Identify the 10 customers with the highest sales, what share of the total they represent and how each one has evolved month by month.
MKFactory Anonymizer · Free for Windows
Get your data ready for AI without exposing your customers
In the age of AI, you need more than ever a tool that prepares your data before you share it and restores it afterwards. Anonymizer is not an AI and doesn't connect to one: on your computer it swaps names, ID numbers, emails and phone numbers for codes so you can use ChatGPT, Claude or whichever AI you prefer without it seeing anyone, and then puts the real data back into its answer.
AI and your customers
AI doesn't need to know who is who
Uploading a customer spreadsheet to an AI takes seconds, and it means handing a third party the names, ID numbers, phone numbers and bank accounts of people who never agreed to that. Yet to find your best customers, anticipate churn or plan a campaign, the AI only needs to know that NOM-6RCN8ZM buys every month: it doesn't need to know his name is Gonzalo.
Your customers trusted you
Their personal data shouldn't end up on third-party servers or in a model's training data. With Anonymizer it never leaves your computer.
The AI analyses just as well
Amounts, dates and cities stay as they are, and each customer always gets the same code across every sheet. Joins, rankings and trends come out exactly the same.
Less risk, more peace of mind
You share far less: if the file leaks or gets reused, all anyone finds is codes. The only thing that can undo them, the key file, never leaves your computer.
See it on a real spreadsheet
This is the customer spreadsheet of an online coffee shop. Switch views to compare what you have with what the AI receives.
| Customer | First name | Surnames | ID number | Phone | City | Sales | |
|---|---|---|---|---|---|---|---|
| C0091 | Gonzalo | Castro Fernández | 18379710L | gonzalo.castro@example.com | 625 327 869 | A Coruña | €3,162.30 |
| C0043 | Marcos | Domínguez Marín | 29355149L | marcos.dominguez@example.com | 605 437 809 | Palma | €2,130.37 |
| C0051 | Carlos | Ortega Díaz | 66111679L | carlos.ortega@example.com | 655 210 487 | Barcelona | €2,072.83 |
| C0114 | Silvia | Ramos Díaz | 29654950S | silvia.ramos@example.com | 610 108 112 | Madrid | €1,783.95 |
| C0036 | Carmen | Moreno Cano | 77176101S | carmen.moreno@example.com | 638 505 218 | Madrid | €1,753.19 |
- Same customer, same code, in every sheet
- Cities, dates and amounts stay intact
- Automatically detects names, ID numbers, emails, phones, IBANs and addresses
How it works
Three steps, and your data never leaves your computer
1
Anonymize
Open your Excel or CSV file. Anonymizer detects the columns with personal data: check the boxes and click Anonymize. A copy with codes appears next to the original, along with an encrypted key file that stays with you.
2
Ask your AI
Outside Anonymizer, upload the copy to ChatGPT, Claude, Gemini, Copilot or whichever AI you already use and ask it anything. It works with the same data; your customers are just called NOM-6RCN8ZM.
Analyse these sales: who are my best customers and which acquisition channel retains them best?
Your best customer is NOM-6RCN8ZM NOM-9DXEJ5E, with €3,162.30 in sales. The top five account for almost 17% of revenue and all of them are on the Office plan:
- NOM-6RCN8ZM NOM-9DXEJ5E €3,162.30
- NOM-1H0Q67S NOM-Q10926G €2,130.37
- NOM-5WKYVWT NOM-3DHQZV9 €2,072.83
- NOM-YEHNNJE NOM-8J52WKH €1,783.95
- NOM-VZHN63S NOM-Z52XP2F €1,753.19
Customers who come through referrals stay the longest: 86.7% are still active, compared with 41.9% of those who come from the Marketplace.
This conversation happens in your AI, not in Anonymizer. It's a summary of a real AI answer using the sample spreadsheet.
3
Restore
Save whatever it gives back (a report, a Word document, a PowerPoint deck or an Excel file) and restore it. Every code turns back into the real name, ID number or email, and the formatting is kept.
