Reduce image quality on purpose
Sometimes you need a smaller file, not a prettier one. Drag the slider and see exactly what each quality step costs.
- Runs in your browser
- Nothing is uploaded
- No sign-up
- Batch up to 20 images
Drag & drop your image here
or tap to browse · you can also paste from the clipboard
JPG · PNG · WebP · GIF · BMP · AVIF · SVG · up to 50 MB each · up to 20 files
Choose imagesBefore
After
Processed image will appear here.
How to use the image quality reducer
Upload an image and drag the quality slider down while watching the file size and preview update live. Stop at the last setting that still looks acceptable. Quality 100 to 90 often halves the file for no visible change; below 60 the damage becomes obvious.
- Load your imageAny format your browser can read.
- Drag the quality sliderThe preview and file size update as you move it.
- DownloadSave at the quality you settled on.
About this tool
Every lossy encoder exposes a quality parameter, and the relationship between that number and file size is strongly non-linear. Going from 100 to 90 often halves the file for almost no visible change; going from 50 to 40 saves very little but does visible damage.
This tool exposes that curve directly. Move the slider, watch both the preview and the byte count, and stop at the last setting that still looks acceptable to you.
What you get
- Fine-grained 1-100 quality control
- Live file size readout at every step
- JPG, WebP and PNG output (PNG maps quality to palette size)
- Optional resize for larger reductions
- Side-by-side original comparison
When to use the image quality reducer
Hitting a hard upload limit
When dimensions must stay the same but the file must shrink, quality is the only lever left.
Finding your own threshold
Everyone's tolerance differs by content. Watching the preview change as you drag teaches you where the line is for your images.
Comparing formats fairly
Set the same quality in JPG and WebP and compare the resulting sizes to see the codec difference on your actual content.
Deliberately degrading for previews
Low-quality placeholders that load instantly and are replaced by the full image are a standard progressive-loading technique.
The quality-to-size curve
| Quality drop | Typical size change | What you lose |
|---|---|---|
| 100 → 90 | −40 to −55% | Essentially nothing visible |
| 90 → 80 | −25 to −35% | Nothing visible in normal viewing |
| 80 → 70 | −15 to −20% | Slight softening of fine texture |
| 70 → 60 | −10 to −15% | Faint blocking in smooth gradients |
| 60 → 50 | −7 to −12% | Visible blocking; edges ring |
| 50 → 30 | −10 to −18% | Obvious degradation |
How it works
The relationship between quality and file size is steeply non-linear, and understanding the shape saves a lot of guesswork. Most of the size is carried by a small number of low-frequency coefficients that survive at any setting; the long tail of high-frequency detail is what the quality value decides to keep or discard. That tail is large in count but small in perceptual value, which is why the first ten points of reduction are nearly free and the last ten are ruinous.
Content changes where the useful stopping point sits. Busy textures (foliage, gravel, fabric) mask artefacts well and tolerate quality 70 comfortably. Smooth gradients such as skies, studio backdrops and skin show blocking early. Text and line art are worst of all: the ringing around sharp edges is visible even at quality 90.
Note that the quality number is encoder-specific. Quality 80 in your browser's JPEG encoder does not correspond to quality 80 in Photoshop or MozJPEG, and it certainly does not correspond to quality 80 in WebP. Judge by the preview and the byte count, not the number.
Common problems and how to fix them
- Lowering the quality barely shrinks the file
- The image is dominated by pixel count rather than encoding precision. Switch on "Also resize the image", because dimensions are the bigger lever.
- The preview looks fine but the download looks worse
- The preview is displayed smaller than the actual image. Open the downloaded file at 100% before deciding.
- I went too far and lost the original
- Lossy compression cannot be undone, and we never had a copy. Always keep originals, and press Reset before downloading if you are still experimenting.
- My screenshot looks terrible at quality 80
- Screenshots contain text and sharp edges, which JPEG handles badly at any setting. Use PNG or WebP.
Frequently asked questions
Why would I want lower quality on purpose?
Hard limits: email attachment caps, forum upload restrictions, government portals that reject anything over 200 KB, and bandwidth-constrained users. Quality is the knob you turn when dimensions must stay the same.
What does the quality number actually mean?
It controls the quantisation tables the encoder uses, which decide how coarsely the frequency information is rounded. It is not a percentage of anything, and the same number produces different results in different encoders.
At what point does it look bad?
For photographs, most people notice degradation below about 70 and find it objectionable below 50. Images with text, sharp lines or flat colour show damage far earlier, often by 85.
Can I undo quality reduction?
No. Lossy compression is irreversible. Always keep your original file.
Should I reduce quality or dimensions?
Reduce dimensions first if the image is bigger than it will ever be displayed, because that costs no visible quality at all. Reach for the quality slider once the dimensions are already right.
Can I reduce the quality of several images at once?
Yes. Drop up to 20 images, set the quality on the first one, then press "Process all images" and download everything as a ZIP.