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Luca Sammarco
Luca Sammarco

Posted on • Originally published at sammapix.com

Methodology

Image Compression Benchmark 2026: We Tested 10 Tools on 100 Real Images
By Luca Sammarco | April 2, 2026 | 18 min read
Tags: Performance, Tools


KEY RESULT

In a benchmark of 100 real-world images compressed through 10 online tools at 4 quality levels (4,000 total compressions), Squoosh achieved the best quality-to-size ratio with a SSIMULACRA 2 score of 78.4 at 72% file size reduction. TinyPNG delivered the best automatic compression at 68% reduction with zero configuration. ShortPixel achieved the highest raw reduction at 76%. Only SammaPix and Squoosh process images locally in the browser without uploading to servers. At quality 80%, all 10 tools scored above 65 on SSIMULACRA 2, meaning no visible quality loss for standard web use.


KEY TAKEAWAYS

  • Squoosh delivers the best quality-to-size ratio (SSIMULACRA 2: 78.4, reduction: 72%) but requires manual tuning per image.
  • TinyPNG is the most consistent automatic compressor (68% avg reduction, quality 72.1) with zero configuration needed.
  • ShortPixel achieves the highest file size reduction (76%) but is more aggressive, scoring lower on visual quality (75.8 at quality 90, dropping to 62.1 at quality 60).
  • Only 2 of 10 tools (SammaPix and Squoosh) process images in the browser. The other 8 upload your files to remote servers.
  • At quality 80%, every tool scored above 65 on SSIMULACRA 2, meaning virtually no visible quality loss for web use.

INTRODUCTION

Here's the thing about image compression tools: they all claim the same thing. "Best quality." "Smallest files." "No visible difference." I got tired of marketing copy, so I decided to test it myself. I took 100 real images, ran them through 10 different compression tools at 4 quality levels, and measured everything: file size reduction, perceptual quality using SSIMULACRA 2, processing speed, and whether each tool actually keeps your images private.

That's 4,000 total compressions. Every single one measured and logged. The raw data is available on GitHub (https://github.com/samma1997/compression-benchmark-2026).

I'll be honest: some of these results genuinely surprised me. The tool with the highest file size reduction isn't the one with the best quality. The fastest tool isn't the most convenient. And most tools upload your images to servers even when they don't need to. Let's get into the data.


METHODOLOGY

I selected 100 images split evenly across five categories: photos (20), UI screenshots (20), e-commerce products (20), illustrations (20), and text-heavy images (20). All source images were high-quality JPEGs and PNGs ranging from 1 MB to 12 MB, sourced from real production environments, stock libraries, and my own travel photography.

Each image was compressed through all 10 tools at 4 quality levels: 90%, 80%, 70%, and 60%. For tools that don't expose a quality slider (like TinyPNG), I used their default automatic compression. For Squoosh, I matched quality levels using MozJPEG's quality parameter.

Every compressed output was scored on four metrics:

  • File size reduction (%): How much smaller the compressed file is compared to the original. Higher is better. Measured as (original - compressed) / original * 100.
  • SSIMULACRA 2 score: A perceptual quality metric from Cloudinary that correlates with how humans perceive image quality. Scale: 30 = low quality, 50 = medium, 70 = high, 90+ = nearly lossless. We used the reference implementation from the libjxl project.
  • Processing speed: Total time from upload/drop to download availability, measured in seconds. Tested on a MacBook Pro M3 with 100 Mbps connection. Browser-based tools were tested in Chrome 124.
  • Privacy: Whether the tool processes images locally (browser-based, no upload) or sends files to remote servers. Verified using Chrome DevTools Network tab.

For tools with automatic-only compression (TinyPNG, iLoveIMG, CompressJPEG), I recorded their single output and used it in the "auto" column of our results. Their data points appear at whichever quality level most closely matches their automatic output.


THE 10 TOOLS WE TESTED

I picked these 10 based on search volume, industry reputation, and coverage in existing comparison articles. Every tool was tested using its free tier or web interface.

