For most users, the web interface is secondary. You want subtitles to automatically pop up while streaming. Here is the definitive guide to changing your Kodi subtitle source to a mirror.

If you cannot find a working Open Subtitles mirror, or if you are concerned about the safety of proxy sites, there are excellent alternatives available.

Based on current community consensus, the following mirrors have been reported as stable:

Have a working Open Subtitles mirror we missed? Let the community know in the comments (but please, no direct links if your local laws prohibit them—obscure references only).

Even with a good mirror, things go wrong. Here is a rapid troubleshooting table: