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.

See more examples of what SpreadsheetConverter Node.js can do for you.

Free offer: Send us a spreadsheet and we’ll send it back as a web page.

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, we’re talking

  • a responsive calculator design that automatically adapts to both the widest and most narrow screens
  • all the graphical user interface widgets you could ask for, in colorful themes
  • live charts that automatically update when values are changed
  • live team collaboration with worksheets shared over the Internet in real-time
  • step-by-step wizards for complex forms
  • smart table lookup, complex data validation, interactive menus

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 store submitted forms in a 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.
  • 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.
  • Looks great on any device: smart responsive design automatically reformats the calculator so that it looks great on any screen size.
  • Work together across the web: share a calculating webpage with your colleagues, and work together with them in real-time on laptops, tablets and smartphones.
  • 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

  • It’s so easy to change: Business rules frequently change, e.g. new prices, new discount options, new regulations etc. With hand-crafted web pages it’s hard to keep up with the frequent changes. With SpreadsheetConverter, you just change the spreadsheet, and regenerate the web page.
  • The business formulas are securely protected. All calculations are done on the Node.js server.
  • It supports almost all Excel’s built-in functions. Currently all but a few advanced financial and statistical functions are supported.

Fast calculation with prefabricated components

Creating a calculating web page like an expense report or order form online can be very difficult. Programming, testing and debugging takes a lot of time even for a specialist. Most online calculators do all their calculation on the web server, which can make the web page slow because of all the network communication with the server.

With SpreadsheetConverter, all your spreadsheet formulas are automatically converted into program code by SpreadsheetConverter, using prefabricated components that have been meticulously tested. The conversion to web format retains the interactivity that is typical of a spreadsheet, and the entire visual layout is carried over to the web page.

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 applications for iPhone and Android smartphones. This makes it easy to collect data with mobile devices, select or configure products or do spreadsheet calculations in a smartphone.

Special server products generate program code for Node.js, ASP.NET and classic ASP web servers. Since these flavors keep the formulas on the server and perform all calculations there, the 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 another cell.

Superior support

We guarantee top-notch support. Technically competent support engineers are here to answer your e-mails. They are all programmers and web developers. You should get answers by the next business day, often within the hour. Free e-mail support for six months is included with every purchase.

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 8 license you get all version 8.x updates for free.

If you buy a license, and we release a new version within six months, you get 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 most nerdy Excel functions and provides even more beautiful chart types.

Here is the complete price list:

License to generate HTML pages$127$247
License to generate pages for iPhone/Android$167$327
License to generate pages for Node.js$187$357
License to generate pages for ASP.Net$187$357
Cost per page$0$0
Cost per server$0$0
Cost per visitor$0$0

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 program to perform such conversions.

  • 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

You don’t need a license to test the program, 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.

Technical requirements

SpreadsheetConverter normally doesn’t require anything special. 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.

Build live website calculators and web forms now!

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Just download, install and test the Excel add-on now. Or let us convert a spreadsheet for you, for free.