ALT Length Test
This page was designed to test whether there is a maximum size for ALT attributes supported by common screen readers. See results at bottom.
95 characters (112 counting spaces)
![This is just your basic ALT text consisting of 95 characters without spaces and 112 characters including spaces.]()
245 characters (296 counting spaces)
![This is a considerably longer ALT attribute because it uses a lot of superfluous verbiage and rambles on and on about nothing if you know what I mean and when the final count is tallied it turns out this ALT attribute consists of 245 characters without spaces and 296 characters including spaces.]()
645 characters (787 counting spaces)
![My suspicion is that if a screen reader were to cut off ALT text at some point it would probably not be an arbitrary cut off, it would probably be one based on something logical even if the logic was not obvious to the user. For example, a cutoff 256 makes since because it follows the logic of binary arithmetic and such. The purpose of this paragraph, however, is not to actually determine or teach anything, but to fill an ALT attribute with an unreasonable amount of text just to see if there are any screen readers that would actually read the entirety of this text - I sure hope not. All of this padding really serves no purpose other than to bring the total character count for this ALT attribute to an astounding 645 characters without spaces and 787 characters including spaces.]()
Results:
- JAWS 6.0 - reads ALT text in 125 character chunks (excluding spaces).
If ALT text exceeds 125 characters, it divides it into multiple graphics,
each having no more than 125 characters of ALT text, beginning where
the previous graphic left off.
- WindowEyes - reads all ALT text.
- IBM HPR - reads all ALT text
- Lynx - Displays entire ALT text, regardless of length.
- IE - If height and width are provided, ALT text is truncated to fit within the image box. If not, entire ALT text is displayed, and doesn't wrap so long text requires scrolling right. Entire AlT text is displayed within tooltip bubble, which resizes to fit.
- Firefox - Same as IE, although if there are no size constraints firefoxes uses the window size as a constraint, and wraps ALT text.