6.2 Extension IDs Each extension has an extension ID that follows the browserext:// protocol. For example browserext://MyExtension_c1wakc4j0nefm/options.html browserext://dfcijpibodeoenkablikbkiobbdnkfki/options.html The algorithms that generate these IDs are different for each browser. To access these resources, do not hardcode the ID generated by a particular browser. Instead, use the runtime.getURL() method to convert a relative file name or path to the absolute name or path, which includes the extension ID.