As far as exports go - I’d rather export CSV. Lighter, smaller, no formatting applied. Answer from jdsmn21 on reddit.com
Canva
canva.com › home › sheets › xlsx viewer
Free XLSX viewer: Open and view XLSX files online | Canva
An XLSX viewer is an application or tool used to open and view Microsoft Excel spreadsheets that have the .xlsx extension. It lets you see the data in the Excel file without having to download the full program on your device.
Adobe
adobe.com › uk › acrobat › resources › document-files › spreadsheet-files › xlsx.html
How to open, read and edit an .XLSX file
XLSX files are a zipped, XML-based excel file format created by Microsoft Excel. Discover how to open, create, read and edit .XLSX files with Adobe.
How does an xlsx file work?
If you want to go manual way and dont need the styling, use CSV (comma separated values). It's both human readable in raw form and easily parseable/createable. Xlsx is a zip archive that contains XML files. Look for libraries for your language of choice. More than likely, they are already implemented. More on reddit.com
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February 18, 2023What are the disadvantages of .xls files vs .xlsx?
u/eastawat - 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
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March 22, 2022What is an XLSX file? - News - ONLYOFFICE Community
Originally published at: What is an XLSX file? | ONLYOFFICE Blog XLSX is one of the most widely used formats for spreadsheets and is used by a variety of software applications to organize, analyze and store data. Read this guide to know what an XLSX file is and how to create, edit and convert ... More on community.onlyoffice.com
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March 25, 2024How to open .xlsx file directly with Excel WEB, on PC that doesn't have Excel installed?
u/Super_Govedo - 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
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August 3, 2025What is an XLSX viewer?
An XLSX viewer is an application or tool used to open and view Microsoft Excel spreadsheets that have the .xlsx extension. It lets you see the data in the Excel file without having to download the full program on your device.
canva.com
canva.com › home › sheets › xlsx viewer
Free XLSX viewer: Open and view XLSX files online | Canva
Which XLSX viewers convert spreadsheets to PDF?
When you view your file using our XLSX reader, you can export it as a PDF file.
canva.com
canva.com › home › sheets › xlsx viewer
Free XLSX viewer: Open and view XLSX files online | Canva
Are there free XLSX viewers online?
Yes, there are free XLSX viewers online. Our tool is one of the many apps that offer free viewing. Not only that, but you also have access to full spreadsheet functionality. Edit your file and add more data. Invite your team to collaborate on any device.
canva.com
canva.com › home › sheets › xlsx viewer
Free XLSX viewer: Open and view XLSX files online | Canva
Videos
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How to Open XLSX File on Windows - YouTube
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Excel file types CSV vs XLSX vs XLSM - YouTube
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03:04
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01:13
How to Change an Excel File Format to XLSX (Step-by-Step Guide) ...
Google Play
play.google.com › store › apps › details
Xlsx File Reader & Xls Viewer - Apps on Google Play
This Xls File Viewer: Xlsx App was created with the average user and professional in mind. Xlsx Reader: Xls Viewer can access data charts, perform analysis, and manage key Excel file details. The Xls File Viewer: Xlsx App simplifies file handling to a single tap so you focus on your projects instead of fiddling with devices.
Microsoft Excel
excel.cloud.microsoft
Edit spreadsheets online for free | Microsoft Excel for the Web
Create and edit spreadsheets online with Microsoft Excel for the web. Easy formatting, analysis, and real-time collaboration from any device.
Microsoft Learn
learn.microsoft.com › en-us › openspecs › office_standards › ms-xlsx › 2c5dee00-eff2-4b22-92b6-0738acd4475e
[MS-XLSX]: Excel (.xlsx) Extensions to the Office Open XML SpreadsheetML File Format | Microsoft Learn
Specifies the Excel (.xlsx) Extensions to the Office Open XML SpreadsheetML File Format, which are extensions to the Office
Reddit
reddit.com › r/computerscience › how does an xlsx file work?
r/computerscience on Reddit: How does an xlsx file work?
