Fit XPS spectra — and
know when your fit is wrong.
A free, cross-platform XPS peak-fitting app with a built-in fit auditor and a citation-backed reference database. The modern replacement for XPSPEAK 4.1.
Everything XPSPEAK did, plus the checks that keep your fits defensible
On a modern Mac/Windows interface — no Python, no account, no peak ceiling.
Built-in fit auditor
FWHM sanity, reference binding-energy checks, doublet integrity, lineshape, satellites, residual z-score, BIC — and a leave-one-out test that flags peaks the data doesn't require.
Citation-backed database
24 elements with binding energies, spin-orbit parameters and RSFs — every value with its literature source. One-click recipes; add your own references.
Truly cross-platform
Native macOS and Windows. No 5,000-point / 51-peak ceiling like XPSPEAK. No Python, no account — free forever under GPLv3.
Imports everything
.dat / .csv / .xlsx / .xls, Thermo Avantage multi-sheet, VAMAS, or paste two columns from Excel. KE→BE conversion built in.
Is your fit
defensible?
A flat residual isn't enough. PikaXPS's auditor runs the checks a careful reviewer would — and a statistical leave-one-out test that catches the "I added a peak and nothing changed" trap.
See how it worksAn honest comparison
PikaXPS is the free, Mac-friendly, validation-focused option.