What the quality setting changes
The quality setting affects how much visual detail the compressor tries to preserve.
At higher quality:
- the image usually looks closer to the original;
- file size is usually larger;
- small details and gradients may be preserved better.
At lower quality:
- file size is usually smaller;
- artifacts may become visible;
- text, edges, and smooth gradients may look worse;
- repeated saving can degrade the image further.
The effect depends on the image, format, and compression method.
How to choose a starting point
There is no single quality value that works for every image.
A practical approach:
- use higher quality for screenshots with text;
- use moderate quality for ordinary photos;
- avoid heavy compression for images with fine details;
- test a lower quality only when file size matters more;
- compare the output with the original before sharing.
If the image is for a form or website, choose the lowest setting that still looks acceptable for that use.
Compression vs resizing
Compression and resizing are different.
Compression changes how the image data is stored. Resizing changes the image dimensions.
If an image is too large because it is 4000 pixels wide, resizing may help more than compression alone. If the dimensions are already correct but the file is still too large, compression may be the better next step.
Often, the best workflow is:
1. resize to the dimensions you need; 2. compress carefully; 3. review the result.
For resizing, use Resize Image. For compression, use Compress Image.
Format differences
Image formats do not all use quality settings in the same way.
In general:
- JPEG is common for photos and uses lossy compression;
- PNG is useful for transparency and sharp graphics, but may stay large;
- WebP often gives strong compression in modern browsers;
- screenshots with text need more careful settings than simple photos.
Do not assume the same quality number means the same result across formats.
For more image workflows, see Utilio image tools.
Review before sharing
Before using the compressed image, check:
- the file size;
- visible artifacts;
- text readability;
- color changes;
- transparency if needed;
- metadata if privacy matters;
- whether the platform accepts the format.
Compression can make sharing easier, but the final check should be visual.
For broader privacy context, see Browser tools vs upload-based tools and Privacy Policy.
Common questions
What does image quality mean?
It describes how much visual detail the output tries to preserve during compression. Higher quality usually means a larger file. Lower quality usually means a smaller file with more visible loss.
Is 80 quality enough?
It can be a reasonable starting point for many photos, but it is not universal. Screenshots, graphics, and detailed images may need a higher setting.
Does lower quality always look worse?
Usually it increases the chance of visible artifacts, but some images tolerate compression better than others. Always compare the result with the original.
Which format compresses best?
It depends on the image and where it will be used. JPEG is common for photos, PNG is useful for transparency, and WebP often compresses well in modern browsers.
Should I compress or resize first?
If the image dimensions are larger than needed, resize first. Then compress the resized image and review the result.