How PikaXPS compares
There are good tools for XPS peak fitting. Here’s an honest comparison so you can pick the right one — PikaXPS is the free, Mac-friendly, validation-focused option.
| PikaXPS | XPSPEAK 4.1 | CasaXPS | KherveFitting / LG4X | |
|---|---|---|---|---|
| Price | Free (OSS, GPLv3) | Free | €830+ academic, perpetual | Free (OSS) |
| Platforms | macOS + Windows | Windows only | Windows (Mac via emulation) | Win/Mac/Linux |
| Built-in fit auditor | ✅ | ❌ | ❌ | ❌ |
| Citation-backed reference DB | ✅ | ❌ | partial (you look it up) | ❌ |
| One-click fitting recipes | ✅ | ❌ | ✅ | ❌ |
| Doublet + satellite peak types | ✅ | limited | ✅ | partial |
| Peak / point limits | none | 51 peaks / 5,000 points | none | none |
| Actively maintained | ✅ | ❌ (1999) | ✅ | ✅ |
When to use what
- CasaXPS is the paid standard with decades of installed base; if your lab already standardises on it and reviewers expect its output, keep using it. PikaXPS is complementary — a free Mac-native option, a teaching tool, and a second opinion that audits your fits.
- XPSPEAK 4.1 is what many students still use for lack of a free alternative. PikaXPS is what XPSPEAK should have become in 2025: cross-platform, no peak limits, and validated.
- KherveFitting / LG4X are excellent free, cross-platform, lmfit-based tools. PikaXPS’s difference is the automated fit auditor and the citation-backed reference database they don’t have.
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