Explore HITRAN Spectra on macOS

Why use HitranLab?

HitranLab complements HITRANonline and HAPI by providing a fast, native macOS workflow for interactively exploring HITRAN line-by-line data—without writing code.

Load a .par file, select molecules and isotopologues, inspect individual transitions, simulate broadened spectra, compare absorbance and transmittance, and export results from one focused desktop application.

HAPI, MODTRAN, and custom research software remain better suited to automated batch processing, advanced atmospheric modeling, and highly specialized calculations. HitranLab is designed for quick visual exploration, straightforward simulation, teaching, and routine spectral work.

Inspect HITRAN data

• Load HITRAN-format .par files

• Filter by molecule, isotopologue, spectral range, and minimum line strength

• Display stick spectra using linear or logarithmic line-strength scaling

• Inspect line position, strength, lower-state energy, isotopologue, and quantum assignments with the interactive cursor

Simulate spectra

• Generate absorbance, transmittance, or percent-transmittance spectra

• Apply Gaussian, Lorentzian, or pseudo-Voigt broadening

• Set molecule-specific burdens in ppm·m

• Display the horizontal axis as wavenumber (cm⁻¹) or wavelength (µm)

Explore and export

• Zoom into narrow spectral regions by dragging across the plot

• Calculate the integrated area of the displayed stick spectrum

• Export calculated data as CSV or text

• Export the plot panel as a JPEG image

• Evaluate the application with Demo Mode before downloading HITRAN data

Applications

• Explore and compare molecular infrared spectra

• Inspect HITRAN line positions, strengths, isotopologues, and assignments

• Generate spectra for teaching, demonstrations, or routine scientific work

• Export calculated data for additional analysis in other software