So if Microsoft Word uses .docx (formerly .doc), what 'format' is a Google document in?

How does it all work?

Does it just use the HTML standard to make up the document on the page you're working on? (And if so what HTML revision is it using - at least currently?)

  • 2
    I can't remember why I said 'currently' - but either way I guess the answer should always pertain to 'as of now' and be always updated where possible.
    – user23222
    Jun 6, 2014 at 7:45
  • The Google Docs format is described here: developers.google.com/docs/api/concepts/structure Apr 24, 2020 at 20:12

2 Answers 2


Google uses a proprietary format called “kix”, which was introduced with the then new editor a few years ago. The basic structure of a kix file isn't comparable to structured markup (like docx which is basically a zipped collection of XML files holding content and styles) but rather like a data file which starts with the textual content followed by styling information delimited by ASCII control codes.

What you see in your editor is the HTML-rendered content provided by the underlying JavaScript. If you want to work with the document in another application you are able to access the files via the Google Drive API, as John already pointed you to. Although it’s technically possible yet undocumented to export the kix file, this is due to the proprietary format of not so much use.

  • 4
    Good stuff, but can you cite a source?
    – ale
    Jul 19, 2014 at 16:41
  • 10
    That's based on my own discoveries while working with the Drive API. You can explore the kix format of any Google Document while being logged in with this link https://docs.google.com/feeds/download/documents/export/Export?id=[your document's id goes here]&exportFormat=kix Jul 19, 2014 at 17:42
  • Fantastic knowledge, thank you for sharing your information! :D
    – user23222
    Jul 19, 2014 at 21:39
  • Is it still possible to download a file in kix format in 2018?
    – Foobar
    Nov 26, 2018 at 22:03
  • We can cite source now: webapps.stackexchange.com/a/65548/77116 :-)
    – Mars
    Jan 15 at 22:25

Google hasn't made it publicly known what format they store Google Docs in at this time. The closest I can find to anything official is this post:

We do not expose our native formats at this time

Google Docs supports importing and exporting in a range of formats (including docx, odt, pdf and html), however they convert going each way to their internal format.

The Google Docs editor does use HTML and is driven by Javascript, you can read about it in this blog post.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.