From Excel to app — or not
Stuck with a spreadsheet?
Drop it here, answer six short questions, and get honest advice: keep it as a spreadsheet, move it to a database, or turn it into an application. No account, and your file stays in your browser.
Upload your spreadsheet
.xlsx, .xlsm or .csv — no account, no email address
Your file never leaves your computer. We read it here in your browser and send only the structure — counts, formula tallies and column names — along with your six answers. Never your rows, amounts or customer names. You will see exactly what gets sent, and you can anonymise the column names.
Step 1
What we found in your file
file.xlsx
Read in your own browser. These are the signals the advice partly rests on.
Step 2
Six things we cannot measure
Where we spotted something in the file, the answer is filled in already. Correct it freely — the proposal gets sharper for it.
Our recommendation
Your answers to the six questions
What it would take
An estimate based on your file and your answers.
What the application would do
This is a proposal, not a commitment. It is based on the structure of your file and your six answers — not on your actual process, your systems, or whatever else is in play. In practice the odd point turns out to be unnecessary or not feasible, and a few usually get added. Read it as a picture of what is possible, and as the start of the conversation.
Want to work this out together?
A 30-minute introductory call about the process behind this file. If it turns out you don't need us, we'll say so.
What actually improves
Not “be more careful” — the mistake becomes impossible
Every point below comes from what we measured in your file or from what you answered.
Field audits find errors in 24 to 94% of business spreadsheets; a recent study put it at 94% of the files used in decision-making. The sting is in the self-assessment: people estimate their own error rate at 10 to 18%, while 86% had in fact made one. The problem is not carelessness — you simply cannot see your own mistakes.
Why work with us
The things you're worried about, and what we do about them
Keeping it running falls under our managed data foundation, monthly and cancellable each month: hosting, backups, checks on the connections, updates, and keeping up when your accounting package or shop changes an API — which happens a few times a year. That is the difference between a project and a service.
The source code and the data are yours, in your own environment or in escrow. If we stop, your application does not.
Which is why we run in parallel for a month. You switch when it is proven, not when we say it is finished.
For a self-contained file that changes nothing: the application, the hosting and the support work the same anywhere, and we work in English. The real limit is integrations — we connect to systems we know well. If your file needs software we have never touched, we say so up front.
The screen is the easy half. The connections to your accounting system, your shop and your bank are the hard half — that is where it is decided whether the numbers are right and reconcile, not whether it looks good.
You get the process on paper: which data comes from where, which rules apply, who may do what. That is what an auditor asks for, and what currently lives only in someone's head.
To the cent, before you switch
We run both for a month. Before the switch we put the totals side by side: what the application says must match what your spreadsheet says, to the cent. If it doesn't, we don't go live.
And if you'd rather do it yourself
Why an application
What you gain isn't speed — it's that the numbers are right
An application isn't a prettier spreadsheet. The difference is in what gets written down, and therefore in what can no longer go wrong.
The rules are fixed, not in someone's head
In a spreadsheet the logic sits in formulas nobody dares touch, and in habits only one person knows. In an application you write those rules down once and they apply to everyone. What "revenue" means, when an order counts, which discount is allowed — that becomes an agreement instead of a habit.
business rules capturedEveryone calculates the same way
Five copies of the same file are five answers to the same question. One application is one answer. Consistency isn't tidiness — it's the difference between a number you can act on and a number you have to hold a meeting about.
one source, one outcomeAnd only then can you point AI at it
A language model that doesn't know "revenue" excludes intercompany, or that status 7 means cancelled but still invoiced, will hand you the wrong figure with complete confidence. Captured rules and a description on every field aren't bureaucracy: they're the precondition for doing anything with AI that you'd dare to believe.
a data catalogue as a by-productHow it works
Three steps, no account
1. Your file is read locally
Sheets, rows, formulas, references to other workbooks, date fields and the file properties. That happens in your browser, not on our server.
2. You answer six questions
Who works in it, how often it is updated, who reviews it, where the data comes from, where it breaks down, and whether other companies work the same way. Whatever we could measure is filled in already.
3. You get a recommendation
One of three routes, with reasoning. For “application” you also get an estimate of size and build time.
What you don't get
No newsletter, no phone call because you uploaded something, and no sales pitch when the advice is to keep it as a spreadsheet.
More background: when a spreadsheet is worth replacing and how we build one and keep it running.
Frequently asked
What people ask first
Is my spreadsheet uploaded to a server?
No. The file is read in your own browser. Only the structure — counts of sheets, rows, formulas, and the column names — plus your six answers are sent. Never cell contents, amounts or customer names. You see exactly what gets sent, and you can anonymise the column names.
Do you work with clients outside the Netherlands?
Yes, for self-contained spreadsheets. The application, the hosting and the support travel fine, and we work in English. Time zones within a few hours of Central European Time overlap comfortably.
The one real limit is integrations. We connect to systems we know well — mostly European accounting and e-commerce platforms. If your file needs to pull from software we have never touched, that is a genuine risk and we will tell you up front.
When should a spreadsheet become an application?
When several people work in it, it is rebuilt every period, someone else reviews it, the data comes from several systems, it breaks under its own size, and other companies have the same file. Four or more of those six usually means an application pays for itself. With one or two, a spreadsheet is simply the right tool.
Can I not just do this with ChatGPT or Claude myself?
For the analysis, yes — and it will do it well. What it does not do: build the connections to your accounting system or shop, make it secure and compliant, and keep it running three years from now when a supplier changes an API. That last part is what this is about.
Does it work with Google Sheets or CSV?
CSV works directly. For Google Sheets, use File → Download → Microsoft Excel (.xlsx) and upload that. Formulas are preserved that way, and formulas are exactly what we look at.
Contact
Want to talk it through?
Three fields, nothing more. You'll get an honest answer — including when that answer is that you don't need us.