This Best Practices document reviews key guidelines to writing image descriptions. Whether you are a publisher, freelancer, author, or anyone else, this document will help you make decisions about how and what to describe.
Writing image descriptions is both an art and a science, and it definitely takes some practice to get the hang of! To help you as you write, keep the following guidelines in mind:
Don’t Describe Decorative Images
Decorative images whose only purpose is to enhance visual appearance do not need a description since they do not convey any useful information to the reader.
Here are two questions to ask yourself when deciding whether to write a description or not:
Is the image purely aesthetic? This could be borders, backgrounds, or small decorative images. For example, drawings of banana peels and eggshells beside a list of compostable foods would not require alt-text.
Will the image come up in conversations such as in a book club or discussion with friends? This could be cover images, or even author photos. If it prompts discussion, it is not decorative, and therefore needs alt-text.
Describe Cover Images
Cover images are often overlooked when it comes to writing image descriptions, but they are important images and should always be described! The following format is recommended:
alt=”Cover: [Title] by [Author]. Image: [Brief description]. [Any other text on the cover].”
In most cases, the font of the text does not need to be described, unless the designer or author feels that it should. Whenever possible, we recommend getting input from the people who have made the image or font selection.
Logos are also often skipped, but they do require descriptions. They are not considered decorative, as they convey information!
Logo descriptions can be kept simple, like alt=”Logo: Government of Canada”, or can be more descriptive, like alt=”Logo: Canada is in large black letters, with a small, red Canadian flag over the letters.” As long as there is a description of the logo, the level of depth of the description is up to you.
Use a Clear Structure
One of the most basic tips for writing image descriptions is: Work from the general to the specific. In other words, provide an overview of the image before you describe specific details. A strategy you might use is to break the image up into its component parts, and then organize them so that the description makes logical sense.
For charts and graphs, we recommend providing an overview such as the type of visualization, the labels on the axes, and the number of lines, before getting into the details where you would describe the shape of particular lines or trends. Examples, and more information on describing charts can be found in “Writing Descriptions for Complex Content” (see Step 5 in Next Steps below).
This example provides a description that gets more and more specific. An interesting way to think about it is: does the first sentence provide a good overview of the image? It should do this, so the reader is oriented to the image, and has a context for understanding more details.
Alt text: An outdoor garden on a sunny day, overlooking a forested valley. The garden is made up of five raised beds, about 3 feet by 5 feet each. Nothing appears to be planted, but one of the garden beds is sprinkled with mulch. To the left of the beds, there is a wooden bench. At the bottom of the picture, a coiled hose is partially visible.
If the image is a photograph of a person, you will probably want to first give an overview of the scene, including things that immediately jump out at you such as special photography effects or anything that is prominently portrayed in the image. Next describe the setting, expressions, and if applicable, any action taking place. Finally, describe what the person is wearing. The order is general – if the image is of a clown, you may want to describe their outfit earlier – but if they are jumping through a flaming hoop, the action may take precedence. Use your judgment, and don’t be afraid to ask for help or a second opinion!
Alt text: A light-skinned young man stands in a stairwell in the day-time, with his hands in his pockets. He gazes off to the side and his mouth is closed. He has a close-cropped beard with a thin mustache and solid dark eyebrows. He wears a black New York Yankees cap, waist length black leather jacket, white t-shirt, and black pants.
Write Descriptions Based on Context
Context is important. The audience, surrounding text, related images, and many other factors will influence the description you are making. Consider language, style and tone. Try to write descriptions that match these elements based on the surrounding text. You can do this as long as it is introduced in your content prior to the reader coming across the picture or in the surrounding text where there is a clear connection to the image.
Alt-text: Curved, straight, thin, thick, solid, and broken lines, some of which have straight crisp edges while others are imperfectly straight with fuzzy edges.
In the surrounding text and caption within the body of the book, it is explained that the image is a drawing of lines. We have therefore not included the word “drawing” or “illustration” at the beginning of our alt-text. The text discusses the quality and interpretation of different lines in general, but does not discuss specific lines from the image. Thus, we do not have to describe all 8 lines individually, and a Long Description is unnecessary. Instead we just need to provide a little more information that can help the reader fully understand the passage, such as the visual effects of hand-drawn versus digitally drawn lines. The passage refers to the effect briefly but without the alt-text, the reader might not be able to easily glean this from reading the text.
