Accessible Charts and Graphs: How to Make Your Data Understandable for Everyone

You spent hours building the perfect chart. The sales are trending up and to the right, the colors match your brand, and the slide looks fantastic in the boardroom. Then you publish it on your website or email it to customers — and for a meaningful slice of your audience, that beautiful chart communicates absolutely nothing.

This is one of the most overlooked accessibility problems on the web. Charts, graphs, and infographics are images, and like any image, they are invisible to people who use screen readers unless you give them a text alternative. Worse, even people who can see the chart may not be able to read it: roughly 1 in 12 men and 1 in 200 women have some form of color vision deficiency, and a chart that distinguishes “this year” from “last year” using only a red line and a green line is a coin flip for them.

The good news is that you do not need to be a developer or a data scientist to fix this. Most of the work happens in the tools you already use — Canva, PowerPoint, Google Sheets, Excel, your CMS — and it comes down to a few habits. Let’s walk through them.

Why charts are harder than regular images

With a normal photo, a short caption usually does the job: “A barista handing a coffee to a customer.” Charts are different because they carry data, and data has structure. A line chart isn’t just “a line going up” — it’s a set of values over time, with a trend, a peak, and a low point. An infographic might pack five statistics, a process diagram, and a call to action into one graphic.

If you describe a chart with three words of alt text, you have technically added an alternative, but you have thrown away the actual information. The goal is not to describe what the chart looks like — it’s to convey what the chart tells you. That distinction is the heart of accessible data visualization, and it changes how you write every alt text from here on.

This connects to a WCAG requirement called 1.1.1 Non-text Content, which says every image that conveys information needs a text alternative that serves the equivalent purpose. For a chart, “equivalent purpose” means the reader gets the same insight, even if they never see the picture.

The three layers of an accessible chart

Think of an accessible chart as having three layers, each serving a different reader.

Layer 1: A short alt text for the headline. This is what a screen reader announces. It should state what the chart is and its single most important takeaway — not every number. For example: “Bar chart of monthly revenue, January to June 2026. Revenue grew steadily from $12,000 to $31,000, with the sharpest jump in May.” Someone listening gets the point in one sentence.

Layer 2: The underlying data, in text. A screen reader user — or anyone who wants the specifics — needs access to the actual numbers, not just the summary. The best way to provide this is a simple data table near the chart, or the figures written into the surrounding paragraph. A chart should almost never be the only place a number appears on your page.

Layer 3: A visible caption or explanation that benefits everyone. A short sentence under the chart explaining what it shows helps sighted readers too — including people with cognitive disabilities, people skimming on a phone, and people who just don’t read charts quickly. Good captions are not redundant; they are a courtesy to your whole audience.

Get these three layers right and your chart works whether someone sees it in full color, sees it in grayscale, or never sees it at all.

Writing alt text for a chart

Here is the simplest way to think about it: imagine you are describing the chart to someone over the phone who needs to make a decision based on it. You wouldn’t read out every gridline. You would say what kind of chart it is, what it measures, and what it shows.

A reliable formula:

  1. Chart type and subject — “Line chart of website visitors per month…”
  2. Time frame or categories — “…from January to December 2026…”
  3. The key insight — “…showing a steady climb that doubled after the spring product launch.”

Keep it to one or two sentences. If the chart is genuinely complex — a multi-series graph, a dense infographic — don’t try to cram everything into alt text. Write a brief alt text that points to a fuller description: “Infographic summarizing our 2026 customer survey; full results in the table below.” Then put the real detail in accessible text on the page.

Avoid the two classic mistakes. The first is empty or filename alt text — chart-final-v2.png tells a screen reader user nothing. The second is the over-literal description — “A graph with bars of different heights and a blue line” — which describes the picture without conveying a single fact. Both fail the same test: would a person who can’t see the chart be able to act on it? If not, rewrite.

If you write alt text regularly, our complete guide to writing alt text goes deeper on the patterns, and accessible images beyond alt text covers the cases where alt text alone isn’t enough — which charts very often are.

Don’t rely on color alone

This is the single most common chart failure, and it has nothing to do with screen readers. Many charts encode their meaning purely in color: a pie chart where each slice is a different shade, a line chart where the only thing separating “Product A” from “Product B” is red versus green.

