Why is the .ods file size bigger than .xls/xlsx?

[mattqmello]

I like LibreOffice v4.2.8 (pt-BR on Linux). It is a good alternative for MS Office.

But whenever I save a spreadsheet as .ods, and then save the same spreadsheet as .xls/xlsx, the difference between these two files is very big. The same spreadsheet as ODS is 4,5x bigger than itself as XLS:

• spreadsheet.ods (31,7kb);
• spreadsheet.xls (7kb);

Why is LibreOffice ODS format so big?

[Edit]
I read the answer with the doc/docx/odt comparison, that by the way, it’s a great research.

Therefore, I can conclude:

After all, using ODS format, rather than XLS (saved as LO) is not feasible, knowing that it will take up more space on my HDD (31,7KB as ODS vs 7KB as XLS)… Isn’t it?

[mariosv]

About what sizes are you talking about?

[mariosv]

Please take a look in:

Why are LO documents so large compared with MS Word?

I note when I have written a document and saved it in both LO (.odt) and Word (.doc or .docx), the LO document is typically twice as large as the Word document. Why is this? I thought the open document format was supposed to be more compact that the Office format.

[lapo]

I had the same doubt and analyzed both files uzing 7-zip and turns out the main reason is that the ODS file contains a thumbnail image whose size has basic size which dominates the size of a very small file. (but will be washed out by bigger and bigger files)

$ 7z l test.xlsx
   Date      Time    Attr         Size   Compressed  Name
------------------- ----- ------------ ------------  ------------------------
2017-10-12 12:15:34 .....          571          224  _rels/.rels
2017-10-12 12:15:34 .....          382          237  docProps/app.xml
2017-10-12 12:15:34 .....          662          350  docProps/core.xml
2017-10-12 12:15:34 .....          560          224  xl/sharedStrings.xml
2017-10-12 12:15:34 .....          549          210  xl/_rels/workbook.xml.rels
2017-10-12 12:15:34 .....        12013         1973  xl/worksheets/sheet1.xml
2017-10-12 12:15:34 .....         6432          782  xl/styles.xml
2017-10-12 12:15:34 .....          880          507  xl/workbook.xml
2017-10-12 12:15:34 .....         1111          308  [Content_Types].xml
------------------- ----- ------------ ------------  ------------------------
2017-10-12 12:15:34              23160         4815  9 files

versus

$ 7z l test.ods 
   Date      Time    Attr         Size   Compressed  Name
------------------- ----- ------------ ------------  ------------------------
2017-10-12 12:19:22 .....           46           46  mimetype
2017-10-12 12:19:22 .....        13784        13784  Thumbnails/thumbnail.png
2017-10-12 12:19:22 .....         7745         1027  settings.xml
2017-10-12 12:19:22 .....          899          261  manifest.rdf
2017-10-12 12:19:22 .....        33729         2546  content.xml
2017-10-12 12:19:22 .....        26116         2918  styles.xml
2017-10-12 12:19:22 .....          832          412  meta.xml
2017-10-12 12:19:22 .....          985          274  META-INF/manifest.xml
------------------- ----- ------------ ------------  ------------------------
2017-10-12 12:19:22              84136        21268  8 files, 9 folders