When saving the file you should save it with its extension:

Sub SaveFile()

    savename = Application.GetSaveAsFilename(fileFilter:="Exel Files (*.xlsx), *.xlsx") 
    ActiveWorkbook.SaveAs Filename:=savename, FileFormat:=51 

End Sub
Answer from some_weired_user on Stack Overflow
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Microsoft Support
support.microsoft.com › en-us › excel › saving-xls-to-xlsx-xlsm
Saving xls to xlsx xlsm | Microsoft Support
Open the workbook > Navigate to File > Save As > Browse – which will open the below window. Make sure you are in the right path to save the workbook > Choose Excel Workbook (*.xlsx) under Save as type > Select Save.
Discussions

I want to copy a sheet from an xls file into a xlsx file. Do you know how to do it?
u/Soft_Mulberry5645 - Your post was submitted successfully. Once your problem is solved, reply to the answer(s) saying Solution Verified to close the thread. Follow the submission rules -- particularly 1 and 2. To fix the body, click edit. To fix your title, delete and re-post. Include your Excel version and all other relevant information Failing to follow these steps may result in your post being removed without warning. I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns. More on reddit.com
🌐 r/excel
8
9
February 16, 2024
Looking for VBA Code to save XLS as XLSX (with the original file name) in the users download folder.
To clarify, you want to change the format of ALL the xls files in the Download folder? Sub ExampleCode() Dim fPath As String Dim fName As String Dim strNewName As String Dim wb As Workbook 'Where is the user's download folder? fPath = Environ$("USERPROFILE") & "\Downloads\" 'Prevent screen flicker Application.ScreenUpdating = False 'Find files with specified ending fName = Dir(fPath & "*.xls") Do Until fName = "" Set wb = Workbooks.Open(fPath & fName) strNewName = Replace(wb.Name, ".xls", ".xlsx") wb.SaveAs Filename:=fPath & strNewName, FileFormat:=51 wb.Close 'Get next file fName = Dir() Loop 'Reset Application.ScreenUpdating = True End Sub More on reddit.com
🌐 r/excel
6
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April 11, 2024
Do I need to do "Save as Google Sheets" for .xlsx files? - Google Docs Editors Community
Skip to main content · Google Docs Editors Help · Sign in · Google Help · Help Center · Community · Google Docs Editors · Terms of Service · Submit feedback · Send feedback on More on support.google.com
🌐 support.google.com
May 18, 2023
why can't I save xls file as xlsx?
Save the file using "Save As": Open your .xls file in Excel, and then go to "File" > "Save As". In the "Save as type" dropdown menu, select "Excel Workbook (*.xlsx)". Choose a location to save the file and click "Save". More on learn.microsoft.com
🌐 learn.microsoft.com
1
0
March 21, 2023
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The Bricks
thebricks.com › home › resources › how to save an excel file as xlsx
How to Save an Excel File as XLSX
April 22, 2025 - This is the most critical step. In the "Save As" dialog box, you'll see a field labeled "File name" and right below it, a dropdown menu labeled "Save as type." Click this dropdown to see a list of all available file formats. From the list, select Excel Workbook (*.xlsx).
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Quora
quora.com › How-do-you-save-a-file-as-an-xlsx-file-in-Microsoft-Excel
How to save a file as an .xlsx file in Microsoft Excel - Quora
Answer (1 of 2): First you need Excel 7.0 or later. Before that, there was only .xls format. If you have Excel 7.0 or later, the file save is to .xlsx by default. “By default” means it already set up to save to .xlsx without you doing anything extra special.
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ExcelDemy
exceldemy.com › home › excel basics › how to save the excel file in xlsx format – 4 easy methods
How to Save the Excel File in XLSX Format - 4 Easy Methods - ExcelDemy
August 4, 2024 - In Save as, name the workbook and choose Excel Workbook. Click Save. Your Excel book will be in XLSX format. ... Click “File”. Choose Options to open a new window.
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CustomGuide
customguide.com › course › excel › how-to-save-in-excel
How to Save in Excel | CustomGuide
Click the Save as type list arrow. The default file type is an XLSX Excel file, but you can choose from plenty of other file formats in this menu.
Find elsewhere
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Microsoft Support
support.microsoft.com › en-us › office › save-your-workbook-92e4aae0-452d-497f-a470-570610ff720a
Save your workbook | Microsoft Support
Wherever you want to save your workbook (on your computer or the web, for example), you do all your saving on the File tab. While you'll use Save or press Ctrl+S to save an existing workbook in its current location, you need to use Save As to save your workbook for the first time, in a different location, or to create a copy of your workbook in the same or another location. ... If you are trying to save a macro-enabled workbook (.xlsm) as a regular workbook (.xlsx), be advised that macros will not be saved in the new file, which could result in loss of functionality, as VBA macros are a powerful way to automate significant amounts of work.
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SimpleSheets
simplesheets.co › blog › how-to-save-an-excel-spreadsheet
How to Save an Excel Spreadsheet: 5 Methods - Simple Sheets
March 9, 2025 - Select Save As. Choose where to save the file (e.g., This PC, OneDrive, or a specific folder). Enter a file name that is easy to recognize. Select the file format (default: .xlsx).
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Microsoft Support
support.microsoft.com › en-us › office › save-a-workbook-in-another-file-format-6a16c862-4a36-48f9-a300-c2ca0065286e
Save a workbook in another file format | Microsoft Support
If you opened an Excel 97-2003 workbook but don’t need to keep it in that file format, simply convert it to the current file format (.xlsx). Click File > Info. Click Convert. In Excel 2013, you can open and save files in the following file formats:
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Aspose Pty. Ltd.
tutorials.aspose.com › aspose.cells › .net › saving files in different formats › save xlsx file
Save XLSX File | Aspose.Cells .NET Excel Processing API
May 8, 2026 - Yes, you need a valid license for commercial use, but a free trial is available at Aspose Free Trial . Absolutely! You can load existing XLSX files by passing the file path to the Workbook constructor. If you’re not in a web environment, you can simply save the workbook to a file path without using the HttpResponse.
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Home and Learn
homeandlearn.co.uk › excel2007 › excel2007s1p8.html
How to save your Microsoft Excel spreadsheet
If you're happy to save your work in the My Documents folder, then type a name in the text box that says "Enter file name here". Click the Save button to the right and your file will saved as a XLSX spreadsheet.
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Reddit
reddit.com › r/excel › looking for vba code to save xls as xlsx (with the original file name) in the users download folder.
r/excel on Reddit: Looking for VBA Code to save XLS as XLSX (with the original file name) in the users download folder.
April 11, 2024 -

