MSFragger is an ultrafast database search tool for peptide identification in mass spectrometry-based proteomics. It has demonstrated excellent performance across a wide range of datasets and applications. MSFragger is suitable for standard shotgun proteomics analyses as well as large datasets (including timsTOF PASEF data), enzyme unconstrained searches (e.g., peptidome), open database searches (e.g., precursor mass tolerance set to hundreds of Daltons) for identification of modified peptides, and glycopeptide identification (N-linked and O-linked).

MSFragger is implemented in the cross-platform Java programming language and can be used three different ways:

  1. With FragPipe user interface
  2. As a standalone Java executable, which we recommend using with Philosopher pipeline
  3. Through ProteomeDiscoverer

MSFragger writes peptide-spectrum matches in either tabular or pepXML formats, making it fully compatible with downstream data analysis pipelines such as Trans-Proteomic Pipeline and Philosopher. See the complete documentation, including a list of Frequently Asked Questions. Example parameter files can be found here.

Supported file formats

The following spectral file formats can be searched directly with MSFragger, see the FragPipe homepage for compatibility with workflow components downstream from MSFragger.

Download MSFragger

Whether you run use FragPipe, PD, or the command line, you will need to download the latest MSFragger JAR file. See instructions for downloading or upgrading MSFragger.

Release Notes

The latest version of MSFragger was released on 2021-10-30. Check here for the full list of MSFragger versions and changes.

Running MSFragger


On Windows or Linux, the easiest way to run MSFragger is through FragPipe, which has a variety of built-in workflows for complete data analysis.

Philosopher pipeline

Complete command line analyses can be performed with Philosopher, see this tutorial for a step-by-step example.

ProteomeDiscoverer node

MSFragger and Philosopher (PeptideProphet) are also available as processing nodes in Proteome Discoverer (PD, Thermo Scientific). Currently, the MSFragger-PD node can be used in PD versions 2.2, 2.3 and 2.4.

Command line

See Launching MSFragger on the Wiki page.


For technical documentation on MSFragger (hardware requirements, search parameters, etc.), see the MSFragger wiki page.

Questions and Technical Support

See our Frequently Asked Questions (FAQ) page. Please post all questions/bug reports regarding MSFragger itself on the MSFragger GitHub page, or if more appropriate on FragPipe page or Philosopher page.

Requests for Collaboration

If you would like to propose a new collaboration that can take advantage of MSFragger and related tools, please contact us directly.

How to Cite

For other tools developed by the Nesvizhskii lab, see our website