When you convert Excel spreadsheets for the web, your formulas become visible in the program code. If you need to protect your Excel formulas, use the industry-standard, open source Node.js environment to hide the formulas on the web server.

When an Excel spreadsheet is converted for the web, the formulas in the spreadsheet are converted to program code. This program code is clear-text and any reasonably skilled programmer can read the program code and extract crucial information like markup or discount levels, salary information or date/time-related parameters. When a calculator is for internal use only, this is usually not a problem, but when you expose your business algorithms to the general public it means someone can learn a lot about your business with very little effort.


Protect your Excel formulas with Node.js

To provide a secure operating environment for business-critical calculations, the Node.js flavor of SpreadsheetConverter creates the program code separately from the web page. When a website visitor wants to use the calculator, the web browser downloads the web page from the web server without any sensitive program code. Instead, special code snippets in the web page act as conduits between the web page and the program code on the Node.js server. This effectively hides the spreadsheet’s formulas and their program counterparts from any prying eyes.

We converted this spreadsheet for Node.js and uploaded the calculator to one of our own Node.js servers. Click on the image to see the results.

Screenshot of the Equity Analysis example for Node.js

As you can see, Node.js requires no extra learning for end users. The web page looks just like they are used to. There is no noticeable difference in behavior or speed.

Protecting your investment

Photo of an engineer studying a project plan on an iPad tablet

Many spreadsheets contain business-critical information. In the wrong hands, the same information can be used to create extensive damage to your business.

In our server-based flavors like Node.js, the formulas are executed directly on the web server, which makes them inaccessible to intruders. You can calculate your markups, interests or salary increases knowing that no-one can access the formulas or their values on the server.

Online spreadsheets make your web professional

A time-saving calculator makes your web site stand out from the competition. It’s so easy to put any existing form or calculator on the web: expense reports, surveys, quote generators, order forms, reservation forms, employment applications, financial calculators, engineering tools – the list is endless.

We’re not only talking simple plus-and-minus spreadsheets here.

  • Create mobile-friendly, responsive forms that automatically adapt to different screen widths, portrait/landscape orientation etc.
  • To make it easier to understand a large form, split it into two or more separate steps and let users navigate between the sections using tabs, next/previous buttons or sliding panels.
  • Use graphical widgets like menus and calendars to make the form easier to use.
  • Hide rows or complete sections of a form until you know they are applicable.
  • Allow file attachments with submitted web forms.
  • You can have mandatory responses.
  • Use hidden fields to discretely include supplemental information in the form.
  • With Real-time Sync, two or more persons can share a web form and collaborate in real-time.
  • Fetch live data from corporate databases when run on ASP.Net or Node.js servers.
  • Build forms-based web apps for iPhone and Android devices that can submit smart forms directly  – even when the phone is offline.
  • Use live, interactive charts that invite users to point-and-click, and the charts automatically update when values are changed.

The free form-to-Inbox service requires no installation, no programming skills and no configuration. Once you upload your first web form to your server, submitted forms start arriving at your Inbox. You are up and running within minutes. For a small monthly fee, we can store submitted forms in a cloud database for you until you visit our server to pick them up.

Features and benefits

SpreadsheetConverter is the perfect tool for creating calculating web forms and web pages that attract attention.

  • The formulas are protected: All calculations are done on the server, so your formulas are totally hidden from the user.
  • It’s easy even for non-programmers: SpreadsheetConverter turns your business users’ Microsoft Excel spreadsheets into fast and scalable Node.js applications.
  • It runs on almost any web server. The Node.js environment runs in most standard web server environments including Windows, Macintosh OS X and Unix.
  • You can easily protect your calculators and web forms behind a login. You manage the user list yourself and there’s nothing extra to install on the server except for the converted web page.
  • It’s so easy to change: Just change the spreadsheet and re-run the conversion to regenerate the Node.js server code.
  • Everything is live and interacting with your visitors: The calculator or form updates dynamically when values are changed. Even the charts are live! Use calendars to select dates, stars to set ratings and sliders to vary data in real-time. Create forms with dropdown menus, checkboxes, radio buttons, large text fields, list boxes in a breeze. Design step-by-step wizards for complex forms.
  • It looks so good on the web: Normally, it takes a lot of time to make a web page look this well-designed. With Excel you just format the page the way you like. SpreadsheetConverter creates a web page that looks the same: borders, colors, fonts, checkboxes, dropdown lists etc work as they should, and numbers are formatted on the fly with decimals, thousand separators and currency symbols. Play with new layouts inside Excel before you convert them to web format, which saves lots of time (besides being lots of fun). Use graphical themes to give all your calculators a common look.
  • Work together across the web: users can share a calculating webpage with colleagues, and work together with them in real-time on laptops, tablets and smartphones.
  • Integrate with other systems using barcodes, e-mail and http.