February 18, 2023 -
I have a file that should be structurally very similar to an excel spreadsheet. I want to create a mobile app to read that file, i do not intend to do this to sell it, just for person use (i would use it for work). I tried opening the file with different softwares, but they can just show me the binary and obviously that is no help. If i try to open it with a python algorithm it just returns an error on a byte (unable to decode). The software this file generates is obviously programmed in microsoft visual c++, so i am assuming the file has the same structure as an xlsx file (also because the software works a lot like excel), but online i can't find anything about how excel saves its data in the file. So my question is, how is the structure of an excel spreadsheet? Even if you can give me resources to read from, that would be very appreciated. Thanks in advance
Top answer 1 of 3
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If you want to go manual way and dont need the styling, use CSV (comma separated values). It's both human readable in raw form and easily parseable/createable. Xlsx is a zip archive that contains XML files. Look for libraries for your language of choice. More than likely, they are already implemented.
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As mentioned use, a simple csv file will do for reading in and writing out the data while not being manipulated. You will need to put thought in to the design of your matrix data structure. Personally, I’d use a hash table of hash tables for the in memory representation. Ironically, the first coding challenge of my in person interview at Amazon was to implement a basic spreadsheet program, with constraints on column naming and the ability to do cross cell calculations.
Google Play
play.google.com › store › apps › details
XLSX Viewer: XLS Reader - Apps on Google Play
XLSX Viewer: XLS Reader & Spreadsheets Editor app with XLSX file reader can be your default All-in-1 XLS App and directly open the XLS / CSV / XLSX / XLSM / Sheets from the file manager, email container, or web in this XLS sheet reader without opening the application.
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.
Reddit
reddit.com › r/excel › what are the disadvantages of .xls files vs .xlsx?
r/excel on Reddit: What are the disadvantages of .xls files vs .xlsx?
March 22, 2022 -
The company that provides my database software has, in a bizarre move, removed the ability to export data to .xlsx files, allowing only .xls instead.
I'm making a complaint to them, but I feel like my complaint would carry more weight with some specifics about the problems with .xls files... I'd appreciate if anyone could give me some good reasons why .xls is inadequate!
What I know of the differences so far are:
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the much smaller row and column limits in xls files
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xls files can contain macros, so I guess they're a security risk
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xls files seem to take up at least 50% more disk space
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A couple of colleagues reckon that it takes much longer to export xls files - this makes sense I suppose if the files are larger, but is there another reason for it?
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(this one is presumably specific to my database provider) The xls exports have text qualifiers (') in every non-numeric field. Fields that should be recognised as boolean display as text. So far, macros that read the boolean value in those cells still work, and "=IF(A2,1,0)" still works, but "=IF(A2=TRUE,1,0) does NOT work.
Any further insight would be greatly appreciated!
PS this is probably a bit different from the usual posts on this sub, I hope I've complied with the rules!
Edit: I now realise I probably should have tagged this as a discussion, as there isn't really a solution per se. Might leave it open for a while longer in case there are any other interesting comments or suggestions before I mark one lucky commenter with "Solution verified", in the meantime, thanks to everyone for your insight and knowledge :)
Edit 2: thanks to the mod who changed the tag to discussion!
Top answer 1 of 14
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As far as exports go - I’d rather export CSV. Lighter, smaller, no formatting applied.
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One recent example of why the XLS-format can cause trouble: http://www.eusprig.org/horror-stories.htm item POB2001 Why using Microsoft's tool caused Covid-19 results to be lost "The badly thought-out use of Microsoft's Excel software was the reason nearly 16,000 coronavirus cases went unreported in England. [The labs] filed their [result logs] results in the form of text-based lists - known as CSV files - without issue. PHE had set up an automatic process to pull this data together into Excel templates so that it could then be uploaded to a central system. The problem is that [Public Health England] PHE's own developers picked an old file format to do this - known as XLS. As a consequence, each template could handle only about 65,000 rows of data rather than the one million-plus rows that Excel is actually capable of. And since each test result created several rows of data, in practice it meant that each template was limited to about 1,400 cases. When that total was reached, further cases were simply left off. To handle the problem, PHE is now breaking down the test result data into smaller batches to create a larger number of Excel templates."
