Word cloud based on frequencies in instance descriptions In response to the needs of researchers for access to real-world mixed integer programs, Robert E. Bixby, E.A. Boyd, and R.R. Indovina created in 1992 the MIPLIB, an electronically available library of both pure and mixed integer programs. Since its introduction, MIPLIB has become a standard test set used to compare the performance of mixed integer optimizers. Its availability has provided an important stimulus for researchers in this very active area. The library has now been released in its sixth edition as a collaborative effort between Arizona State University, COIN-OR, CPLEX, FICO, Gurobi, MathWorks, MIPCL, MOSEK, NUOPT, SAS, and Zuse Institute Berlin. Like the previous MIPLIB 2010, two main sets have been compiled from the submissions. The Benchmark Set contains 240 instances that are solvable by (the union of) today’s codes. For practical reasons, the benchmark instances were selected subject to various constraints regarding solvability and numerical stability. The much larger Collection Set represents a diverse selection regardless of the above, benchmark-relevant criteria. Download the instance sets as well as supplementary data, run scripts and the solution checker from our Download page.

Contact Us

The current maintainers of the website and its content are Ambros Gleixner and Gabriel Kressin. Contributions of new solutions to open instances are always welcome, and will be made available in periodic updates of the web page. Also, we are happy to provide additional instance tags upon request.


This page now hosts the new MIPLIB 2017. Find its predecessor MIPLIB 2010 on our Links page.

News & Status


Mar 25, 2020 Another month, another update! This time, we have 5 additional optimal and 20 incumbent solution submissions.
February 24, 2020 With the biggest update regarding optimal solutions so far, the realease of solution file version 13 includes 15 new optimal solutions and 7 better incumbent solutions. Additionally, b1c1s1 was solved within one hour and thus moved from ‘hard’ to ‘easy’.
February 11, 2020 A new year - a new decade - starts, and with that come some changes. We are sad to announce long time maintainer Gregor Hendel will no longer be responsible for MIPLIB 2017. We are very grateful for his significant contributions to the creation of MIPLIB 2017 and the fantastic job he did in maintaining this web page and all information listed on it! From now on, Gabriel Kressin will maintain the MIPLIB 2017 web page. Additionally, this update brings 91 improved incumbent solutions, of which 2 are the first known solutions for their respective instances and 3 are proven optimal solutions.
December 19, 2019 MIPLIB 2017 celebrates its largest update so far. 10 instances have been reported solved for the first time, and another 115 instances have improving solutions.
November 20, 2019 With the 1st anniversary of MIPLIB 2017, it is time for another update. 13 new solutions have been added, 5 of which on instances for which no solution was known so far. Please see the CHANGELOG for details. We would like to warmly thank all contributors of new/improving solutions for their continuous effort.

For all news, click here, or view the complete Changelog.


Frequencies of categories easy/hard/open

Frequencies of categories easy/hard/open

‘Easy’ means that the instance could be solved within less than one hour using an out-of-the-box solver on standard desktop computing hardware, ‘hard’ stands for instances, that have been solved in longer runs possibly using nonstandard hardware and/or algorithms, whereas ‘open’ means, that the instance has not yet been reported solved.


An article about the selection methodology is currently under preparation. A preprint can already be accessed on Optimization Online. Until it is finished, please cite this webpage.

  Title                    ={{MIPLIB} 2017},
  Note                     ={http://miplib.zib.de},
  Year                     ={2018},
  Key                      ={miplib2017}


Most of the data files on this site have been converted, some optimal solutions are gathered from papers and some data was typed in by hand or generated by automatic solution extraction programs. While we took every effort to make no mistakes, we cannot guarantee that everything is correct. If you find any errors or have doubts about a solution, please contact us.

Last Update Mär 25, 2020 by Gabriel Kressin
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© 2019 by Konrad-Zuse-Zentrum für Informationstechnik Berlin (ZIB)