Balance or Scale // PerfectXL Spreadsheet Validation
PerfectXL Compare

The Incredible Story

It might be hard to believe, but PerfectXL Compare story didn’t start in some board room with marketing professionals trying to pinpoint the needs of big financial institutions. Our software came to existence though a combination of passions for Excel, computer science, and board games!

The story behind the developer

The mastermind behind PerfectXL Compare is Willem-Jan Meerkerk. He grew up in the Netherlands and since a young age has had a love for computers, he was amazed that these systems seemed so much more efficient than our own minds. This idea of systems and efficiency followed him into board games, he just loved optimizing his strategy and getting better and better each time he played. This idea followed him right into his choice of university and study, IT (Bachelors) and Computer Science (Masters) at the Technical University in Delft, one of the best technical institutes in the world.

Willem-Jan Meerkerk // PerfectXL

Why spreadsheet comparison?

Willem-Jan did incredibly well during both his bachelors and his masters, he loved the flexibility of the studies. The focus was not on just learning and using a programming language, but rather the concepts behind programming languages, and what makes software work. His flexibility, good grades, and clear passion for software made him a heavily sought after candidate for his thesis. He wanted to do this externally to get a feel for a business and to directly see the practical applications of the work he put in. PerfectXL director Mateo Mol came with a suggestion, a concrete question: “How to develop an intelligent and applicable strategy for comparing two spreadsheet files?” The fact that the question sounded simple didn’t bother Willem-Jan as he quickly realized the answer to this question was incredibly complex.

“I wanted to research something that was technically challenging, but with a concrete outcome which could be measured and hopefully even applied”

Willem-Jan Meerkerk,
MSc. Computer Science, TU Delft

TU Delft Campus // PerfectXL

Is this even possible?

The first hurdle came right at the start of the research project, the ever growing question, is this even possible? While there were some theoretical bodies of work on multi dimensional comparison, all flushed out algorithms dealt with very simple versions of comparison, like text comparison. A spreadsheet is infinitely more complex than this due to the rows and columns structure, which gives each data point a relative location and it will never be enough to simply do a ‘flat’ comparison of an Excel file. Answering this question was a challenge for Willem-Jan, his love of optimizing clear systems, structured in concrete steps seemed impossible with such an open ended research question which might not even have a good answer. 

The first signs of life!

In classic Willem-Jan fashion, he found a solution to streamline his research. He decided to take out the hardest part of problem and tackle that first, if the hardest question could be answered, then the process would suddenly become much easier. His first focus was the comparison of spreadsheet structure, columns and rows. Within a few months he had a prototype which could do this for even complex files and he knew he was on to something. This was a process unique to academic research because without it this process would not be possible, and measuring row and column inserts the way that Willem-Jan did was completely unique and does not exist in any known software algorithms. The next question was: “How can I visually represent these changes?”

The presentation

How the changes would be presented was incredibly important, because it was essential for making the tool practically applicable in the workplace, which is why Willem-Jan wanted to do an external thesis in the first place. This is where PerfectXL’s clients and partners really helped. With access to real users and their feedback, Willem-Jan was able to make the necessary decisions to develop a logical, simple front end to present the changes made by the comparison engine. He got an incredible score on his thesis based on this research and the prototype, and finished his studies June, 2019.

Willem-Jan Presenting PerfectXL Explore // PerfectXL

Further development & launch

After a well deserved break, Willem-Jan decided to officially start working at PerfectXL, and instantly started to develop his prototype into a fully capable tool. His hard work was rewarded in November 2019 when the tool was officially launched at the Bulgaria Excel Days conference, one of the biggest Excel conferences in Europe. An incredible event at which it was possible to showcase the power, simplicity, speed, and usability that this software has to offer. This drew the attention of many of the best Excel users in the world and the feedback was overwhelmingly positive.

Launch of PerfectXL Explore at Bulgaria Excel Days // PerfectXL

The sequel of the PerfectXL Compare story

PerfectXL Compare was honored in 2020 when it was named “Audit Extraordinaire” in the 2020 Financial Modeling Innovation awards. Willem-Jan is still working at PerfectXL, developing new tools and updating the PerfectXL Compare tool where needed. Young Willem-Jan’s love for computers and board games, and his obsession with constant improvement in systems, has led to an incredibly ground breaking, ingenious piece of software that helps Excel users worldwide. That’s the story behind PerfectXL Compare, and that’s why we are incredibly proud of what we have made!

“In hindsight this entire research process has been a great adventure. Developing something new can be frightening, but result is easily worth the uncertainty you start with.”

Willem-Jan Meerkerk,
MSc. Computer Science, TU Delft

Read more about Excel file comparison

On this page you will find a step-by-step walkthrough of the PerfectXL Compare tool.

This is the technical page for PerfectXL Compare. Here you will find information like system requirements, release notes, and answers to most questions about our software.

Here you’ll find a summation which aims to show the relevance and application of a compare tool based on the user tests we did while developing PerfectXL Compare.

We realize there are alternative solutions available in the realm of spreadsheet comparison, but PerfectXL Compare is in a different league. Below you will find a feature comparison with some of the market leaders in spreadsheet comparison.

Many nightmares have arisen because of confusion about the correct file versions of Excel documents. Learn more about version management.

What separates the great spreadsheets from the rest, is documentation! This will help future users of the spreadsheets to really understand your work.

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