Content-Type Fixer is a subscription-based Firefox extension designed to enhance file download management by correcting Content-Type headers. This utility ensures that files are downloaded with the appropriate headers based on their extensions. Compatible with a variety of file types like .pdf, .docx, and .zip, it allows users to customize settings for optimal file handling. Users can enable automatic monitoring of downloads through a simple toolbar button, which indicates when the extension is active or paused.

The extension also addresses common issues with file names being truncated due to erroneous Content-Disposition headers. Users can force inline or attachment dispositions to control how files are handled upon download. Additionally, it offers a log feature to add custom Content-Types for unsupported files, making it a versatile tool for managing downloads effectively.