Formats
Whatever your AI gives back, with your real data
Anonymizer restores Excel, Word, PowerPoint, CSV and text files: the body, tables, notes, comments and even Office charts. Everything the AI added, formulas, formatting or design, is kept.
- Excel
- Word
- PowerPoint
- CSV
- Text and Markdown
- JSON · HTML
Want charts? A PDF or a chart delivered as an image cannot be restored. Ask for the charts inside an Excel, Word or PowerPoint file and they will update with the real names.
Ideas
What to ask your AI
Ready-to-copy prompts. When you copy one, we add the sentence asking the AI to keep the codes intact, so you can restore its answer afterwards.
Compare this year's sales with last year's by product and by month. Point out what is growing, what is falling and the likely reasons.
Find which active customers are at risk of leaving (buying less, rating lower or having had issues) and suggest a specific action for each one.
Run an RFM analysis (recency, frequency and monetary value) and group customers into named segments with a strategy for each segment.
Which acquisition channel brings customers who spend more and stay longer? Calculate the average customer value per channel.
Suggest 3 Christmas campaigns based on what these customers bought last year and say which customers each one should target.
Analyse incidents and returns: which products, months and customers account for most of the problems.
Calculate monthly recurring revenue, the churn rate per plan and a sales forecast for the next 6 months.
List the returned direct debits per customer, sort them by outstanding amount and draft a friendly reminder email for each one.
Give me back an Excel file with one sheet per customer segment and Excel charts showing how their purchases have evolved.
Prepare a 6-slide PowerPoint presentation with the conclusions for the management committee.
Using this staff list, analyse turnover by department and length of service, without drawing conclusions about specific people.
Want to try it without using your own data? Download the sample spreadsheet: 150 customers and almost 2,000 made-up orders from an online coffee subscription shop.
Download the sample spreadsheetSecurity
Designed so you don't have to take our word for it
Everything happens on your computer
The application sends nothing. It only checks mkfactory.com for a new version, and you can turn that off. It works offline.
Encrypted key file
The mapping between codes and real data is stored encrypted, protected by your Windows user or a password. Without it, the codes mean nothing.
Signed by MKFactory
The installer and the application carry the digital signature of MKFactory Soluciones Digitales, S.L., and every update is verified before it is installed.
Free, no sign-up
It's free: no accounts, no subscriptions, no data in the cloud. Download it, install it without admin rights and get started.
A legal note
Technically this is pseudonymization: as long as the key file exists, the data can be recovered and the GDPR still treats it as personal data. Anonymizer greatly reduces what you share, but it doesn't replace your data protection obligations. Take special care with health data and other special categories, and remember that dates, amounts or postcodes combined can also identify a person.
FAQ
What people usually ask us
Is Anonymizer an AI, or does it connect to one?
No. Anonymizer doesn't include any AI or connect to one: it prepares your files and restores them, all on your computer. You decide which AI (ChatGPT, Claude, Gemini, Copilot…) to upload the anonymized copy to and what to ask it.
Which data does it detect?
Names and surnames, Spanish ID numbers (DNI and NIE), emails, phone numbers, IBANs, addresses and passwords, by their content or by the column name. It's a suggestion: you decide which columns get hidden.
What if I lose the key file?
The codes can no longer be turned back into real data: that is exactly what makes the system safe. Keep it with your files and, if you need it on another computer, protect it with a password.
Can I restore a PDF or an image?
No. In a PDF or an image the text is drawn in place and can't be changed without breaking the layout. Ask your AI for the result in Word, PowerPoint, Excel or text.
Do I need to install anything else?
No. The installer includes everything it needs, doesn't ask for admin rights and the application updates itself when a new version is out. It runs on 64-bit Windows 10 and 11.
Start using AI with peace of mind
Download it, open a customer spreadsheet and in a minute you'll have a copy ready for your AI.