Backends

A backend is the TeX-to-PNG pipeline. Three are supported; pick the one that matches your environment.

PDFLaTeX (default)

pdflatex → PDF → pdftoppm → PNG

pdflatex is part of every major TeX distribution (TeX Live, MiKTeX, MacTeX). pdftoppm is part of poppler-utils. This is the recommended backend because pdflatex handles the widest range of packages.

Packages: texlive-latex-base + texlive-fonts-recommended + poppler-utils

DPI: controlled by Options.DPI (default 150). The -r flag is passed to pdftoppm.

Pin it:

termlatex.Options{Backend: termlatex.PDFLaTeX}

Tectonic

tectonic → PDF → pdftoppm → PNG

Tectonic is a self-contained TeX engine that downloads the packages it needs on first run. No manual TeX installation — just install the tectonic binary.

Packages: just tectonic + poppler-utils

Trade-off: first render may take a few seconds while TeX packages download; subsequent renders hit the cache and are fast.

Pin it:

termlatex.Options{Backend: termlatex.Tectonic}

DVIPng

latex (DVI mode) → DVI → dvipng → PNG

latex produces a DVI file; dvipng converts it directly to PNG. This is the classic pipeline and produces the sharpest output at low DPI because dvipng knows the TeX metrics directly.

Packages: texlive-latex-base + texlive-fonts-recommended + dvipng

Limitation: some packages (TikZ, PGFPlots, packages that load PDFs) require PDF mode and won't work here. pdflatex/tectonic is the right choice for those.

Pin it:

termlatex.Options{Backend: termlatex.DVIPng}

Auto-detection order

When Backend is Auto (the default), Detect() checks:

1. pdflatex + pdftoppm both in PATH → PDFLaTeX
2. tectonic + pdftoppm both in PATH → Tectonic
3. latex + dvipng both in PATH → DVIPng
4. None found → ErrNoBackend