For someone with color vision deficiency, those distinctions can collapse into the same muddy tone. They see the chart perfectly well — they just can’t tell the categories apart, which makes the chart useless.

WCAG calls this out in criterion 1.4.1 Use of Color: color must never be the only way information is conveyed. The fixes are easy and they make your charts clearer for everyone:

  • Label data directly. Put the category name next to its line or beside its bar, instead of relying on a color key off to the side. Direct labels help every reader, not just colorblind ones.
  • Add a second visual cue. Use solid, dashed, and dotted line styles; different shapes for data points (circle, square, triangle); or distinct fill patterns (solid, striped, dotted) in bars and pie slices.
  • Choose colorblind-safe palettes. Avoid red/green as your only contrast. Blue and orange, for instance, stay distinguishable for the most common types of color blindness. Many tools now offer a “colorblind-safe” palette option — use it.

A quick test: convert your chart to grayscale (most image editors and even your phone’s accessibility settings can do this). If you can still tell every series apart in black and white, you’re in good shape. If everything blurs together, color is doing too much of the work.

Make sure the chart itself has enough contrast

Beyond category colors, the chart’s text and lines need to be readable. Thin, pale gridlines on a white background, light-gray axis labels, and faint data labels all fail people with low vision — a group far larger than people who are fully blind.

Aim for the same contrast targets you’d use for body text: a 4.5:1 ratio for normal-size text like axis and data labels, and at least 3:1 for the meaningful graphical elements like bars, lines, and their boundaries. If your chart tool lets you bump up the label size and darken the gridlines, do it. Crisp, high-contrast charts are easier for everyone to read, especially on a projector or a phone in sunlight. Our color contrast guide walks through how to check ratios with free tools.

Infographics: the toughest case

Infographics deserve special mention because they are the worst offenders. A single infographic might combine statistics, icons, a flowchart, and persuasive copy — all baked into one flat image with no text alternative at all. To a screen reader, that entire rich graphic is silence.

Because you can’t reasonably stuff an infographic into one alt text, the right approach is to reproduce its content as real, structured text on the page. Use real headings, short paragraphs, lists, and a data table for any figures. The infographic then becomes the visual version of content that already exists in accessible form, and your alt text can simply say what it is: “Infographic: 5 steps to an accessible website. Each step is described in the text below.”

This has a happy side effect: that text is also what search engines read. An infographic alone is invisible to Google; the accessible text version is indexable, which means accessibility and SEO pull in the same direction here.

A note on PDFs and reports

A huge number of charts live inside downloadable reports, annual summaries, and one-pagers. Exporting a chart-filled slide deck to PDF does not make those charts accessible — they’re still flat images inside the document, often with no tags and no alt text.

If you publish reports, the chart inside the PDF needs alt text and, ideally, a nearby data table, just like a chart on a web page. Our guide to accessible PDFs covers how to tag documents and add alternatives so a screen reader can navigate them. And whenever you have a choice, consider publishing the key data as a real web page with an accessible HTML table instead of — or alongside — the PDF. HTML is far easier to make accessible than a PDF, and easier for your readers to use on a phone.

A simple workflow you can adopt today

You don’t need to overhaul everything at once. Next time you publish a chart, run through this quick checklist:

  1. Write a one-sentence takeaway as alt text — chart type, subject, and the key insight.
  2. Put the numbers in text — a small data table or the figures in the surrounding paragraph, so the chart isn’t the only source.
  3. Kill color-only meaning — add labels, patterns, or shapes so the chart survives in grayscale.
  4. Check contrast — darken pale labels and gridlines so they meet readable ratios.
  5. For infographics, write out the content as real text and let the graphic be the visual layer.

That’s it. Five habits, applied to the tools you already use, and your charts go from excluding part of your audience to working for all of it. The customers, donors, investors, and readers who couldn’t access your data before will now get the same insight as everyone else — and your reports will be clearer, more searchable, and more professional for it.

Accessible data visualization isn’t about dumbing down your charts. It’s about making sure the story your data tells actually reaches every person you’re trying to reach.

We’re building a simple accessibility checker for non-developers — no DevTools, no jargon. Join our waitlist to get early access.