What does image quality mean?
JPG and WebP are "lossy" formats: they throw away detail your eyes are unlikely to notice in order to make files smaller. The quality setting, from 0 to 1, controls how much is thrown away. At 0.9 the difference is almost invisible. Around 0.7 to 0.8 is the sweet spot for websites. Below 0.5, blocky artefacts appear, especially around text and sharp edges.
Compress to a target size
Many forms (job sites, visa and university portals) accept images up to a fixed size such as 100 KB or 2 MB. Type the limit in KB and the tool binary-searches the quality to get as close as possible underneath it. If it can't reach the target even at low quality, reduce the dimensions with the image resizer first, because fewer pixels always means a smaller file.
PNG is lossless, so it has no quality setting. Convert it to JPG (for photos) or WebP (for graphics) to shrink it. Everything is processed in your browser.
Frequently asked questions
How do I compress an image to 100 KB?
Enter 100 in the target size box. If it cannot get under 100 KB, resize the image to fewer pixels first.
What JPG quality is best?
0.75 to 0.85 gives small files with little visible loss.
How to use the Image Quality Changer & Compressor
- Choose or drop a JPG, PNG or WebP image.
- Adjust the settings and preview the result.
- Download the finished image to your device.
- Pick the right format using the table below.
Why use this Image Quality Changer & Compressor
100% in your browser
Nothing you enter is uploaded or stored.
Instant results
Updates as you type, no waiting.
Mobile friendly
Works on phones, tablets and desktops.
Light & dark mode
Follows your mfaysal.com theme.
Free, no account
No sign-up, no limits, no watermark.
Explained
Formulas, tables and sources on the page.
Image Quality Changer & Compressor: chart and reference data
Source: exact arithmetic; this is why very large photos can be slow on phones
| Format | Compression | Transparency | Best for |
|---|---|---|---|
| JPEG | Lossy | No | Photos, smallest files |
| PNG | Lossless | Yes | Cut-outs, logos, screenshots |
| WebP | Lossy or lossless | Yes | Websites (supported by all modern browsers) |
Image Quality Changer & Compressor compared with the alternatives
| Feature | This tool | Desktop editor | Upload-based website |
|---|---|---|---|
| Privacy | Stays on device | Stays on device | Uploaded to a server |
| Cost | Free | Often paid | Free tier with limits |
| Install needed | No | Yes | No |
| Watermark | None | None | Sometimes |
Who uses it in the UK
- Product photos for Etsy, eBay, Vinted or Shopify
- Profile pictures and CV photos
- Shrinking images for websites and email
- Social media posts and thumbnails
More questions
Are my images uploaded anywhere?
No. The image is decoded and processed in your browser with the HTML5 Canvas API (and WebAssembly where AI is used). It never leaves your device.
Why is a big photo slow on my phone?
Editing needs the full uncompressed image in memory. A 48-megapixel photo needs about 186 MB as RGBA, so phones may slow down. Resize it first if needed.
Will I lose quality?
PNG output is lossless. JPEG and WebP use lossy compression, so pick a high quality setting (around 85–92%) for photos you plan to print.
Is there a watermark?
No. Downloads are clean and free to use, including commercially for your own images.
✨ New: Remove the background from any image free – private, in your browser, transparent PNG.
Related free tools
Note: This free tool runs entirely in your browser. No data is sent or stored. Results are for information only.