Change Image Quality and Compression Tool
Change Image Quality and Compress JPEG, WebP, or PNG images with a live quality slider and file-size savings display. Free - no watermarks.
Re-encode any image as JPEG, WebP, or PNG with a live quality slider. The stats line shows the source size and the output size side by side, plus the percentage saved, so you can dial in the right trade-off.
How to Use Change Image Quality and Compression Tool
- Upload an image. Drop a JPG, PNG, WebP, or GIF onto the box, or click to pick one. The source stays in your browser - no upload.
- Pick an output format. JPEG is the go-to for photos. WebP is 25-35% smaller than JPEG at the same visual quality and is now supported everywhere. PNG is lossless - the quality slider is disabled when you pick it.
- Drag the quality slider. The live readout next to the label shows your current setting. 85% is a good default for JPEG and WebP; 70-80% is usually the sweet spot for thumbnails; 90%+ for hero images.
- Pick a JPEG background if relevant. When the source has transparency (PNG with alpha) and you convert to JPEG, those transparent pixels get filled with the colour you picked (white by default).
- Click Apply or press Ctrl/Cmd+Enter. The preview re-renders live as you drag the slider (100ms throttle) so you can see the trade-off in real time.
- Read the stats line. Source bytes vs output bytes side by side, with a savings percentage. Negative savings (output larger than source) can happen if you pick a very high quality or if the source was already heavily compressed.
- Copy or download. Copy places the image blob on your clipboard (Chrome/Edge/Safari over HTTPS). Download saves the file with the quality baked into the filename for easy A/B comparison.
Frequently Asked Questions
What does the quality percentage mean?
It’s the JPEG or WebP encoder’s quality parameter – 100% means “minimum compression, largest file, best fidelity”, lower values allow the encoder to discard more detail in exchange for smaller files. Most web images use 75-85% as a good balance.
Will reducing quality make my image look bad?
Above 70% the loss is typically invisible on photos. Below 50% you start to see blockiness on smooth gradients and ringing around sharp edges. The live preview helps you find the threshold for your specific image.
How much can I reduce file size?
Dropping a 100% JPEG to 85% typically cuts 50-70% of the bytes with no visible loss. At 50% you can often cut 80-90%. WebP at the same visual quality is usually 25-35% smaller than the JPEG equivalent.
What does WebP give me over JPEG?
WebP uses a more modern codec (similar to VP8/VP9 video) and supports both lossy and lossless compression, plus transparency. For photographic content it’s typically 25-35% smaller than JPEG at the same visual quality. All modern browsers, iOS/Android, and major image editors support it.
Why is the quality slider disabled in PNG mode?
PNG is a lossless codec – there is no “quality” dial in the JPEG sense. The tool still round-trips the image through a canvas so the output is a canonical PNG, which can still shrink oversized source PNGs by re-encoding.
What quality should I use for web images?
75-85% is the sweet spot for body content. Hero images and product shots benefit from 85-90%. Thumbnails can drop to 60-70% without most users noticing. If you need an exact byte budget, adjust until the stats line shows the savings you need.
Is my image uploaded to a server?
No. All compression runs in your browser with the HTML5 Canvas encoder. No network request touches your file, and the source is loaded only once into a local object URL.
Can I increase image quality beyond the original?
No. Re-encoding at 100% preserves what is already there but cannot add detail that was lost at an earlier save. If the original was saved at 70%, the highest effective quality you can recover is 70%.
Is this tool free to use?
Yes – completely free, no watermarks, no registration, no file-size caps, no usage caps.
Why is my “savings” sometimes negative?
When the source was a heavily compressed JPEG and you re-encode at 100% JPEG – or when you go from compressed JPEG to lossless PNG – the output can be larger than the input. The stats line shows a negative savings percentage so you notice before downloading.