everywhere.
Compare compression candidates: use the Image Compressor.
Change pixel dimensions: use the Image Resizer.
Checks and Common Mistakes
- Do not mistake quality for image dimensions.
- Check transparency when choosing JPEG.
- Retain an original source.
- Do not guarantee an exact target file size.
Frequently Asked Questions
Does a setting of 50 mean half the file size?
No. Content and format determine the result; quality is not a linear size percentage.
Can I restore detail afterward?
Re-encoding at higher quality cannot reconstruct detail already discarded.
Why use the compressor instead?
Image Compressor is useful for comparing smaller candidates, while this page focuses on an explicit quality tradeoff.
Related Tools for the Next Step
- Image Compressor: Compare compression candidates.
- Image Resizer: Change pixel dimensions.
- Image Converter: Choose another format.
- Image Dimensions Checker: Inspect the result’s properties.
Reference
Further reading: MDN image file types and formats.