# texliveonfly > Downloads missing TeX Live packages while compiling `.tex` files. > More information: . - Download missing packages while compiling: `texliveonfly {{source.tex}}` - Use a specific compiler (defaults to `pdflatex`): `texliveonfly --compiler={{compiler}} {{source.tex}}` - Use a custom TeX Live `bin` folder: `texliveonfly --texlive_bin={{path/to/texlive_bin}} {{source.tex}}`