For a more esoteric example, let’s take a look at a page from Rivka Galchen’s Atmospheric Disturbances:
In this example, in the book Atmospheric Disturbances by Rivka Galchen, the narrator describes the Doppler effect in relation to how he perceives his wife. It’s somewhat confusing conceptually, but actually quite well described in the text: “Let us imagine a source from which a Rema look-alike emerges every second. If the source is stationary, and I am stationary, then every second one of these Rema’s will pass me by. But if the single observer…begins walking toward the source of Remas, then a Rema will pass by me more frequently than every second, even though Remas are still exiting the source at the precise rate of one per second.”
Therefore, only simple alt-text is required, as the author has done the heavy lifting!
Write for Your Audience
Always consider the audience when writing image descriptions. Understanding the age of the intended reader or the type of person who will be interested in the content will help you craft a description that can be easily understood. For example, do not use complex terms that adults would understand but children might find challenging if your book is intended for young readers.
Alt-text: A smiling Humpty Dumpty jumps out of a pot which is sitting on a fire! The brown pot has a smiling face on its curved side, and yellow and orange flames move around the pot like they are dancing. Humpty Dumpty is stained with a red stripe around his middle, and red spots below – it almost looks like he is wearing polka-dot underwear.
Since the book is for children, simple language has been used (i.e. pot instead of kettle), and an effort has been made to match the tone of the story.
Aim for Conciseness
Depending on how busy the picture is, you should try to describe it with no more than two to three sentences (as a general rule of thumb). As long as it clearly describes the image, it will serve its purpose.
If the image is highly complex and technical, you can write a Long Description that will go on a separate page or in the surrounding text. Remember to still provide alt-text for an image even when you offer a Long Description
Do not include phrases such as “Image of” or “picture of” as part of your description. Screen readers will announce if an image is detected, but do not have the ability to describe what is contained in the image; hence the need for alt-text. An exception to this is when you are providing more descriptive vocabulary, so if the picture is of a map or illustration, it is helpful to write “Illustration of” or “Map of” at the beginning of your description. Additionally, it may occasionally be contextually important to include these phrases – use your judgement.
Use Present Tense / Action Verbs
In order to be engaging, use action verbs to describe what is happening in the image. This is the most natural-sounding voice for image descriptions.
Here is an example from Ian Grandin’s Age of Discovery:
Alt-text: A line drawing of a man with no skin, demonstrating the musculature of the human body. With one raised arm, he takes a step. He is in a field dotted with foliage and ruins of ancient buildings.
In this example, the first sentence describes the main purpose of the image, and the following sentences use present tense and active voice to provide an engaging description.
Objectivity is key when it comes to image descriptions!
Objectivity and People
Describe what you can see such as physical appearances and actions rather than intentions based on your interpretations. We as humans tend to shy away from discussing ethnicity, race, gender, disability, and age for fear that we would misjudge and use the wrong language but remember that whether you want to or not, you can immediately see these characteristics when you look at a photo. This is information that people with print disabilities should receive, so that all readers have access to the same information and can therefore make their own interpretations.
In order to be objective, we suggest using the following terminology to describe skin tone:
Light Skin Tone
Medium-Light Skin Tone
Medium Skin Tone
Medium-Dark Skin Tone
Dark Skin Tone
This is the same system that is used to label emojis with different skin tones. You can also use terms such as Black, white, South-east Asian, Middle Eastern, etc. but only if this information is also given in the surrounding text.
You can identify the subject as male or female, man or woman, if it can be clearly identified. Try to describe the physical characteristics and avoid using the terms “masculine” or “feminine” since it is more interpretive than descriptive. There is a delicate balance to strike between inclusive language and robust description; do your best, and ask for opinions from others if you need to.
Avoid describing age by prescribing a number or the decade because someone could appear young but is in their fifties. Instead, Use terms such as baby, toddler, teen, adult, middle aged, young, old, etc.
Expressions can be tricky. Words and phrases such as “grinning”, “intense look”, or “serious expression”, might be somewhat interpretive, depending on the context. If possible, describe how the physical characteristics appear. For example, instead of saying “neutral look” we can say “mouth closed and lips touching”; instead of saying “surprised look”, say “raised eyebrows and a wide open mouth”.
Let’s take a look at this stock image:
Alt-text: A group of 5 people – men and women – stand in a circle with their arms around each other; they are smiling and looking down at the camera which looks up at them from the centre of their circle.
For most purposes, this alt-text would be enough. But, if a longer description was needed, based on the context, something like this would work:
Long Description: Five people – three women and two men – stand in a circle. They are all smiling widely and have their arms around each others’ shoulders. The upper portion of their bodies and their faces are visible as they lean forward and look down at the camera, which is in the middle of their circle; it appears as though they are looking at the reader.
