Images, emojis and hashtags on social media: a guide to accessible best practices

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You publish regularly on social media. You take care of your visuals, you choose your words, you select your emojis. And yet, part of your audience does not receive the same message as everyone else.

This is not a question of intention. It is a question of method. Blind, visually impaired, deaf or dyslexic people access your posts in a radically different way from yours. An emoji that a screen reader speaks aloud as “police car light, police car light”; a hashtag that text-to-speech spells out letter by letter without recognising the words; an image described by AI as “perhaps an image of smiling people” with no context: these are situations your readers encounter every day.

This second article in our series on social media accessibility gives you the practical tools to address these issues. Images, emojis, hashtags, formatting: here is what you need to know and what you need to do.

Images: how to write effective alternative text

Why images are particularly critical on social media

On a website, some images are purely decorative and do not need to be described. On social media, that is rarely the case. A photo, a poster, a campaign visual: almost every image you publish carries information that your text does not fully repeat.

Without alternative text, a blind person using a screen reader simply hears “image” or, worse, an automatic description generated by the platform’s artificial intelligence. These automatic descriptions, offered by Facebook, Instagram and Threads, regularly contain errors. They do not replace an alternative written by a human who understands the context of the post.

People with visual impairments are also affected: if an image contains text, that text is frozen in the image and cannot be enlarged, spaced or adjusted for contrast according to the person’s needs. The best approach is always to include the important information in the body of the message itself.

How to add alternative text, platform by platform

The feature exists on all major platforms. It is simply not very visible.

On LinkedIn, when drafting a post from a computer, insert the image and then click the “alt” or “Alt text” button that appears. A limit of 1,000 characters applies.

On Instagram, during the process of creating a post from a computer, expand the “Accessibility” section and fill in the “Write alt text” field. From the mobile app, this field is accessible in the advanced settings before publishing. For Reels, alternative text can also be configured in the advanced settings.

On Facebook, after inserting the photo, click “Edit” to access the photo details, then select “Alt text” and choose “Custom alt text”.

On X (formerly Twitter), add the image to your post and then select “Add description”. X even lets you enable an automatic reminder when you forget to fill in this field, in the accessibility settings.

On Mastodon, after inserting the media, click “Missing description” and write your text in the provided field.

If you use scheduling tools such as Hootsuite or Buffer, check that they pass your alternative text through to the platforms. This is not always the case, and checking after publication is recommended.

How to write good alternative text

Alternative text must convey the same information to a person who cannot see the image as to a person who can.

A few fundamental rules:

Do not write “Image of…” or “Photo of…”: screen readers already announce that it is an image. Start directly with the description.

Describe the useful information first. If your visual announces an event, start with the date, the location and the purpose of the event, not with “colourful poster with an illustration of…”.

Be precise and contextual. “A smiling woman” is not enough. “Marie Dupont, Director of ASBL Inclusion Luxembourg, at the digital accessibility conference on 12 June 2026” is useful.

Do not use alternative text to place SEO keywords. That is not its purpose, and it harms the experience of the people who depend on it.

If your image contains important text (a title, a date, key figures), reproduce that text in full in the alternative.

Good example: “Poster for the Digital Accessibility Awareness Day organised by Key4.lu on 21 May 2026 in Luxembourg City. Programme: conference from 9am to 12pm, practical workshops from 1pm to 5pm. Free registration.”

Bad example: “Photo from our event!”

Emojis: understanding how screen readers handle them

What you publish and what a blind person hears

Every emoji has an official description defined by the Unicode Consortium. A screen reader will speak that description instead of the visual emoji. What you see as a small sun, VoiceOver reads as “sun”. What you see as a smiling face with glasses, it reads as “face with sunglasses”.

The problem is not the emoji itself. The problem is inappropriate use.

The most common mistakes

Multiplying emojis. Publishing five emojis in a row produces five spoken descriptions one after another. An appeal for help preceded and followed by four “siren” emojis will be read aloud as “police car light, police car light, police car light, police car light, We need you, police car light, police car light, police car light, police car light”. The message is lost in the noise.

Emojis in the middle of a sentence. When an emoji is inserted into a sentence, its description is read just like the surrounding words. “The weather is nice 🌞 this morning” gives “The weather is nice sun this morning”, which is acceptable. “We meet at 🕐 2pm” gives “We meet at clock showing six-thirty 2pm”, which is confusing.

Emojis replacing words. Two “4” emojis are never read as “44”. They are read as “two keyboard key 4”. Never replace a number or a word with an emoji.

Confusion over descriptions. The “lightning” emoji is described as “high voltage sign”. The “moon” emoji can refer to several variants, each with a different description. Before using an emoji, check its description on a reference site such as Emojipedia.