I have tried a few things but am still very new to VBA. I feel like this should be somewhat simple but all the posts I've looked at haven't been for this exact problem and trying to tweak them hasn't worked either.

Excel version 2403 (Windows 10)

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OmniSecu
omnisecu.com › excel › basics › how-to-change-default-save-file-format-type-xlsx-in-excel.php
How to change default save file format type xlsx in Excel
Home >> Knowledgebase >> Excel >> Basics >> How to change default save file format type xlsx in Excel · The default file type when you save an Excel document file is "xlsx", as shown in below image.
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Google Support
support.google.com › docs › thread › 216425487 › do-i-need-to-do-save-as-google-sheets-for-xlsx-files
Do I need to do "Save as Google Sheets" for .xlsx files? - Google Docs Editors Community
May 18, 2023 - Skip to main content · Google Docs Editors Help · Sign in · Google Help · Help Center · Community · Google Docs Editors · Terms of Service · Submit feedback · Send feedback on
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MrExcel
mrexcel.com › forums › question forums › excel questions
VBA: Save Sheet as xlsx file in original folder and original filename. | MrExcel Message Board
May 3, 2022 - If you want the file name to come from cell N1, you need to specify which worksheet N1 is located on, and the value in N1 must be a legal filename with an ".xlsx" file extension. ... 'Save ActiveSheet to new WB w/ macro-free format while keeping original file open Sub SaveXLSX() Dim Folder As String, FileName As String, FilePath As String, SheetName As String Dim DestWB As Workbook Folder = ThisWorkbook.Path FileName = "MyNewWorkbook.xlsx" 'name of new .xlsx workbook 'FileName = ActiveSheet.Range("N1").Value 'name of new .xlsx found in cell N1 FilePath = Folder & FileName SheetName = ActiveShe
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Apple Community
discussions.apple.com › thread › 255513855
How to save Numbers file as XLSX by defau… - Apple Community
March 6, 2024 - It needs to be exactly as in the menu system, including the ellipsis character. If you are going back and forth from Numbers to Excel, I recommend you get Excel or one of the free Office-like suites. Numbers is able to import and export Excel files but it is not perfect and is not meant to be an Excel clone. ... No. Numbers saves to Numbers, and exports to Excel.
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MacScripter
macscripter.net › scripting forums › applescript | mac os x
Save Excel CSV file as Excel XLSX file - AppleScript | Mac OS X - MacScripter
September 11, 2024 - I had a routine that used to save a CSV file as XLSX now I get a parameter error Excel version V16.88. This is the code that used to work any suggestions please. tell application "Finder" set thefolder to alias "Macintosh HD:Users:petermitchell:Library:CloudStorage:Dropbox:DownloadsSafari:" open last item of (sort (get files of thefolder) by creation date) --The file download from the Web is downloaded in CSV format and offers an option to convert tell application "System Events" tell pr...
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Mescius
developer.mescius.com › spreadnet › docs › latest › online-win › overview › spwin-devguide › spwin-usefiles › spwin-savefiles › spwin-save-excelfile
Saving to an Excel File | Spread Windows Forms
If you do not specify the Exchangeable option, the image cell type won't be saved to XLSX file and Spread will export a shape instead. If you open the exported file in Excel or Spread (with or without Exchangeable option), an empty cell and a shape are displayed. ... The following example saves the spread data along with all the settings to an Excel file using the SaveExcel method which has ExcelSaveFlags options UseOOXMLFormat and Exchangeable as arguments.