COPASI

COPASI: Biochemical System Simulator

COPASI is a software application for simulation and analysis of biochemical networks and their dynamics.

COPASI is a stand-alone program that supports models in the SBML standard and can simulate their behavior using ODEs, SDEs, or Gillespie's stochastic simulation algorithm. Arbitrary discrete events can be included in such simulations. COPASI provides a set analysis methods and parameter estimation, a list of all features can be found here.

Most recent News

Release

COPASI 4.47 (Build 309) Released

Stefan Hoops: 2026-08-13 01:00:00 +0000

The COPASI team announces the immediate availability of the stable release COPASI 4.47 (Build 309).

A new release of COPASI has been made available. Please visit our free download page to retrieve this latest development release. Please note this version is released under the Artistic License 2.0, which is an OSI approved license. This license allows non-commercial and commercial use free of charge.

Release Date: August 13, 2026

New Features since COPASI 4.46 (Build 300)

  • Simulation Engine
    • Multi threading for population based optimization methods Differential Evolution, Evolutionary Programming, Evolution Strategy (SRES), Genetic Algorithm, Genetic Algorithm SR, Particle Swarm, and Scatter Search speeding up optimization and parameter estimation tasks.
  • Command Line (CopasiSE)
    • Added option to import and export task settings.

Bug Fixes and Enhancements since COPASI 4.46 (Build 300)

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Release

COPASI 4.46 (Build 300) Released

Stefan Hoops: 2026-01-23 01:00:00 +0000

The COPASI team announces the immediate availability of the stable release COPASI 4.46 (Build 300).

A new release of COPASI has been made available. Please visit our free download page to retrieve this latest development release. Please note this version is released under the Artistic License 2.0, which is an OSI approved license. This license allows non-commercial and commercial use free of charge.

Release Date: January 23, 2026

New Features since COPASI 4.45 (Build 298)

  • Graphical User Interface (CopasiUI)
    • Parameter Estimation: Start in Steady State can now be selected per experiment..
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Release

COPASI 4.45 (Build 298) Released

Stefan Hoops: 2025-04-22 01:00:00 +0000

The COPASI team announces the immediate availability of the stable release COPASI 4.45 (Build 298).

A new release of COPASI has been made available. Please visit our free download page to retrieve this latest development release. Please note this version is released under the Artistic License 2.0, which is an OSI approved license. This license allows non-commercial and commercial use free of charge.

Release Date: April 22, 2025

New Features since COPASI 4.44 (Build 295)

  • Graphical User Interface (CopasiUI)
    • Added a new tool which attempts to convert ODEs into reactions.
    • Added a menu entry which allows definition and subsequent execution of user defined tools.
  • Standards
    • SBML Import added an option determining how to handle the import of initial values initial references.
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Release

New modeling tool: sbmodelr

Pedro Mendes: 2024-11-12 20:30:00 +0000

sbmodelr - New modeling tool to create complex models

The COPASI team is happy to announce a new tool, called sbmodelr, which is intended to construct large models that are composed of repeating units. Essentially, you start with a base model and then tell sbmodelr to create a number of repeat units of that model, as well as which model entities interact between units.

sbmodelr is a python-based command line utility that reads a systems biology model, encoded in COPASI or SBML formats, to create a new model that is composed of several connected units that are replicates of the base model. These units may be organized as an arbitrarily connected network, a 2D rectangular grid, or a 3D cuboid array. Each unit contains a complete copy of the original model with all its species, reactions, compartments, events, and global quantities.

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Release

COPASI 4.44 (Build 295) Released

Stefan Hoops: 2024-07-08 01:00:00 +0000

The COPASI team announces the immediate availability of the stable release COPASI 4.43 (Build 288).

A new release of COPASI has been made available. Please visit our free download page to retrieve this latest development release. Please note this version is released under the Artistic License 2.0, which is an OSI approved license. This license allows non-commercial and commercial use free of charge.

Release Date: July 08, 2024

Bug Fixes

  • Command Line (CopasiSE)
    • No files are created or modified when the option –validate is given.
  • Simulation Engine
    • Time Course Task: The methods RADAU5 now correctly supports the option Suppress Output Before …
    • Time Course Task: The hybrid methods Hybrid LSODA & Hybrid Runge-Kutta now supports automatic step size correctly.
    • Optimization and Parameter Estimation Tasks: The method Praxis now correctly terminates if the if solution is within the tolerance.
    • Parameter Estimation Task: The Method Evolution Strategy (SRES) now checks the functional constraints like other methods.
    • Metabolic Control Analysis and Linear Noise Approximation Tasks: The result now contains the Steady-State result.

More information can be found in the changelog.

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