- Developer
- Limit Point Software
- Size
- 4.3 MB
- Operating System
- Mac
- License
- Demo
- Category
- Internet-Network
Download Links
- Download
- Blue Crab 4.9.20
Blue Crab is a versatile program that you use to copy the contents of a web site to your computer, in whole or in part.
With Blue Crab you can download all the content including HTML, PDF, graphics, video, file archives, etc., or use selective filtering to restrict downloads to specific kinds of files. For example, you can choose to save only the JPEG images Blue Crab finds, or just the PDF’s. Blue Crab also supports "batch downloading" where you can collect a bunch of URLs (say by dragging them out of a browser window) then downloading them all at once.
Starting with a single URL Blue Crab begins traversing the site by following the links on the textual pages it finds, HTML, CSS, etc. Blue Crab does not stray off the domain of the starting URL; in other words it won’t download the whole web! Moreover, you can restrict Blue Crab to a subset of the given website by specifying strings that must match parts of the URL. There is also a convenient "stay in folder" option in every grabber window which restricts the crawl to URLs whose path must begin with the same path of the starting URL. Use the Configuration editor to modify the behavior of a grab.
Blue Crab has a special feature called the "Media Grabber" which you can use to easily download just the graphics, movies or PDFs on a website. When finding images, you can view a mini slide show as they are downloaded. You also have the option of "flattening" the download directory, i.e. putting all the downloaded images into one folder, or preserving the folder structure on the server (just as when downloading a complete website for offline viewing.)
Blue Crab sports two types of "grabbers" for crawling a website. The first kind, called "classic" since it was the initial grabber type in Blue Crab, uses the original methods provided by the Mac OS for downloading URLs. The classic grabber shows very detailed progress statistics, and in particular the server’s HTTP response headers in log format (which provides information like server type.) The alternative "quick" grabber is the newer type, and forms the basis of the "download one page" and "media" grabbers. The term "quick" comes from the fact this grabber uses newer Mac OS technology and doesn’t provide as much progress statistics as the classic version. In benchmark testing it can be up to 20% faster. In addition, for certain websites, one type of grabber may yield better results than another.
