Command Line Parameters

Firefox recognizes many (many!) command line parameters. Overview documentation of these parameters lives here.

Known parameters




On Windows, -osint serves two purposes. Most importantly, it signals that the command line is untrusted and must be sanitized. Command lines with -osint are rejected unless they have a very specific structure, usually firefox.exe -osint -url URL or firefox.exe -osint -private-window URL: refer to the EnsureCommandLineSafe function. These command lines are produced by apps delegating to Firefox, and the resulting URL may not be correctly quoted. The sanitization process ensures that maliciously chosen URLs do not add additional parameters to Firefox. Secondarily, the -osint parameter signals that Firefox is being invoked by Windows to handle a URL: generally a registered file type, e.g., .html, or protocol, e.g., https.