In my recent blog post on Converting Word to PDF or HTML, I described some confusion that stems from Microsoft Word's having two fields, Title and Description, for entering alt text for images. Unbeknownst to me at the time, Greg Kraus of NC State had recently written a similar blog post in which he echoed this confusion.
Prior to Office 2010, Word only had one alt text field, which was simple enough. That's the field you would use to add a brief description of the image, and your description would survive as alt text when the Word doc was exported to tagged PDF or HTML.
But now there are two fields, Title and Description, in all versions of Word from 2010 onward.
Word's Format Picture dialog includes help text that describes Microsoft's intention: "The screen reader first reads the title. The person can then decide whether to hear a longer description."
This isn't a bad idea. It's analogous to the alt and longdesc attributes that have historically been used for different purposes in HTML. All informative images need a short, sweet description in order to provide access to the image content (alt); and some images additionally need a long description where the content is too complex to be described succinctly, for example a chart, graph, or diagram (longdesc).
However, this model can only be effective if it's well supported and properly implemented, and currently it's not. This model has been adopted by other tools, include Google Docs, Open Office, and Libre Office, all of which now have both Title and Description fields for alt text. However, there are variations in how this data is used and whether it survives when exported or imported from one application to another.
So, which field(s) should you use? Answer: It depends...
If your original document is in Microsoft Word
- If you intend to share your document in its original Word format, use Description. In Word 2013, JAWS 15 reads both fields together, each prefaced by "Title:" and "Description:". However, NVDA 2014.2 and Window-Eyes 8.4 both read only the Description, not the Title.
- If you intend to export to tagged PDF via "Save As PDF" in Word for Windows, use Description. Description is passed to the PDF as alt text, and Title is lost.
- If you intend to export to HTML, the two fields are combined into a single alt attribute (using "Title:" followed by the title, then "Description:" followed by the description). This isn't exactly how long description was intended to work in HTML. Nevertheless, you could use both fields but I still recommend just using Description, since it's the only supported field in the previous two scenarios.
- If your Word document might be opened in Open Office, understand that neither Title nor Description survives the import. There's nothing you can do about that.
- If your Word document might be opened in Libre Office, both Title and Description survive the import. For more on what happens with alt text after its been imported into Libre Office, see the Libre Office section below.
- If your Word document might be imported into Google Docs, the Title is imported into Google's Description field, and the original Description is lost. This obviously complicates the situation, and might argue for using Title if Google Docs were the only expected means of distributing your document. However, this is clearly a bug in Google's import feature (it's not a problem when exporting the other direction) so don't let it have too strong an influence on your decision. Google has been notified of the problem and hopefully will fix it soon.
If your original document is in Google Docs
- Using a screen reader with Google Docs is still a bit of a chore, but by painstakingly following Google's help doc Getting started in Google Docs with a screen reader I can successfully read a document with NVDA in Firefox, VoiceOver in Chrome, and ChromeVox in Chrome. In all cases, screen readers read both Title and Description, each prefaced by "Title:" and "Description" respectively. That said, if your audience might include screen reader users, I don't recommend using Google Docs as your final means of distributing the document. Though it might be technically possible to read the document using Google's recommended screen reader and browser combinations, many users will not have discovered Google's screen reader help doc, or had the patience to study and practice its recommendations, and they will find Google Docs to be confusing, cumbersome, and frustrating. Instead, you could use Google Docs for authoring, then export to another format.
- If you intend to export to Word, the recommendations in the previous section apply (use Description: It does survive the export from Google to Word, and in Word it's better supported than Title).
- If you intend to export to HTML, Google's Description field is used for the HTML alt attribute and Google's Title field is used for the HTML title attribute. It's important therefore to understand the difference between these HTML attributes. The alt attribute is specifically intended to be alternative text for people who can't see the image; by default it's the text that's typically ready by screen readers. The title attribute is used to provide supplemental information for all users, and is typically rendered by browsers as a tooltip that appears when mouse users hover over an object. Sometimes screen readers read title, but not always, and typically they don't read it when alt is present.
- If you intend to export to PDF, don't use Google Docs. It creates a PDF that has no tags and is therefore not at all accessible.
- If you intend to download the document as Open Document Format (.odt) and open it in either Libre Office or Open Office, use Description. It survives the export/import, but the Title field does not.
If your original document is in Libre Office
- If you intend to export the document to either HTML or tagged PDF, use Title. It's used as alt text in both formats, and Description is lost.
- If you intend for the document to be opened in Google Docs, the Description survives, but Title does not.
- If you intend for the document to be opened in Word, know that Word is a little finicky about ODT files. In my current test I wasn't able to get Word 2011 for Mac to open any ODT file produced by Libre Office. However, Office 2013 for Windows opened all my files, and both Title and Description are intact.
If you just want to remember one thing: Use Description, not Title. This works more often than not. The only scenarios in which Title is a better alternative are:
- When importing from Word into Google Docs.
- When exporting from Libre Office to HTML or PDF.