Alt Text for a Photograph of Your Work

Ask what the photograph is for

The same image needs different descriptions depending on why it is on the page.

In a gallery it is one of twenty examples of your work.

Beside a paragraph about a difficult access problem, it is evidence for that specific claim.

As a before and after pair, it is a comparison and the pairing is the content.

So the useful question is not what does this show, but what exactly would somebody miss if it were not there at all.

Describe the job, not the picture

• What the work was.
• What was difficult about it.
• The state, before or after.
• Anything the text refers to.
• Not the composition or the weather.

A roof is not a description. A replaced cedar shingle roof on a steep two-storey house, with scaffolding along the front, tells somebody what the photograph is evidence of.

Before and after need the pairing stated

Which is the case trades get wrong most.

Two images with descriptions saying driveway and driveway leaves somebody unable to tell what changed, which was the entire point.

Say which is which and what is different: cracked asphalt driveway with weeds through the joints, and the same driveway resurfaced with a new edge.

The second description referring back to the first is what makes the pair readable.

That is one extra clause and it converts two useless descriptions into a comparison.

Where the pair is the whole content, consider describing it once in the surrounding text as well.

A worked example

A business had thirty gallery photographs described as job, completed work, or the customer's surname.

They rewrote them over about an hour, at roughly two minutes each.

Each became a sentence naming the work, the type of property, and anything unusual about it.

Two unexpected things followed: the gallery started appearing in image search for specific phrases, and the descriptions became the starting point for the individual job pages they had been meaning to write.

The accessibility improvement was the reason for doing it and not the only return.

Descriptions written properly are useful to search, to future you, and to somebody who cannot see the image.

The caption does a different job

Which is worth separating.

A caption is visible to everybody and read by screen readers as well, so a photograph with a good caption may need very little description.

Where the caption already says what the image shows, the description can be short or the image marked decorative, since repeating it means hearing the same thing twice.

That is a judgement rather than a rule, and it is why blanket descriptions of everything read badly.

For a trade, captions are frequently the better choice anyway, since the information then helps every visitor rather than only some of them.

Write the caption first and then let it decide what the description still needs.

Length, honestly

Since this is where people get stuck.

One sentence is right for almost everything, and about a hundred and twenty-five characters is a reasonable ceiling.

Anything longer belongs in the surrounding text where everybody benefits from it.

Do not start with a photograph of, since screen readers already announce that it is an image.

And do not end with a full stop out of habit; it makes no difference either way and nobody should be worrying about it.

Do not put the customer in it

Which is a privacy point rather than an accessibility one.

Descriptions are read by machines and stored, so avoid the address, the surname, and anything identifying the property.

A house on Elm Street is worse than a two-storey house in the same neighbourhood.

The same caution that applies to what you post applies to what you write about it.

Where the photograph includes people, describe them only if their presence is the point and you have permission.

Reuse what you already wrote

Since the material exists.

The two sentences you wrote for the weekly post about that job are most of the description already.

So the habit of writing about what was difficult produces the raw material for this without any additional work.

Keep them together, with the photographs, in the same folder.

Writing the description while the job is still in your head takes thirty seconds and writing it a year later takes five minutes of guessing.

A business doing both has half the pages it needs already drafted, which is the recurring pattern in all of this.

The work done properly once tends to serve three purposes rather than one.

The surrounding text can do the work

Which is the option people forget exists.

Where a paragraph beside the photograph already explains that the rafters had rotted at the eaves and the whole section was replaced, the image description does not need to repeat it.

In that case a short description naming the subject is sufficient, because the detail is already on the page for everybody.

That is a better outcome than a long description, since information hidden in an image attribute reaches only some readers and information in a paragraph reaches all of them.

So the instinct to put the detail in the description is frequently a sign the detail belongs in the text instead.

The counter-case

A gallery of near-identical images is a limit.

Twenty photographs of similar work do not benefit from twenty near-identical sentences, and a short one each is genuinely enough.

Very long descriptions also make a page tedious to listen to, so restraint matters as much as effort.

And a photograph included purely for atmosphere is decorative even on a trade site, and should be marked as such.

Say what the work was and what was difficult, state the pairing on before and after images, and keep it to a sentence.

Writing one

1. Ask what it proves.
2. Name the work and the property type.
3. Add what was unusual.
4. State before or after explicitly.
5. Keep the whole thing to one sentence.
6. Leave out the address and surname.
7. Reuse what you wrote for the post.

Step four is the one trades miss, since a pair of images described identically tells nobody what changed and the change was the whole reason for showing both.

The general rules are covered in describing an image for somebody who cannot see it.

Frequently asked questions

West Coast Media Solutions Inc. provides web design, web development, hosting, digital marketing, and business consulting to organisations across Canada, drawing on more than twenty-five years in the field.