Tool Type Processing Quality control Free limit
SammaPix Web app Browser (local) Quality slider Unlimited
TinyPNG Web app Server upload Automatic only 20 images, 5 MB each
Squoosh Web app Browser (local) Full manual control Unlimited, 1 at a time
ShortPixel Web app + API Server upload Lossy / Glossy / Lossless 50 images/month
Compressor.io Web app Server upload Lossy / Lossless toggle 10 MB, 1 at a time
Kraken.io Web app + API Server upload Lossy / Lossless + expert 1 MB limit (free)
iLoveIMG Web app Server upload Automatic only Unlimited (with ads)
Optimizilla Web app Server upload Quality slider per image 20 images at a time
ImageOptim Web app + Mac Server upload Quality preset Unlimited (web)
CompressJPEG Web app Server upload Quality slider 20 images at a time

OVERALL RESULTS (Quality 80%)

Rank Tool Size reduction SSIMULACRA 2 Speed (avg) Privacy
1 Squoosh 72% 78.4 2.1s Local
2 ShortPixel 76% 73.6 3.8s Upload
3 SammaPix 71% 74.2 1.4s Local
4 TinyPNG 68% 72.1 4.2s Upload
5 Kraken.io 69% 71.8 5.1s Upload
6 Compressor.io 66% 73.9 3.6s Upload
7 Optimizilla 65% 71.5 4.7s Upload
8 ImageOptim 62% 76.3 3.2s Upload
9 iLoveIMG 64% 69.4 4.9s Upload
10 CompressJPEG 61% 68.7 5.4s Upload

The ranking is based on a weighted composite: 40% quality (SSIMULACRA 2), 35% size reduction, 15% speed, 10% privacy.

ImageOptim has the second-highest quality score (76.3) but the lowest file size reduction (62%). That's because ImageOptim is conservative by design. It prioritizes quality preservation over aggressive compression.


RESULTS BY IMAGE CATEGORY

PHOTOS (20 images): landscapes, portraits, street photography

Tool Reduction SSIMULACRA 2
Squoosh 74% 80.2
ShortPixel 79% 74.1
SammaPix 73% 75.8
TinyPNG 71% 73.4
ImageOptim 64% 78.1

Photos compress the best across the board. ShortPixel's 79% reduction on photos was the highest single-category number in the entire benchmark. But look at the quality gap: Squoosh scores 80.2 vs ShortPixel's 74.1. That 6-point difference is noticeable when you zoom in.

UI SCREENSHOTS (20 images): dashboards, app interfaces, web pages

Tool Reduction SSIMULACRA 2
Squoosh 68% 76.9
SammaPix 66% 73.1
TinyPNG 63% 71.8
ShortPixel 72% 70.4
Compressor.io 61% 72.6

Screenshots are harder to compress than photos. JPEG compression introduces visible ringing artifacts around text at aggressive quality levels. ShortPixel's aggressive approach shows visible artifacts around UI text in 8 out of 20 images.

E-COMMERCE PRODUCTS (20 images): product photos on white backgrounds

Tool Reduction SSIMULACRA 2
TinyPNG 72% 74.3
Squoosh 75% 79.1
ShortPixel 78% 75.2
SammaPix 74% 75.6
Kraken.io 71% 73.5

E-commerce images compress really well. Large white backgrounds compress down to almost nothing. TinyPNG was surprisingly strong on product images, largely because its smart quantization algorithm excels on limited color palettes.

ILLUSTRATIONS (20 images): flat design, icons, vector-style graphics

Tool Reduction SSIMULACRA 2
Squoosh 71% 78.8
SammaPix 69% 74.0
TinyPNG 66% 71.4
ShortPixel 74% 72.8
Compressor.io 65% 74.2

Illustrations revealed the biggest quality differences between tools. Flat design graphics with sharp color boundaries are tricky for lossy compression. Compressor.io punched above its weight here at 74.2.

TEXT-HEAVY IMAGES (20 images): infographics, slides, documents

Tool Reduction SSIMULACRA 2
Squoosh 69% 77.1
ImageOptim 58% 76.8
SammaPix 67% 72.4
TinyPNG 64% 70.2
ShortPixel 73% 68.7

Text-heavy images are the acid test for compression quality. Small text is extremely sensitive to JPEG artifacts. ShortPixel's 73% reduction comes at the cost of a quality score of just 68.7, with small text starting to look fuzzy.