Rules to follow

One emoji is enough to draw attention. Place it at the end of a sentence or at the end of a message, never at the beginning or in the middle. Avoid long strings of decorative emojis. And if you are unsure about an emoji’s description, choose a different one or leave it out entirely.

Hashtags: the capital letter that makes all the difference

The technical problem with compound hashtags

A single-word hashtag poses no problem. #Luxembourg is read perfectly well.

The problem comes from hashtags that combine several words. #digitalaccessibility is a sequence of 20 indistinct characters to a screen reader. Text-to-speech software cannot tell where one word ends and the next begins. It will either read the whole thing as one block, or spell it out letter by letter, depending on the software.

For people with visual impairments or dyslexia, this type of hashtag is also difficult to decipher visually. The absence of word separation slows down reading and can distort the meaning.

The solution: camelCase

CamelCase (or PascalCase) means capitalising the first letter of each word in the hashtag. #DigitalAccessibility instead of #digitalaccessibility.

This notation is enough for screen readers to correctly identify each word and read it with appropriate pauses. It also improves visual readability for all readers.

A few practical points:

Use accents where relevant: #AccessibiliteNumerique. Note, however, that on some platforms, an accented hashtag and a non-accented hashtag are treated as two distinct keywords.

Place hashtags at the end of your post, not in the middle of the text. Screen readers announce “link” before each hashtag. If your hashtags are scattered through the text, your message will be punctuated with “link hashtag X, link hashtag Y”.

Limit the number of hashtags. The more there are, the more laborious the reading experience becomes.

Fake bold, fake italics and fake columns: a practice to abandon

What these formats are

Online text generators allow you to transform your posts by giving them a “bold”, “italic” or “stylised” appearance. These tools are popular on LinkedIn and Instagram.

What they produce is not genuine typographic formatting. These are Unicode characters: mathematical symbols that visually resemble letters but are not letters.

Why this is a serious problem

Screen readers handle these characters in two ways: either they read them aloud as mathematical symbols, or they ignore them entirely.

In both cases, the information is lost. Real-world tests conducted with VoiceOver (Apple’s screen reader) show that entire passages of text in “fake bold” are simply skipped. The blind person receives a truncated message, without even knowing that information is missing.

Fake columns created with spaces produce the same effect. A screen reader reads in a linear order. What looks visually like a two-column layout is read line by line, in an order that makes no sense.

What to do instead

Social media platforms do not offer accessible typographic formatting in ordinary posts. This is a platform limitation, not yours.

On LinkedIn, the “article” format allows you to apply genuine formatting, including headings, bold text and lists, all compatible with accessibility. You can publish a short post and link it to a structured article that contains your detailed information.

For regular posts, use editorial techniques to organise information: blank lines to separate ideas, carefully chosen emojis to signal a list, and clear language that does not need visual emphasis to be understood.

The key takeaway: if you have used a stylised text generator to write your post, remove that formatting before publishing. It makes your message inaccessible to people who use a screen reader.

What this changes in your day-to-day practice

Applying these best practices does not significantly slow down your work. What takes time is the initial learning process: understanding why these rules exist, testing them with real tools, building new habits.

Writing alternative text for an image takes less than a minute once you know what to write. Checking a hashtag in camelCase takes a second. Removing duplicate emojis takes a few seconds.

What requires more time is reviewing an editorial charter, training a team, and defining shared standards. This work is not optional if you want your communication to be genuinely inclusive and compliant with the legal obligations applicable in Luxembourg.

Trainings available on request:

FAQ: accessible images, emojis and hashtags

Is it mandatory to add alternative text to all my images on social media?

For organisations subject to Luxembourg’s legal obligations (public sector bodies, non-profits largely funded by public money, companies subject to the 2023 law), yes. For all other organisations, it is a strongly recommended best practice and an ethical commitment to your audience.

Are automatically generated alt texts not enough?

No. These automatic descriptions, produced by the image recognition technology of Facebook, Instagram or Threads, regularly contain errors or inaccuracies. They do not know the context of your post. A description such as “perhaps an image of smiling people” does not allow a blind person to understand what your post is about.

How many emojis can be used in a post?

There is no fixed limit, but the common-sense rule is: one emoji per idea you want to illustrate, and never more than two or three in a single post. Always place them at the end of a sentence or message, not in the middle of the text.

Does camelCase affect how my hashtags are indexed?

CamelCase and lowercase hashtags are generally treated as identical by platforms. #DigitalAccessibility and #digitalaccessibility lead to the same aggregated posts. The use of capitals does not affect your reach. It only improves readability and how screen readers pronounce the hashtag.

How can I check an emoji’s official description?

The Emojipedia website lists all emojis with their official name and platform-specific variants. It is the reference to consult before using an emoji whose spoken description you are unsure of. Note that the site is in English and descriptions are given in English, but the official names are generally translated in French-language screen readers.

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