App Store
apps.apple.com › us › app › xlsx-sheets-edit-spreadsheet › id1672553988
XLSX Sheets: Edit Spreadsheet App - App Store
New improved features are now live - - Read, and edit any spreadsheet, xls, or xlsx files. - Compatible with excel formats like - xls, xlsx, csv, xlsm, etc. - Analyse and calculate formulas on the go, even offline. - Convert your sheets to PDF and share easily.
ONLYOFFICE Community
community.onlyoffice.com › news
What is an XLSX file? - News - ONLYOFFICE Community
March 25, 2024 - Originally published at: What is an XLSX file? | ONLYOFFICE Blog XLSX is one of the most widely used formats for spreadsheets and is used by a variety of software applications to organize, analyze and store data. Read this guide to know what an XLSX file is and how to create, edit and convert ...
data.europa.eu
data.europa.eu › apps › data-visualisation-guide › excel-files
Excel files
Probably even more popular for exchanging data than CSV files, are spreadsheet files, of which Excel files are the most used. These files have an .xlsx extension (older files can have an .xls extension, and when a file contains macro’s, the extension is .xlsm).
Jumpshare
jumpshare.com › viewer › xlsx
XLSX Viewer - Open XLSX File Online for Free | Jumpshare
By sharing your files or using our service, you agree to our Terms of Service and Privacy Policy. View Microsoft Excel Document (.xls, and .xlsx) files online without the hassle of installing any software or signing up for an account.
Cdlib
uc3.cdlib.org › 2012 › 02 › 16 › whats-the-deal-with-xlsx
What’s the Deal with .xlsx? – UC3 California Digital Library
February 16, 2012 - The additional “x” in Excel file extensions stands for XML. XML is Extensible Markup Language, which is a markup language useful for data, databases, and data-related applications. The file type .xlsx is a combination of XML architecture and ZIP compression for size reduction.
CloudConvert
cloudconvert.com › xlsx-converter
XLSX Converter | CloudConvert
XLSX is a proprietary spreadsheet file of Microsoft Excel that contains data. It contains data in rows or columns as well as charts. XLSX supports several mathematical functions also. It uses Open XML standard for containing data.
Microsoft Store
apps.microsoft.com › detail › 9n4jh8ngjr9b
XLSX Spreadsheet - Free download and install on Windows | Microsoft Store
May 29, 2026 - Files in the following formats can be viewed and converted to the Sheets format/Excel format: .xls (if newer than Office 95), .xlsx, .xlsm, .xlt, .xltx, .xltm .ods, .csv, .tsv, .txt and .tab Free Version: + View and Basic Edit Excel format files ...
ONLYOFFICE
onlyoffice.com › blog › 2024 › 03 › xls-vs-xlsx
XLS vs XLSX: differences and ways to convert between | ONLYOFFICE Blog
March 29, 2024 - Although XLS files have served as a standard for Excel for many years, they have limitations on the amount of data and compatibility with newer Excel versions and other spreadsheet programs. XLSX (Excel Open XML Spreadsheet) is a new file format ...
Reddit
reddit.com › r/excel › how to open .xlsx file directly with excel web, on pc that doesn't have excel installed?
r/excel on Reddit: How to open .xlsx file directly with Excel WEB, on PC that doesn't have Excel installed?
August 3, 2025 -
So company upgraded to Window 10 Server, and we don't have Office installed anymore. We are forced to WEB apps now.
I have bunch of Excel files on Desktop and I don't want them accessed only through OneDrive folder.
Is there a way to somehow link .xlsx extension to Excel WEB? As well as Word extension.
File Examples
file-examples.com › home › sample documents download › sample .xls and xlsx download
Sample .xls and xlsx download | File Examples Download
March 19, 2018 - Microsoft Excel worksheet sheet (97–2003) · The .xls format is native to Microsoft Excel. This is a file extension for a spreadsheet file format. .xls files can also be opened and edited by the Microsoft Excel Viewer, and OpenOffice
ONLYOFFICE
onlyoffice.com › blog › 2024 › 03 › xlsx
What is an XLSX file? | ONLYOFFICE Blog
March 25, 2024 - In a nutshell, an XLSX file is a zipped archive which contains a set of XML files. Each XML file represents one of the components of a spreadsheet. For example, the workbook, sheets and cells.