QUALITY LEVEL COMPARISON

Tool Q90 Red% Q90 SS2 Q80 Red% Q80 SS2 Q70 Red% Q70 SS2 Q60 Red% Q60 SS2
Squoosh 58% 84.2 72% 78.4 79% 71.6 84% 64.8
ShortPixel 62% 75.8 76% 73.6 82% 66.2 87% 62.1
SammaPix 56% 82.6 71% 74.2 78% 67.1 83% 61.4
Kraken.io 54% 79.4 69% 71.8 77% 65.3 82% 59.7
Optimizilla 51% 78.9 65% 71.5 74% 64.8 80% 58.2

The sweet spot is quality 80%. Every tool scored above 65 on SSIMULACRA 2, meaning no visible quality loss for typical web viewing. Going from 80% to 70% quality gives you another 7-8 percentage points of file size reduction, but quality drops below 70 for most tools. That's the cliff.

Key insight: Squoosh at quality 70% outperforms ShortPixel at quality 80% on visual quality (71.6 vs 73.6) while achieving a higher file size reduction (79% vs 76%). The encoder matters more than the quality number.


SPEED BENCHMARK

Rank Tool Single image 10 images (batch) Why
1 SammaPix 1.4s 8.2s No upload, local WASM
2 Squoosh 2.1s N/A (single only) No upload, local WASM
3 ImageOptim 3.2s 18.4s Fast server, small files
4 Compressor.io 3.6s N/A (single only) Fast processing
5 ShortPixel 3.8s 22.1s Server queue time
6 TinyPNG 4.2s 14.8s Parallel processing
7 Optimizilla 4.7s 26.3s Sequential processing
8 iLoveIMG 4.9s 19.7s Ad-heavy page slows UI
9 Kraken.io 5.1s 24.8s 1 MB limit slows workflow
10 CompressJPEG 5.4s 28.1s Slow server response

Browser-based tools dominate speed because they skip the upload/download cycle entirely. Squoosh is the only browser-based tool that doesn't support batch processing.


PRIVACY AND DATA HANDLING

Tool Upload required? Data retention Privacy score
SammaPix No upload Zero. Nothing leaves browser. 10/10
Squoosh No upload Zero. Nothing leaves browser. 10/10
TinyPNG Yes Deleted after compression 7/10
ShortPixel Yes Deleted after 1 hour 7/10
Compressor.io Yes Deleted after processing 6/10
Kraken.io Yes Unclear retention policy 5/10
ImageOptim Yes (web) Deleted after processing 6/10
iLoveIMG Yes Deleted after 2 hours 6/10
Optimizilla Yes Deleted after 1 hour 6/10
CompressJPEG Yes Unclear retention policy 4/10

Only 2 out of 10 tools keep your images private. SammaPix and Squoosh both use WebAssembly to run compression algorithms entirely in the browser. Verified using Chrome DevTools Network tab: zero outbound requests when compressing.


FORMAT SUPPORT MATRIX

Tool JPEG PNG WebP AVIF GIF SVG
SammaPix Yes Yes Yes No Yes No
TinyPNG Yes Yes Yes Yes No No
Squoosh Yes Yes Yes Yes Yes No
ShortPixel Yes Yes Yes Yes Yes No
Compressor.io Yes Yes Yes No Yes Yes
Kraken.io Yes Yes Yes Yes Yes Yes
iLoveIMG Yes Yes No No Yes Yes
Optimizilla Yes Yes No No Yes No
ImageOptim Yes Yes No No Yes No
CompressJPEG Yes Yes No No Yes No

7 KEY FINDINGS

  1. Quality 80% is the universal sweet spot
    At Q80, every tool scored above 65 on SSIMULACRA 2. Average reduction was 67%. Going from Q80 to Q70 gives 7.8% more reduction but drops quality by 6.1 points.

  2. MozJPEG-based tools consistently outperform others
    Squoosh and SammaPix both use MozJPEG via WebAssembly, scoring 78.4 and 74.2 respectively. MozJPEG produces higher quality output per byte than standard libjpeg.

  3. Higher compression does not always mean lower quality
    Squoosh at Q70 achieved 79% reduction with SS2 of 71.6. ShortPixel at Q80 achieved 76% reduction with SS2 of 73.6. The encoder matters more than the quality number.

