We consider hashes of files of any size right in the browser

There are a lot of sites for counting hashes (MD5, SHA1, SHA2) files in the network, however, all the services that I could find have the same drawback: the file size is limited. You also need to first upload the file to the server to get the result of the calculations. It is very uncomfortable.

Therefore, I decided to create a small service MD5 File , the calculation of which will occur directly in the user's browser. There is no need to upload files to the server (we save traffic and time) and it is possible to work with files of any size.

Picture and some information under the cut

Using the service is very simple, open the page md5file.com/calculator and throw the necessary files there:
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Currently MD5, SHA1 and SHA256 hashes are being calculated.

File management requires browser support for the File API , which means that it will not work in IE 9. The Web Workers API is also used so that all calculations are performed in several threads.

In the latest versions of Firefox and Chrome everything should work. However, as it turned out, Firefox 7 does not seem to support cloning of the File object into the Worker stream, and Chrome transferOption into PostMessage. I had to try a little to make a universal solution.

So that the use of RAM does not increase in proportion to the size of the files. I rewrote the hash sum calculation algorithms so that they can count in blocks and memorize the current state. Thus, the current algorithm works does not depend on the size of the files.

I hope this simple service will be useful to you.

PS At the moment the service launches as many threads as you have selected files. I plan to add the ability to customize the queue of files a little later.