Counterclockwise from the left: a dark-skinned young woman with black, natural, chin-length hair. She wears a white blazer over a dark green t-shirt. Next to her is a light skinned middle aged man with short blonde hair. He wears a blue sports jacket and a gray collared shirt with a necktie, decorated with narrow diagonal lines. Beside him is a medium-light skinned, middle-aged man with salt and pepper hair and beard. He has a closely trimmed beard and mustache. The man wears a dark gray blazer over a white checkered shirt and a maroon tie. Next to him is a dark-skinned, middle-aged woman with a round face and natural, mid-length hair. She wears a patterned white wool high neck sweater. The fifth person is a light skinned, middle aged woman with chin-length blond hair. She wears a cream color jacket over a powder blue blouse.
Objectivity and Things
Assumptions can be wrong, and contribute to an incorrect understanding of a work.
So avoid objectifying words like “pretty” or “ugly”, even when discussing objects. Like, if there is a dirty, ragged, tattered couch, use those words to describe it instead of deferring to a simple word that might not be universally accepted.
The goal of objectivity is to allow readers to make their own judgements.
Alt-text: A newspaper ad for a 1984 Mercury Marquis Wagon. One picture is of a brown, wood-paneled station wagon in a field. The other is a blue station wagon, on a road by a beach.
This objective description simply describes what the image show – no more, no less!
Do Not Censor
A concern that people with print disabilities have is the censorship or watering down of content from the describer due to the image containing disturbing or controversial material. People with print disabilities require equal access to the same content, and must be allowed to make the same choices for consumption of images.
This image is from the British Museum:
Alt-text: Four nude satyrs engage in drinking and revelry. One leans back on his hands, balancing a cantharos on his erect phallus. One pours wine into the cantharos; another stands behind him, holding a cantharos overhead. To the right, the fourth satyr dances around another cantharos, set on the ground.
This is a mild example, but nevertheless demonstrates the importance of not censoring – readers need to know what is in the image, even if if may be sexual, violent, or other uncomfortable topics to describe.
You don’t want to be like the early British Museum, and erase an important part of history, like they did in their earlier images:
Alt-text: Black and white version of above image of satyrs on a vase, with one key difference: the phallus is covered over in black, so it looks like the cantharos is floating above the satyr’s lap.
Write Out Text in Images
There are many images where the text is embedded within the picture. In order to make these accessible, the text will probably need to be written out as part of your description. While some people may use optical character recognition (OCR) software, which can extract text from images and even place it in the alt-text field (something that Facebook does!), it is unreliable. If you do use this technology, we recommend using OCR as only a part of your workflow to make the image accessible, because OCR translations can have errors.
In some cases of text in images, you’ll need to review the context and use your best judgment to decide what to include. Some examples:
If it is an image of a protester holding a sign, the reader would probably want to know the text on the sign.
If it is a scan of a page of a newspaper, the context will be key: is the text easily legible, and intended to be read in full by the reader? Or, is the image included to showcase a headline, date, or the name of the newspaper?
Deciding what to include, and what to exclude, when it comes to text in images can be a challenge! Use your best judgment, and don’t be afraid to ask for a second opinion.
Alt-text: The text on the sign reads “Votes for Women”. The three women wear long dresses and wide brimmed hats with elaborate decorations on top. The women to the left and right wear sashes with illegible text (only some letters are readable: SUF; WO); the woman in the centre stands behind the large sign.
Alt-text: Cover page of the June 28, 1919 edition of The Evening World. The top headline (in large block letters) reads “Treaty Signed; War Over”. Other headlines from the cover page read: “Wilson Leaves Paris; Sails Sunday”; “Germans Pledged to Act In Good Faith”; “City’s Bells Ring Tidings as Peace Treaty is Signed; Fleet Joins in Celebration”; “Treaty Severe on Germany, says Wilson, but Imposes Nothing She Cannot Do”; “Guns Boom, Planes Fill Air; French Crowds Cheer Peace”.
In the alt-text we created for this newspaper page, we made a judgement about how closely a reader would read it. Some may read more than what was included in the alt-text, but providing the main headlines is sufficient.
Don’t Rely on Captions
A common mistake is including captions, but no alt-text. Captions are often insufficient, and assume that readers are accessing the text visually. For example, a caption might state the names of people in a photo and just leave it at that, and not describe any key characteristics or the setting. The problem with this approach is that the reader relying on alt-text will miss key elements.
You don’t need to repeat information that is provided in the caption – just make sure that the caption and alt-text complement each other to provide a complete description.
This example is from Margaret Trudeau’s Changing My Mind:
Alt-text: Margaret sits in a wooden rocking chair, holding a baby Justin in her arms as she smiles down at him. They are both wearing light, white clothing.