Photo of a laptop with a calculator in Excel , and a tablet where the same calculator is shown in a web browser

Photo of a couple in a cafe, using a calculator converted from Excel

  • Looks great on any device: smart responsive design automatically reformats the calculator so that it looks great on any screen size.
  • The Link Image widget allows you to show different images in the web page depending on cell values or formulas. Now you can build advanced imaging applications where an image on the screen changes with the values in a web form or calculator.
  • Automatic form-to-Inbox delivery: When users submit completed forms, SpreadsheetConverter delivers them directly to your e-mail Inbox. For a small fee, forms can be saved in a database for later retrieval, thanks to a hosted service that requires no local installation or server.
  • Users can include up to ten files with any form they submit. Job applicants can include their CV, and expense reports can include scanned copies of receipts.
  • You get the source code: The JavaScript server code is nicely formatted and completely self-contained. There are no library files or other external requirements.
  • There are no errors: The calculator doesn’t need any testing, since thousands of users already have tested our calculation engine.
  • It’s cost-effective: You need the SpreadsheetConverter program only when you perform the actual conversion from spreadsheet to web page format. You need one license for each PC on which you install the program to perform such conversions.
  • Excel isn’t needed: Once the web page is created, Excel is not required. Your web server doesn’t need Excel, and your users don’t need Excel. Even if Excel is all around, not all employees have it, and private persons seldom have it.
  • It’s free to distribute: With the Professional Edition, you can make the calculator part of a product that you sell.
  • You take no risk: Every purchase comes with a 30-day money-back guarantee and six months of free e-mail support.

SpreadsheetConverter makes business users more productive

  • Use your existing skills. If you can do it in Excel, you can now put it on the web.
  • Everybody’s using the latest version. No more old prices or discounts in old spreadsheets.
  • You can hide your formulas with our server flavors.
  • It’s lightning fast. Your spreadsheet formulas are converted to small, fast scripts that run in the user’s web browser.

And there’s more:

  • You don’t need a programmer. You don’t get live, calculating web pages like these for free from your web design company. Here you do all the work yourself, in Excel and with the converter, and you still get higher quality and performance – we’ve done this so many times before.
  • It’s very easy to change: Business is changing all the time. New prices, new discount structures, new regulations. With hand-crafted web pages it’s hard to keep up with the frequent changes – and you have to pay the programmer every time. With SpreadsheetConverter, you just change your spreadsheet and update the web page.
  • It supports almost all Excel’s built-in functions. You can do some pretty advanced calculations in your web page. All but a few advanced financial and statistical functions are supported.

Fast, stable and secure

Live, calculating web pages like these are very expensive to develop by hand with all the programming, testing and debugging that takes a lot of time even for a specialist.

By developing your expense report, order form or shipping calculator in Excel, you save a lot of time already at the design stage. Your calculator works and can be tested even before we turn it into a web page for you.

The converter turns the spreadsheet formulas into blocks of standard program code that have been meticulously tested by thousands of users.

The web pages are responsive and adapt to the screen width. On the narrow screen of the tablet, there is only room for two blocks side-by-side.


Our selection of flavors

  • Our basic product converts Excel spreadsheets to HTML with embedded JavaScript that can be used with any web server. All calculations are performed in the browser, without any help from the web server.
  • SpreadsheetConverter can also generate HTML5 web apps for iPhone and Android smartphones. These make it easy to collect data with mobile devices, select or configure products or do spreadsheet calculations in a smartphone. Web apps can be delivered through an app store and you can charge for them.
  • Special server products generate program code for Node.js, web servers. Since this flavor keep the formulas on the server and perform all calculations there, your business formulas are hidden from the end user. Running the formulas on the server also makes it much easier to add back-end integration, for example for saving and restoring values to a database. Communication with the server is minimal and the web calculator updates itself quietly in the background while the user is busy entering data into the next cell. Your technical people refer to this technology AJAX.

