Saving failed: Feature image alt text cannot be longer than 125 characters.

[mhansen]

Issue Summary

Ghost(Pro) on Chrome.

To Reproduce

1. Add a feature image
2. Add alt text, e.g. for me "Profilers measure the OS/Hardware/Runtime, outputting Profile Data Formats. Converters can convert one Profile Data Format to another. Analysis UIs read Profile Data Formats."

Expected: be able to spell out the content of the image for vision-impaired users.

Actual: arbitrary limitation of 125characters for alt text; this is not enough to convey the depth of the diagram I'm trying to post. Vision-impaired users will be unable to understand this.

Fix: remove this validation check. I don't think there's a good reason to have it, and it disadvantages blind readers. I don't think this is what you intended. For some prior art, Twitter allows 1000 characters, but even that should probably not be limited.

Technical details:

• Ghost Version: Whatever's on Ghost(pro) right now
• Browser/OS: Chrome on macOS

[lmpham1]

I found the file where the max length for the alt text is defined:

Ghost/core/server/data/schema/schema.js

Line 76 in b48c16c

feature_image_alt: {type: 'string', maxlength: 191, nullable: true, validations: {isLength: {max: 125}}},

If a maintainer confirms that this is an issue that needs fixing, I can start working on it

[ErisDS]

Reference material for the 125 character limit: https://moz.com/learn/seo/alt-text
Full discussion can be seen here: #13030 (review)

We've followed accessibility guidelines and best practice here to the best of our ability.

I'm going to close as this is not a bug. We carefully consider data limitations before implementing them, not least because with our decentralised setup we have a strict policy on not running column alteration migrations outside a major version.

[mhansen]

While many sites reference a 100/125 character limit, I think they're based on ancient folklore that no longer applies in 2021. None of them really cite their sources, except a few that reference JAWS 6.0.

e.g. JAWS 6.0, a 16-year-old version of the screen reader, is documented as having this 125-character limit: https://terrillthompson.com/tests/altlength.html.

Current versions of screen readers have no limits on the size of the alt text they'll read: https://www.washington.edu/doit/how-long-can-alt-attribute-be

It seems that a more modern JAWS version reads 150 characters (by default), then asks the user if they'd like to continue the reading, or scroll past. 2 years ago, there are reports of JAWS stopping around 1000 characters: https://community.articulate.com/discussions/articulate-storyline/partial-reading-of-alt-txt-by-jaws

I think a few of the older references wanted you to use longdesc for long alt descriptions, but that got deprecated in HTML5: https://developer.mozilla.org/en-US/docs/Web/API/HTMLImageElement/longDesc, so I think longer alt attributes are the way to go now.

[stuartpb]

For comparison, the maximum length for alt text on Twitter is 1000 characters: https://help.twitter.com/en/using-twitter/picture-descriptions

[mhansen]

If you're going to close this as not-a-bug, could I make a feature request to enforce the text limit size in the client's textfield so we don't have to backspace some number of characters and retry saving, getting an error message each time, looping until it works?

(to be clear, my preferred solution would be: support longer alt-text; I just hit this issue again today trying to explain a graphic in alt text and failed, so unsighted readers just won't get the full context! it's a shame that tool limitations are getting in the way of accessibility. if this can't be fixed until a major version upgrade, could we get this on a list for the next major version?)