Out of the box, Subversion does not support the ability to view previous revisions via a web browser, however if you enable ‘Auto Versioning’ (aka WebDAV), this feature will be available to you.

For more information on setting up WebDAV for Subversion check out: http://svnbook.red-bean.com/en/1.2/svn.webdav.autoversioning.html

If you do have WebDAV functionality enabled, you can view previous revisions by using the following url construct as a guide:

http://svn.somedomain.com/repos/!svn/bc/14

’14′ in the above example represents revision 14.