What is a QM file?
A .QM file is a Qt Compiled Translation Source File. The Qt Group uses these files to store localized text for software applications built with the Qt framework. Developers use Qt Linguist to translate text, which is initially saved as a human-readable .TS file. This source file is then compiled into a .QM file. The .QM format is binary. This design allows the application to load translations very quickly.
How to open QM files?
Because .QM files contain compiled binary data, you cannot read them with a standard text editor. If you want to view or edit the translations, you generally need the original .TS file and Qt Linguist. If you only have the .QM file, you can use the `lconvert` command-line tool provided by the Qt framework to decompile the binary file back into a readable format.
Best practices and troubleshooting
Always keep your original .TS source files. The .QM file is only meant for the final software release. If your Qt application displays the wrong language or missing text, verify that the correct .QM file is located in the application directory. Ensure that the file matches the expected language code.
Software and tools
The primary software to manage these translations is Qt Linguist. Command-line utilities like `lrelease` (for compiling) and `lconvert` (for converting) are also standard tools used by developers working with the Qt framework.
Summary
viewer.online/qm can analyze .QM files to identify the exact format and creator software, inspect the file structure, extract readable text, and check whether an online preview is available. This makes viewer.online/qm highly useful for identifying, inspecting, and understanding .QM files without installing the full developer toolkit or dealing with software compatibility problems.