  4. Text-heavy images need special handling
    Every tool performed worst on text-heavy images. Average SS2 dropped 4.3 points vs photos. Keep quality at 85%+ for images with readable text, or use PNG.

  5. Browser-based tools are 2-4x faster than server-based ones
    SammaPix averaged 1.4s per image vs 4.5s average for server-based tools. The difference isn't processing speed, it's upload/download overhead.

  6. "Automatic" compression quality varies wildly
    TinyPNG targets Q75-Q80 equivalent (smart). iLoveIMG was more aggressive, closer to Q65-Q70 (often too aggressive). TinyPNG's auto algorithm is significantly better calibrated.

  7. Most "free" tools have frustrating limits
    TinyPNG: 5 MB, 20 images. Kraken.io: 1 MB (useless for modern photos). ShortPixel: 50/month. Squoosh: 1 image at a time. Only SammaPix and iLoveIMG are truly unlimited free.


WHICH TOOL SHOULD YOU USE?

Best overall quality: Squoosh

Best quality-to-size ratio. Full manual control. Use for important hero images. Skip when you need batch processing.

Best for batch processing: SammaPix

Local processing, no upload, supports batch with ZIP download. Scored 74.2 on quality. Skip when you need AVIF output.

Best "set it and forget it": TinyPNG

Zero configuration. Best-calibrated automatic algorithm. Great API. Skip when images are over 5 MB or you care about privacy.

Best for maximum file size reduction: ShortPixel

76% average reduction (highest in test). WordPress plugin integration. Skip for text-heavy images or when quality is paramount.

Best for WordPress: ShortPixel or TinyPNG

Both have excellent WordPress plugins. ShortPixel gives higher reduction, TinyPNG gives better quality.

Best for sensitive/confidential images: SammaPix or Squoosh

Only options that process entirely in the browser. Zero data leaves your device.


HOW SAMMAPIX COMPARES

Transparent breakdown of SammaPix in this benchmark:

  • Quality (74.2): Third place, behind Squoosh (78.4) and ImageOptim (76.3).
  • File size reduction (71%): Also third, behind ShortPixel (76%) and Squoosh (72%).
  • Speed (1.4s): First place. No upload means no waiting.
  • Privacy (10/10): Tied for first with Squoosh.
  • Batch support: Squoosh doesn't do batch. SammaPix does.

SammaPix isn't the best at any single metric except speed. But it's the only tool that combines good quality, local processing, batch support, and zero cost with no file size limits.


FAQ

Q: What is the best image compression tool in 2026?

A: It depends on your priority. Squoosh delivers the best quality (SSIMULACRA 2: 78.4). TinyPNG is the most convenient (zero config). SammaPix is best for privacy and batch. ShortPixel achieves the highest compression (76%).

Q: Is TinyPNG still worth using in 2026?

A: Yes. TinyPNG scored 72.1 on SSIMULACRA 2 with 68% reduction, the best automatic-only compressor. Main drawbacks: 5 MB cap, 20-image limit, server upload.

Q: Which tool preserves the most visual quality?

A: Squoosh (SSIMULACRA 2: 78.4). ImageOptim is second (76.3) but achieves lower reduction (62% vs 72%).

Q: What is SSIMULACRA 2 and why does it matter?

A: A perceptual quality metric by Cloudinary. Unlike PSNR, it correlates closely with human perception. Scores above 70 = high quality. Below 50 = noticeable degradation. Standard in JPEG XL reference implementation.

Q: Which tools process images locally?

A: Only SammaPix and Squoosh. Both use WebAssembly. Verified via Chrome DevTools: zero outbound requests.

Q: How much can I compress without visible quality loss?

A: At Q80%, all 10 tools scored above 65 on SSIMULACRA 2, meaning no visible loss. Average reduction at Q80 was 67%. Below Q70%, artifacts become noticeable.


Raw data: https://github.com/samma1997/compression-benchmark-2026


Originally published at sammapix.com

Try it free: SammaPix — 27 browser-based image tools. Compress, resize, convert, remove background, and more. Everything runs in your browser, nothing uploaded.

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