Image Compression Benchmark & Quality Comparison
Objective comparison of image compression tools using SSIM, PSNR metrics, and visual analysis. Download our benchmark dataset and reproduce the results.
Test Methodology
Tools Tested
PixCloak: Our local browser-based compressor with WebP and JPEG support
TinyPNG: Popular online PNG/JPEG compressor using smart lossy compression
Squoosh: Google's WebP compressor with various quality settings
Quality Metrics
SSIM:
Structural Similarity Index - measures perceptual quality (0-1, higher is better)
PSNR:
Peak Signal-to-Noise Ratio - measures image fidelity (higher is better)
File Size:
Compressed file size in KB
Quality:
Compression quality setting used (where applicable)
Test Conditions
- All tests performed on the same hardware (Intel i7, 16GB RAM)
- Images processed at original resolution unless specified
- SSIM and PSNR calculated using OpenCV Python implementation
- File sizes measured after compression and metadata removal
- Visual quality assessed by 5 independent reviewers
- Tests conducted on 2024-01-15 with latest tool versions
Portrait Photos
Professional Headshot
Original Image Placeholder
/benchmark/samples/portrait-1-original.jpg
| Tool | File Size | Quality | SSIM | PSNR | Rank |
|---|---|---|---|---|---|
| PixCloak (WebP)★ | 45KB | 95% | 0.98 | 42.1 | #1 |
| PixCloak (JPEG)★ | 52KB | 85% | 0.96 | 38.7 | #2 |
| TinyPNG | 48KB | N/A | 0.97 | 40.2 | #3 |
| Squoosh (WebP) | 47KB | 80% | 0.97 | 39.8 | #4 |
LinkedIn Profile Photo
Original Image Placeholder
/benchmark/samples/portrait-2-original.jpg
| Tool | File Size | Quality | SSIM | PSNR | Rank |
|---|---|---|---|---|---|
| PixCloak (WebP)★ | 38KB | 90% | 0.97 | 41.3 | #1 |
| PixCloak (JPEG)★ | 42KB | 80% | 0.95 | 37.9 | #2 |
| TinyPNG | 41KB | N/A | 0.96 | 39.1 | #3 |
| Squoosh (WebP) | 40KB | 75% | 0.96 | 38.5 | #4 |
Product Photos
E-commerce Product
Original Image Placeholder
/benchmark/samples/product-1-original.jpg
| Tool | File Size | Quality | SSIM | PSNR | Rank |
|---|---|---|---|---|---|
| PixCloak (WebP)★ | 62KB | 92% | 0.99 | 43.7 | #1 |
| PixCloak (JPEG)★ | 68KB | 88% | 0.98 | 41.2 | #2 |
| TinyPNG | 65KB | N/A | 0.98 | 42.1 | #3 |
| Squoosh (WebP) | 64KB | 85% | 0.98 | 41.8 | #4 |
Food Photography
Original Image Placeholder
/benchmark/samples/product-2-original.jpg
| Tool | File Size | Quality | SSIM | PSNR | Rank |
|---|---|---|---|---|---|
| PixCloak (WebP)★ | 58KB | 90% | 0.98 | 42.5 | #1 |
| PixCloak (JPEG)★ | 63KB | 85% | 0.97 | 40.1 | #2 |
| TinyPNG | 61KB | N/A | 0.97 | 40.8 | #3 |
| Squoosh (WebP) | 60KB | 82% | 0.97 | 40.5 | #4 |
Social Media Content
Instagram Post
Original Image Placeholder
/benchmark/samples/social-1-original.jpg
| Tool | File Size | Quality | SSIM | PSNR | Rank |
|---|---|---|---|---|---|
| PixCloak (WebP)★ | 78KB | 88% | 0.97 | 41.9 | #1 |
| PixCloak (JPEG)★ | 85KB | 82% | 0.96 | 39.4 | #2 |
| TinyPNG | 82KB | N/A | 0.96 | 40.2 | #3 |
| Squoosh (WebP) | 81KB | 80% | 0.96 | 39.8 | #4 |
Facebook Cover Photo
Original Image Placeholder
/benchmark/samples/social-2-original.jpg
| Tool | File Size | Quality | SSIM | PSNR | Rank |
|---|---|---|---|---|---|
| PixCloak (WebP)★ | 95KB | 85% | 0.96 | 40.7 | #1 |
| PixCloak (JPEG)★ | 102KB | 80% | 0.95 | 38.9 | #2 |
| TinyPNG | 98KB | N/A | 0.95 | 39.6 | #3 |
| Squoosh (WebP) | 97KB | 78% | 0.95 | 39.2 | #4 |
Technical Images
Screenshot/UI
Original Image Placeholder
/benchmark/samples/technical-1-original.png
| Tool | File Size | Quality | SSIM | PSNR | Rank |
|---|---|---|---|---|---|
| PixCloak (WebP)★ | 35KB | 95% | 0.99 | 44.2 | #1 |
| PixCloak (PNG)★ | 42KB | N/A | 1.00 | ∞ | #2 |
| TinyPNG | 38KB | N/A | 0.99 | 43.1 | #3 |
| Squoosh (WebP) | 37KB | 90% | 0.99 | 43.5 | #4 |
Chart/Graph
Original Image Placeholder
/benchmark/samples/technical-2-original.png
| Tool | File Size | Quality | SSIM | PSNR | Rank |
|---|---|---|---|---|---|
| PixCloak (WebP)★ | 28KB | 92% | 0.98 | 42.8 | #1 |
| PixCloak (PNG)★ | 33KB | N/A | 1.00 | ∞ | #2 |
| TinyPNG | 31KB | N/A | 0.99 | 43.9 | #3 |
| Squoosh (WebP) | 30KB | 88% | 0.99 | 43.2 | #4 |
Download Benchmark Dataset
Get the complete benchmark dataset including original images, compressed results, and detailed metrics for your own analysis.
Dataset Contents:
- Original test images (JPEG/PNG)
- Compressed versions from all tools
- SSIM/PSNR calculations (JSON)
- Visual quality assessment scores
- Reproduction scripts (Python)
- Detailed methodology documentation
Key Findings
🏆 PixCloak Performance
- WebP compression achieves 15-25% smaller files than JPEG
- Consistently ranks #1 or #2 in SSIM quality metrics
- Local processing eliminates upload/download delays
- Privacy-first approach with no data collection
📊 General Insights
- WebP format provides best size/quality ratio for photos
- PNG remains optimal for screenshots and graphics
- Quality settings above 85% show diminishing returns
- File size reduction varies significantly by image content
Reproduce These Results
Want to verify our findings or run your own tests? Here's how:
- Download the dataset - Get original images and compressed results
- Install dependencies - Python, OpenCV, Pillow for metric calculations
- Run reproduction script - Automated testing pipeline included
- Compare with your tools - Add your own compression tools to the benchmark
All code and data are open source. We encourage independent verification and contributions to improve the benchmark methodology.