Photoshop – Export As – Why no Progressive JPG Option
Why does the latest version of Photoshop not have the JPG Progressive option as a choice when using the Export As option and only in the Legacy Save for Web?
Export As offers higher quality compression, so it a bit disappointing that you don’t get to use it if you are optimising your images for websites with Progressive.
Google PageSpeed – Insights – Optimize Images
JPEG is a lossy format. The compression process removes visual details of the image, but the compression ratio can be 10x larger than GIF or PNG.
- Reduce quality to 85 if it was higher. With quality larger than 85,
the image becomes larger quickly, while the visual improvement is
little.- Reduce Chroma sampling to 4:2:0, because human visual system
is less sensitive to colors as compared to luminance.- Use progressive format for images over 10k bytes. Progressive JPEG usually has higher
compression ratio than baseline JPEG for large image, and has the
benefits of progressively rendering.- Use grayscale color space if the
image is black and white.
Export As
Save for Web
Answer
Given that internet and phone data speeds have increased exponentially since the inception of the “Progressive” option, the page load speed gained by progressive jpegs has largely lost its significance.
If an image is correctly optimised using the “Baseline” option (especially small to medium sized images), there is little advantage. This is especially true when you consider the downside of “progressive”, i.e. multiple HTTP requests which will also have a bearing on the page speed.
That is why it is recommended to combine all CSS files into one file, and likewise js files, in order to minimise the HTTP requests.
Attribution
Source : Link , Question Author : Invariant Change , Answer Author : justcoastin
