Hello Kendo UI team,

We are using Kendo UI for jQuery Spreadsheet and have encountered a border rendering issue that can be reproduced with a very simple setup and no custom configuration.

Reproduction steps

1. Initialize a basic Spreadsheet with default options.

2. Select the range A1:C3.

3. Apply borders to the selected cells (for example, all borders).

4. Select row 3 and delete the row.

Actual result

After deleting row 3:

• The top border of cell B1 disappears.

• Other borders remain unchanged.

• The final border state becomes visually inconsistent and unexpected.

The attached screenshots (step1 → step4) show the full process and the resulting issue.

Expected result

• Borders explicitly applied by the user should remain intact.

• Deleting row 3 should not affect the top border of B1, since that cell is not part of the deleted row.

Request

Is there any solution or workaround for this behavior?

Thank you very much for providing such a powerful and well-designed UI library. We really appreciate the work behind Kendo UI and would love to continue using the Spreadsheet component.

Hello Kendo UI team,

We are using Kendo UI for jQuery Spreadsheet and have encountered a border rendering issue that can be reproduced with a very simple setup and no custom configuration.

Reproduction steps

1. Initialize a basic Spreadsheet with default options.

2. Select the range A1:C3.

3. Apply borders to the selected cells (for example, all borders).

4. Select row 3 and delete the row.

Actual result

After deleting row 3:

• The top border of cell B1 disappears.

• Other borders remain unchanged.

• The final border state becomes visually inconsistent and unexpected.

The attached screenshots (step1 → step4) show the full process and the resulting issue.

Expected result

• Borders explicitly applied by the user should remain intact.

• Deleting row 3 should not affect the top border of B1, since that cell is not part of the deleted row.

Request

Is there any solution or workaround for this behavior?

Thank you very much for providing such a powerful and well-designed UI library. We really appreciate the work behind Kendo UI and would love to continue using the Spreadsheet component.

In the latest version 2025.3.825, the render function doesn't fire after the spreadsheet is rendered.

See this dojo as an example: https://dojo.telerik.com/FQeIFBMD

Right-clicking a spreadsheet column, it is possible to Hide the column.

However, how can the column be unhidden?

Using scroll tabs arrows causes page reload on spreadsheet. This is the two arrows at the bottom right on the spreadsheet control when tabs go off the screen.

This only seems to happen when the spreadsheet is between <form></form> elements. Take these out and it works as expected.

See this dojo: https://dojo.telerik.com/HXscWjdD/2

Did a setting change? This did not happen in earlier versions.

I have a kendospreadsheet with a column filter on every column.

After the user has set filters, I want only to get visible rows.

How is this possible?

Found resources:

https://docs.telerik.com/kendo-ui/knowledge-base/spreadsheet-hidden-rows-count-on-filtering

Using KendoUI latest version, the exportToExcel function in Spreadsheet seems broken.

• Using version 2024.4.1112
• Dojo to reproduce: https://dojo.telerik.com/BMBegbqh (Dojo was linked in docs at https://docs.telerik.com/kendo-ui/api/javascript/ui/spreadsheet/methods/saveasexcel)

Console shows error:

Hi, complicated question regarding the dynamic sizing of JSON data blocks into dataSources inserted into a spreadsheet.

I was getting large dataSources (blocks of data in JSON format) from our responses from API requests, so I bumped up the global row and column sizes for the spreadsheet component:


Problem solved!!! However, I found that this change significantly decreases the performance of imports into the spreadsheet control:

$("#spreadsheet").kendoSpreadsheet({
  rows: 300,
  columns: 20000
});

A little research confirmed this problem with importing an excel spreadsheet into the Kendo spreadsheet component:

Memory Usage:
Initializing with a large dataset consumes a lot of memory. When you import an Excel file, the spreadsheet control needs additional memory to process and render the imported data. This can lead to memory exhaustion and slow performance.


Rendering Overhead:
The spreadsheet control has to render all the rows and columns, even if they are empty. This increases the rendering overhead, making the control less responsive when importing data.


Data Processing:
Importing an Excel file involves:

(1) parsing the file,

(2) converting it to the spreadsheet's internal format

(3) And then rendering it.

With a large number of pre-initialized rows and columns, this process becomes more complex and time-consuming.

Garbage Collection:
The large initial dataset can lead to frequent garbage collection cycles, which can further slowdown the import process. Garbage collection is triggered more often to manage the high memory usage, impacting overall performance. (this is where I noticed frequent garbage collection calls in the browser's Dev Tool Performance page) ...there is probably other stuff hampering the import also as mentioned above.

$("#spreadsheet").kendoSpreadsheet({
 //No explicit settings for rows or columns. Default at 200 rows, and 50 columns.
});

Another workaround found on CoPilot suggested doing this on declaration and initialization of the spreadsheet component:

  // Initialize with a smaller dataset
$("#spreadsheet").kendoSpreadsheet({
  sheets: [{
      name: "Sheet1",
      rows: 100,
      columns: 50
  }]
});

But here is what happens when I do that:

I have better results with this:
SIZE INIT. KENDO SPREADSHEET | Kendo UI Dojo

But there is space below the rows for some reason....that's ok but I know somebody won't like it. :)

So no to the latter approach, and even with an additional resize the grid does not render; the rows and columns do not appear, and the creator and user is stuck with that little blue line.

My workaround was to use the default size of 200 rows and 50 columns.... which significantly improves the loading time of the Excel spreadsheet. This also allows the excel importer topreserve the size of the spreadsheet even if it exceeds the global rows and columns configuration options.

However, when I try to receive an API response message and put it into a kendo dataSource then insert that dataSource into a sheet within the sheet's settings/configurations option:

spreadsheet.fromJSON({
   sheets: [{ name: data.reportName, rows: 19000, column: 65, dataSource: { data: data.MyJsonData, schema: { model: reportModel } } }] //initialize the sheet property with the first report sheet.
            });

The global rows and columns size will override the dataSource size and cut it off at a maximum of 200 rows and 50 columns. hmmm.

(Q) The question is ... how to handle the dynamic sizing of incoming JSON blocks correctly so that the:
 (1)  Initialized first empty grid renders properly (not a problem if you don't initialize an initial sheet with rows and columns).
 (2) The default global values for row and columns are overridden when you insert the sheet coming from the API.

(?)

QUESTION: What is the recommended way of handling this? I have no control or say whether the user can exceed the limit of the default rows and columns configuration options.