The Sensitivity Analysis For Everyone (SAFE) toolbox

SAFE logo

The SAFE Toolbox provides a set of functions to perform Global Sensitivity Analysis. It implements several methods, including the Elementary Effects Test, Regional Sensitivity Analysis, Variance-Based (Sobol’) sensitivity analysis and the PAWN method. SAFE was originally developed for the Matlab/Octave environment (Pianosi et al. 2015) but was then made available also in R and Python.

Who uses SAFE

SAFE was first released in 2015. Until 2022, when the code was moved to GitHub, SAFE was distributed open-source and free-of-charge through a bespoke website ( upon filling in a download request. This distribution model enabled us to monitor the number of downloads and gathering contact details and some basic information about the users (country, research field, etc).
In 2018, we used these information to run a survey of the users community at the time, and get their evaluation of SAFE. The results of this survey are discussed in Pianosi et al (2020). As of February 2023, when the website was closed and the code moved to Github, the toolbox had been downloaded over 4000 times from students and researchers from 160 different countries and across a range of areas in engineering and science. A visual summary is available here.


The SAFE Toolbox is available on GitHub in three versions:

Use SAFE freely but please cite the paper Pianosi et al. (2015) in any publication presenting results obtained using SAFE.

Learn more


Pianosi, F., Sarrazin, F., Wagener, T. (2015), A Matlab toolbox for Global Sensitivity Analysis, Environmental Modelling & Software, 70, 80-85.

Pianosi, F., Wagener, T., Sarrazin, F. (2020), How successfully is open-source research software adopted? Results and implications of surveying the users of a sensitivity analysis toolbox, Environmental Modelling & Software, 124.


This software is distributed under the GNU Public License Version 3.


SAFE was originally developed in Matlab by Francesca Pianosi, Fanny Sarrazin and Thorsten Wagener at the Department of Civil Engineering at the University of Bristol. The R version was developed by Isabella Gollini and Valentina Noacco. The Python version was developed by Fanny Sarrazin, and Jupyter Notebooks were developed by Andres Penuela-Fernandez.


The development of SAFE was originally supported by the UK Natural Environment Research Council through the Consortium on Risk in the Environment: Diagnostics, Integration, Benchmarking, Learning and Elicitation (CREDIBLE) [NE/J017450/1]. The further development of SAFE, including the implementation of the Python version, has been supported by the UK Engineering and Physical Sciences Research Council through a Living with Environmental Change Fellowship [EP/R007330/1] and the EPSRC Impact Acceleration Account.