I measured DigImg vs TinyPNG vs ShortPixel on the same images (bytes + SSIM)
A smaller image file is useful. A smaller file that visibly damages a logo, screenshot, or photo is not always a win. So instead of comparing marketing claims, I ran the same four source images through DigImg, TinyPNG, and ShortPixel. I downloaded each result, measured the actual output bytes, and calculated SSIM with the same scikit-image workflow used for DigImg's own measurements. This is a…
A comparative analysis was performed on four distinct image types using three different image compression tools: DigImg, TinyPNG, and ShortPixel. The goal was to measure file size and quality using the SSIM metric. The results indicated that each tool performed differently depending on the image type.
For photographic images, DigImg's JPEG output was smaller than the competitors', but TinyPNG maintained the highest SSIM score among the JPEG results. DigImg's WebP output was the smallest of the JPEG files, although it had a lower SSIM score.
Transparent logos were effectively tied between all three tools. The flat graphic was tied between DigImg and ShortPixel, while TinyPNG slightly trailed behind. For UI screenshots, ShortPixel produced the smallest file, while DigImg produced the smallest pixel-exact lossless PNG. These results demonstrate that a useful comparison should display both size and quality, and should clarify whether the smaller file is lossy or not.
The test shows that there is no single winner across all image types - the optimal choice depends on the specific image and its intended use. Lossless compression is a practical choice for logos, diagrams, and screenshots, as preserving exact pixels is often more critical than reducing file size. In this test, all three tools produced pixel-exact outputs for the logo and flat graphic.
However, ShortPixel's output was smaller, while DigImg retained exact pixels. For UI screenshots, the trade-off between size and quality should be carefully considered, as a few hundred bytes saved may not be worth sacrificing the quality of text or sharp edges.
One advantage of using DigImg is its browser-local processing, which ensures no user image uploads occur during the workflow. This is particularly important for client assets, unpublished product images, and private screenshots. However, it is important to note that not all browser-based tools follow this practice. Other options like Squoosh also offer browser-local processing.
The results of this test should be taken as a spot check and not a definitive verdict. Factors such as methodology, image content, output format, metadata handling, and quality settings can significantly impact the results. Therefore, it is crucial to treat the data as a worked example and run your own images through the tools before making a final decision.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
