How to Compress Images Without Losing Quality
Kordu Team · 2026-03-31
Key Takeaways
- Quality 75-85 produces files 60-80% smaller than the original with no visible difference in most photographs.
- Images account for 50-70% of a web page's total weight. Compressing them is the single biggest performance win.
- Resize first, compress second. Scaling a 4000x3000 photo to 1200x900 before compressing can cut size from 8 MB to under 100 KB.
- Our compressor runs in your browser -- your photos never leave your device.
Compress Your Images
Drop images below to compress them. Adjust the quality slider to find the balance between file size and visual fidelity. Everything runs in your browser.
Click to upload or drag and drop
PNG, JPG, JPEG, WEBP up to 50MB
For most photographs, quality 75-85 cuts 60-80% of the file size with no perceptible difference.
Why This Matters
A single uncompressed photo from a modern camera weighs 5-15 MB. A dozen product images on one page means you are asking visitors to download 100+ MB.
Google’s Core Web Vitals penalise slow pages. Largest Contentful Paint (LCP) — the metric for when main content becomes visible — is dominated by hero images and product photos. Compressing them is the fastest, lowest-effort improvement you can make to your LCP score, your hosting bill, and your mobile user experience.
Lossy vs Lossless: Choose the Right One
Lossy compression
Discards data the human eye barely notices. In a landscape photo, millions of subtle colour gradations in the sky get represented with fewer unique values. Looks identical, dramatically smaller file.
JPEG has done this since 1992. WebP and AVIF are better at deciding what to discard — same visual quality, smaller files.
The catch: once data is gone, it is gone. Compressing a JPEG at quality 20, saving it, and re-compressing loses more each time. Always keep originals.
Lossless compression
Reduces file size without discarding anything. The decompressed output is bit-for-bit identical to the input. PNG and WebP lossless both work this way.
Essential for images where every pixel matters: logos, icons, screenshots with text, technical diagrams. But lossless files are significantly larger than lossy for photographic content.
Do not use PNG for photographs
PNG is lossless, which makes it excellent for graphics with sharp edges and flat colours. For photographs, PNG produces files 5-10x larger than JPEG at equivalent visual quality. Use JPEG or WebP for photos. Reserve PNG for graphics, screenshots, and transparency.
Format Comparison: Real Numbers
| Feature | JPEG | PNG | WebP | AVIF |
|---|---|---|---|---|
| Compression type | Lossy | Lossless | Both | Both |
| Transparency | No | Yes | Yes | Yes |
| Animation | No | No (APNG exists) | Yes | Yes |
| Typical photo size (1 MP) | 80-150 KB | 500-1500 KB | 50-120 KB | 30-90 KB |
| Browser support | Universal | Universal | 97%+ | 93%+ |
| Encoding speed | Fast | Fast | Moderate | Slow |
| Best for | Photos, thumbnails | Logos, screenshots, icons | General web use | Maximum compression |
JPEG — safe default for photos when you need universal compatibility.
PNG — correct choice for transparency or pixel-perfect reproduction: logos, UI screenshots, diagrams, icons.
WebP — best balance for modern web use. Both lossy and lossless, transparency, animation, 25-35% smaller than equivalent JPEGs, 97%+ browser support. Should be your default format in 2026. See our WebP conversion guide.
AVIF — smallest files (40-50% smaller than JPEG at same quality), but slow to encode and 93% browser support still has gaps.
Quality Settings by Image Type
Photographs (product shots, hero images, blog posts)
Lossy at quality 75-85. Hero images at full viewport width: lean towards 80-85. Thumbnails at 200-300px wide: 70-75 is fine because small display size hides artefacts.
Screenshots and UI images
Use PNG. Lossy compression creates visible artefacts around text edges. If file size matters, convert to WebP lossless — 20-30% smaller than PNG with zero quality loss.
Logos and icons
SVG wherever possible. For raster logos, PNG or WebP lossless. Never JPEG for logos — compression artefacts around sharp edges and flat colours are immediately visible.
Responsive images
Do not serve a 3000px-wide image to a phone with a 400px viewport. A 2x retina version of a 600px content image only needs to be 1200px wide. Use our Image Resizer to batch-resize before compression.
Resize first, compress second
Resizing a 4000x3000 photo to 1200x900 before compressing at quality 80 can cut file size from 8 MB to under 100 KB — a 98% reduction. Compression alone might get you to 1-2 MB. Always resize first.
The Compression Workflow
- Start with your highest-quality source. Never compress an already-compressed image. Artefacts compound with each pass.
- Crop and resize to the maximum display size. This is the single biggest file size reduction.
- Choose your format. WebP for general web, JPEG for maximum compatibility, PNG for transparency and text-heavy images.
- Compress at quality 75-85 for lossy. Lossless for graphics.
- Compare. Open at 100% zoom next to the original. If you cannot tell the difference, you are done. If you can, bump quality up 5 points and try again.
- Serve with caching headers. Set
Cache-Controlwith a longmax-ageso browsers cache images instead of re-downloading them.
Start Compressing
Our Image Compressor runs in your browser, supports batch processing, and lets you compare before-and-after side by side. For additional savings, convert to WebP format.