Why Is My PNG File Still Large After Compression? (Fix Guide)
By admin · Jun 4, 2026
You've run your PNG through a compression tool and the file is still large — or barely smaller than the original. What went wrong? There are several common reasons PNG compression underperforms, and each has a specific fix. This guide covers all of them.
Reason 1: The Image Is Already Compressed
Problem: If you're compressing an image that's already been through lossy compression (e.g., you downloaded a PNG that was already compressed, or you're re-compressing a previously compressed file), the compression algorithm has little remaining data to reduce.
Fix: Always compress from the original source file — the one exported directly from Photoshop, Figma, Lightroom, or Canva. Never compress an already-compressed file.
Reason 2: The Image Has Very High Color Complexity
Problem: PNG lossy compression works by reducing the number of colors in an image. If your PNG is a complex photograph with millions of subtly different colors (especially skin tones, blue skies, or bokeh backgrounds), there's limited potential for color reduction.
Fix: For photographs, consider converting to JPG or WebP instead. These formats use different compression algorithms optimized for photographic content and can achieve smaller files with better quality for photos.
| Image Type | Expected Compression | If Poor: Try Instead |
|---|---|---|
| Logo / icon | 75–85% | — |
| Screenshot | 70–80% | — |
| Infographic | 70–80% | — |
| Complex photo | 40–65% | Convert to JPG or WebP |
| Gradient-heavy image | 50–70% | Convert to JPG |
Reason 3: The Image Is Too Large (Dimensions)
Problem: You're compressing a 6000×4000 px image — even at 80% compression, a 50 MB source file might only compress to 12 MB, which may still be "too large" for your use case.
Fix: Resize the image first, then compress. For web use, 1200–2000 px wide is almost always sufficient. Resize in Photoshop, Preview (Mac), or Paint (Windows) before compressing.
Example: A 6000×4000 px photo at 20 MB → resize to 1200×800 → compress = final size 250 KB (99% reduction).
Reason 4: You're Using Lossless Compression Only
Problem: Some compression tools (like OptiPNG, ImageOptim default settings, or Photoshop's "Save for Web" at 0% reduction) only apply lossless compression. Lossless typically achieves 5–25% reduction, not the 70–80% that lossy compression achieves.
Fix: Use a tool with lossy compression. compresspngfile.com uses pngquant lossy compression, which achieves 70–80% reduction. If your current tool only does lossless, switch tools.
Reason 5: The PNG Contains Embedded Metadata That Wasn't Stripped
Problem: PNG files can contain large color profiles (ICC profiles), EXIF data, thumbnail previews, and other metadata. A color profile alone can add 500 KB – 2 MB to a PNG file.
Fix: Use a compression tool that strips metadata. compresspngfile.com removes all unnecessary metadata during compression. Alternatively, in Photoshop: File > Export As > uncheck "Metadata" before exporting.
Reason 6: The Image Has a Huge Canvas with Transparent Areas
Problem: Some design tools export PNG files with large amounts of transparent padding around the actual content — creating a 3000×3000 px canvas for a logo that's actually 400×200 px. All those transparent pixels still take up file space.
Fix: Crop/trim the canvas to the actual content size before compressing.
- Photoshop: Image > Trim > Transparent Pixels
- GIMP: Image > Autocrop Image
- Figma: Make sure your export frame matches your content bounds
Reason 7: The File Size Is Already "Good" and You Need a Different Format
Problem: Sometimes, after compression, the file is still 1 MB because that's the best PNG can do for that image — and you need something under 200 KB.
Fix: Consider switching formats:
- WebP — 25–35% smaller than compressed PNG at similar quality. Full transparency support. All modern browsers.
- JPG — for photographs without transparency. Usually 50–80% smaller than PNG for photographic content.
- SVG — for simple logos and icons. Typically 10–50 KB, infinitely scalable.
Troubleshooting Checklist
| Symptom | Most Likely Cause | Fix |
|---|---|---|
| Less than 20% reduction | Already compressed or lossless tool | Use compresspngfile.com (lossy) |
| Still over 2 MB after compression | Too large dimensions | Resize first, then compress |
| File barely changed size | Already optimized or re-compressing | Start from original source file |
| Good compression but still too big | Wrong format for content type | Convert to JPG or WebP |
| Quality looks bad after compression | Too aggressive compression settings | Use higher quality setting |
Conclusion
If your PNG is still large after compression, the fix is usually one of these: start from the original source file, resize the dimensions first, use lossy compression (compresspngfile.com), strip metadata, or consider a different format like WebP for photographic content. In most cases, compresspngfile.com with a properly-sized source PNG will achieve 70–80% reduction.