Superior support

If you need help, don’t hesitate to contact our Help Desk. We guarantee free of-course-we’ll-get-you-up-and-running support during your free trial and for at least six months after you purchase a license. Expect an answer by the next business day, often within the hour.

We first released SpreadsheetConverter in 2002, and have added more and more value to the product in many releases since then. Our update policy gives you free updates within the same major version, e.g. if you have a version 10 license you get all version 10.x updates for free.

We have three support centers in Europe, America and Asia that provide almost around-the-clock support during workdays. Technically competent support engineers will answer your e-mails and solve your problem. Most of them are programmers or web developers with long experience.

With any error report, we beg you to include the spreadsheet that’s causing you problems. Yes, we know they often contain terribly important information, but we need to recreate your problem in order to solve it, and it may be so difficult unless we have exactly the same data as you have.

If you buy a license, and we happen to release a new version within six months after your purchase, we’re not greedy – we’ll automatically give you a complimentary upgrade to the new version free-of-charge.

Low cost, no risk

We recommend that you start with the Standard edition of SpreadsheetConverter HTML to learn the basics. As you become confident in your ability to generate web pages from Excel, you can add more “flavors” – technical publishing environments – to your toolset.

For serious publishing business, the Professional Edition lets you create web pages for clients, supports all the nerdiest Excel functions and provides even more beautiful chart types.

Here is the complete price list:

License to generate HTML pages$254$494
License to generate pages for iPhone/Android$334$654
License to generate pages for Node.js$374$714
Cost per month$0$0
Cost per page$0$0
Cost per server$0$0
Cost per visitor$0$0
* VAT or the equivalent sales tax in your country will be added to the prices above if applicable.

SpreadsheetConverter is an add-in for Microsoft Excel in Windows. It appears as an extra menu in Excel. Excel and SpreadsheetConverter are only used when you create the spreadsheet and convert it to web format. We charge a small one-time license fee for each computer on which you install the Excel add-in to perform such conversions.

  • There are no additional fees per month.
  • There are no additional fees per page or conversion.
  • There are no additional fees per web server, page view or visitor.
  • There are no additional fees for Excel or plug-ins. The web pages we create have everything in them and do not need or use Excel.

In fact, when spreadsheets are available online like this, many people no longer need their own Excel licenses, which can generate additional savings.


There is no risk, you’re safely protected by our 30-day money-back guarantee. If you are not satisfied with your purchase, just send us an e-mail, and we will cancel your purchase and refund the money.


Let us convert a spreadsheet for you, right now!

We’ll gladly convert one of your own spreadsheets for you. It’s so simple to do, we won’t even charge you anything for it. It won’t take us much time anyway.

If you like the result, we hope you’ll want to install the program and take it for a test drive in your own laptop.

E-mail us one of your spreadsheets right now!


Download and try the program for free for 30 days

SpreadsheetConverter is an add-in for Microsoft Excel in Windows. It appears as an extra menu in Excel.

You don’t need a license to test the Excel add-in, just download the trial version and install it on your Windows computer. We recommend that you start with SpreadsheetConverter HTML. If you buy a license for one flavor and later want to upgrade to a different flavor, you only pay the price difference.

SpreadsheetConverter does not collect personal data or show ads. It is easy to remove it completely if you don’t want it.

If you want to preview converted web pages before uploading them to a web server, you will have the option to add an exclusion to the Windows firewall. No other system or browser settings are changed.


Technical requirements

SpreadsheetConverter is an add-in for Microsoft Excel in Windows. If you have a reasonably current version of Excel running in a Windows PC, you’re probably good to go.

For an overview of the various flavors of SpreadsheetConverter and their exact technical requirements, please study the product comparison chart.

Web pages generated by SpreadsheetConverter Node.js require a web server with the free Node.js environment.

Try this Excel add-in now!

Click on Download to install and test this Excel add-in for Windows.

Click on Upload to let us convert a spreadsheet for you for free.