In this example, we have a caption that does not describe the image well, for readers who need alt-text. Therefore, more description is needed in the alt-text to explain that Justin Trudeau is an infant in the image.
Do’s and Don’ts
These do’s and don’ts reiterate some key points from the best practices above.
Do work from general to specific.
Do be clear and concise.
Do be objective. The reader should have the freedom for their own interpretation given all the necessary details.
Do state the type of image if it is unusual or out of context, like a children’s drawing among a set of family photos in a memoir. (In this case, you would say “A drawing of…”)
Do pay attention to the context of the image. Is it well-described within the text? Then the alt-text can be simple.
Do review and edit your alt-text. Ask for help, or use TTSReader.com to hear a screen reader read your text.
Don’t start each description by saying “An image/picture of…”. The screen reader will have already indicated that this is an image.
Don’t censor: If you are uncomfortable describing a scene, whether it is violent, sexual, or something else you feel you cannot objectively describe, you must ask someone else to describe the content.
Don’t include any paragraph breaks or styling in your alt-text. Alt-text can only be a string of text and punctuation.
Don’t leave the filename in the alt-text
Don’t rely on Word’s automatically generated image descriptions
Reviewing Image Descriptions
Guide for Reviewing Image Descriptions
This guide shares a short checklist of items to review when reading or editing image descriptions. Whether you wrote them yourself, or someone else wrote them, this guide will help ensure the quality of descriptions.
Subject(s): Digital Marketing, Ebook Production, Image Descriptions, Website Accessibility
Resource Type(s): Checklist, Standards and Best Practices
Writing Descriptions for Digital Media
Introduction to Writing Alt-text for Digital Media (other than ebooks)
Images used on websites, social media, and other non-book content need image descriptions. The writing guidelines are mostly the same, but there are a few additional things to consider. This Introduction document looks at these,…
Subject(s): Digital Marketing, Image Descriptions
Resource Type(s): Checklist
Writing Descriptions for Complex Content
Introduction to Writing Descriptions for Complex Content
This resource introduces the concept of long/extended descriptions, and provides a general discussion of how to approach and develop them.
Subject(s): Image Descriptions
Resource Type(s): Standards and Best Practices
External Links to More Information
Guide to Image Descriptions
A thorough introduction to image descriptions; it discusses: the importance of image descriptions, workflow considerations, and terminology; it also provides some technical guidance and code samples, and of course provides detailed image description guidelines, with examples!
Poet Image Description Tool
Developed by The DIAGRAM Center, the Poet image description tool is an open-source, web-based tool for creating and providing guidelines to writing image descriptions for images in existing books. Some people may find it a useful tool!
This page from the Diagram Center has several resources about image descriptions: the Poet image description training tool, diagram image description guidelines, a sample book, some archived presentations, description templates for common graphics, and some survey results documenting the value of image descriptions.
Describing Images in Publications
An archived webinar from the DAISY Consortium on June 17, 2020 which gives an overview of image description. It has information about the Poet image description tool from the DIAGRAM center, tips and examples for writing descriptions, some comments on automatically generated descriptions (can identify the category but descriptions are not yet adequate) and some publisher processes for adding them. DAISY webinar archives include the video of the webinar, a written summary, presentation slides, a transcript, and links to further resources.
The Art and Science of Describing Images
An archived webinar from the DAISY Consortium on July 22, 2020 on the topic of image description. It discusses several types of diagram-style images and how to describe them. Most are different types of charts. DAISY webinar archives include the video of the webinar, a written summary, presentation slides, a transcript, and links to further resources.
The Art and Science of Describing Images-Part 2
An archive of a webinar in the series on describing images from the DAISY Consortium given on December 2, 2020. It covers maps, timelines and bar charts. DAISY webinar archives include the video of the webinar, a written summary, presentation slides, a transcript, and links to further resources.
The Art and Science of Describing images-Part 3
An archive of a webinar in the series on describing images from the DAISY Consortium on February 10, 2021. This covers artwork, anatomy and assessment images.
Implementing Extended Descriptions in Digital Publications, Best Practices and Practical Advice
An archived webinar from the DAISY Consortium on February 24, 2020 focusing on image log descriptions. It discusses three approaches for including them: in the text following the image, using a collapsible details element, and linking to a description at the end of the book.
Image Description: Advice From the Front Lines
This post gives approaches by four publishers on how they produce image descriptions. Some do it in house, and others use a vendor or the author. More complex images can benefit from someone with training in image description and knowledge of the subject.
How to Write an Image Description
This article gives ideas for writing image descriptions. It uses an “object-action-context” order to provide details in a logical way. It also includes some more suggestions for when to describe race and gender, and breaking more complex image descriptions into sections.