Amazon S3 is an inexpensive cloud storage service that you may use for online backup as well as for hosting static resources of your website like web images, Flash video, audio files, etc.

Amazon built the service primarily for web developers and that partially explains why they didn’t care about providing a web interface or some sort of desktop application to at least help their non-techie users organize S3 files more easily.

Third-party developers then jumped in and, as a result, we now have some brilliant Amazon S3 Clients (lot of them are free) that make S3 account management almost as easy as managing files in Windows Explorer. But since choices can lead to confusion, here’s a quick round-up to help you pick the right client for Amazon S3 with CloudFront.

The Best Amazon S3 Tools for Windows, Mac & Linux

S3 Browser – With S3 Browser, you can manage buckets and files on multiple S3 accounts from the same interface. You can edit custom headers of individual files /folders and there’s a progress bar to indicate the transfer status of file transfers in real time. S3 Browser comes in a portable version as well for use on USB drives but the program is free for personal use only.

Cross FTP – This is also an FTP client so you also upload or download files from Amazon S3 storage like the traditional FTP file transfer ($25). You can create buckets, set access control or even change the CloudFront distribution settings of individual files with Cross FTP.  unique feature is scheduled batch transfer – you may put any number of files in a queue and upload them to S3 in one go later.

S3 for Live Writer – If you use Windows Live Writer for writing your blog and use Amazon S3 for hosting files, this Live Writer plugin may come handy. It will help you upload images, documents and other files to your S3 account directly from Windows Live Writer or you may use it for browsing files that already exist on your Amazon S3 account and insert links to those files into your blog posts. 

CloudBerry Explorer – This Windows-only Amazon S3 client is very responsive and has the most beautiful interface of them all. With CloudBerry Explorer, you can connect to multiple S3 accounts simultaneously (shown in separate tabs), set up bucket logging to track usage, control file permissions and also delete (or temporarily disable) CloudFront distributions. The upcoming version of CloudBerry Explorer will also support custom HTTP headers.

Transmit – This is a popular FTP client that also lets you upload, download and manage your online Amazon S3 storage like a native Mac app ($30). You can upload files to either US or European S3 servers but there’s no support for CloudFront. Another Mac only FTP client that has built-in support for S3 is Cyberduck.

WordPress Plugin – This plugin overrides the default WordPress blog settings and all images, podcasts, etc. attached to blog posts are automatically uploaded onto your Amazon S3 buckets. It also adds an "Amazon S3" to the WordPress interface allowing you to browse S3 files that were not upload via WordPress. The plug can set the HTTP expiration header of your blog images to a future date thus reducing your bandwidth bills.

S3Fox Organizer – This powerful extension integrates Amazon S3 right into your Firefox browser. You may upload or download files from multiple S3 accounts, synchronize local folders with S3, modify Access control policies of buckets or set an expiry data for files such that they become unavailable after a given time. The latest version of S3 Fox can help you help manage S3 CloudFront distributions right from Firefox.

Bucket Explorer – This is the most "complete" S3 client that’s available for Mac, Windows and Linux ($50). With Bucket Explorer, you can perform almost every S3 operation from the desktop including Bucket Logging, file comparison, batch file transfers, setting ACL and custom headers (meta data). It will also help you manage all your Amazon CloudFront distributions from the desktop itself.

Another unique feature of Bucket Explorer is the recycle bin so that you don’t lose data if you accidental delete a file or a bucket from your S3 account. And the same license provides a command line version of the tool as well for power users.

Gladinet – This will mount your Amazon S3 folders to your Windows Explorer and you can therefore interact with S3 buckets / files as if you were accessing a local folder. You can drag and drop files in between Amazon S3 online storage and Windows Explorer. Other than S3, Gladinet Cloud desktop also works with Google Docs, Live Skydrive and Picasa.

Mobile Phones: If you need to access /upload Amazon S3 files on a mobile phone, check S3Anywhere for Google Android handsets, OpenS3 for accessing S3 on iPhone / iPod Touch and Bucket Upload for a J2ME device like the Nokia N series or Sony Ericsson cell phones.

Conclusion: Bucket Explorer supports all features of Amazon S3 but if you aren’t willing to spend $50 on an Amazon S3 client, CloudBerry Explorer for Windows is a good choice. If you are using a different platform or need to set up CloudFront with your Amazon S3 account, go with S3 extension for Firefox.

Related Tutorials on Amazon S3 & CloudFront