How to download a webpage's all images at once?

Automator

Use OS X's Automator.app to find, extract, and save the images from your current web page. The combination of Actions needed are:

• Get Current Webpage from Safari
• Get Contents of Webpages
• Save Images From Web Content

To learn more about using Automator, see Apple's Mac Basics: Automator.

Terminal

An alternative approach is to use curl through the command line, What's the fastest and easiest way to download all the images from a website.

Using wget:

wget http://en.wikipedia.org/wiki/Service_Ribbon -p -A .jpg,.jpeg,.png -H -nd

-p (--page-requisites) downloads resources like images and stylesheets even when you don't use -r. -A specifies suffixes or glob-style patterns to accept. -H (--span-hosts) follows links to other domains like upload.wikimedia.org. -nd (--no-directories) downloads all files to the current directory without creating subdirectories.

You can install wget with brew install wget after installing Homebrew.

You might also just use curl:

curl example.tumblr.com | grep -o 'src="[^"]*.jpg"' | cut -d\" -f2 | 
        while read l; do curl "$l" -o "${l##*/}"; done

Downloading images from Tumblr or Blogspot:

api="http://api.tumblr.com/v2/blog/example.tumblr.com/posts?type=photo&api_key=get from tumblr.com/api"
seq 0 20 $(curl -s $api | jq .response.total_posts) |
    while read n; do
        curl -s "$api&offset=$n" |
            jq -r '.response.posts[].photos[].original_size.url'
    done | awk '!a[$0]++' | parallel wget -q

curl -L 'http://someblog.blogspot.com/atom.xml?max-results=499' |
    grep -io 'href="http://[^&]*.jpg' | 
    cut -d\; -f2 |
    awk '!a[$0]++' |
    parallel wget -q