Alt text on a chart tells a screen reader what the chart shows

When you add alt text to a chart in Excel, you are writing a short description that a screen reader reads aloud to someone who cannot see the image. The alt text should explain what the chart displays — the data it represents, the trend it shows, or the conclusion it supports — not just say "chart" or "graph".

Excel stores alt text in the chart's properties. A screen reader pulls that text and reads it in place of the image. Someone using a screen reader will hear your description instead of being blocked by a visual-only chart.

This matters because charts are common in spreadsheets, and a chart with no alt text is invisible to assistive technology. Adding alt text takes less than a minute per chart and makes your file usable for more people.

Key Takeaways

  • Right-click the chart, select "Format Chart Area", and go to the "Alt Text" tab to add a description.
  • Write what the chart shows in plain language — for example, "Sales increased 15% from January to March" rather than just "sales chart".
  • Keep alt text under 125 words; if the chart is complex, put the full explanation in the spreadsheet text and use alt text as a summary.
  • Test your alt text by using Narrator (Windows) or VoiceOver (Mac) to hear what a screen reader will read aloud.

How to open the alt text box in Excel

Right-click directly on the chart itself — not on the spreadsheet behind it. A menu will appear with several options. Look for "Format Chart Area" near the bottom of the menu and click it.

A panel will open on the right side of your screen. At the top of that panel, you will see several tabs. Click the tab labeled "Alt Text". You will now see two fields: one for a title and one for a description.

If you are using Excel on the web, the steps are slightly different. Click the chart once to select it, then look for the "Alt Text" button in the toolbar at the top of the page. It may appear under a menu labeled "Review" or "Accessibility" depending on your version.

What to write in the title and description fields

The title field should be short — one to three words that name what the chart is about. Examples: "Q1 Sales", "Temperature Trend", "Budget Breakdown". This is optional; you can leave it blank if the description is clear enough on its own.

The description field is where you explain what the chart shows. Write as if you are describing it to someone who cannot see it. Include the type of chart (bar chart, line graph, pie chart), the main data points, and the key takeaway. For example:

Bar chart showing monthly sales for three product lines. Product A grew from $50,000 in January to $65,000 in March. Product B remained flat at $40,000. Product C declined from $35,000 to $28,000 over the same period.

If your chart is straightforward — just a few bars or a clear trend — one or two sentences is enough. If it is complex with many data points, aim for three to four sentences. Do not exceed 125 words; if you need more space, put a detailed table or explanation elsewhere in the spreadsheet and summarize it in alt text.

How to describe different types of charts

A bar or column chart should name the categories and the values that stand out. Example: "Column chart comparing website traffic by source. Organic search accounts for 45% of traffic, direct visits 30%, and social media 25%."

A line chart should describe the trend and any notable changes. Example: "Line graph showing stock price over six months. Price rose steadily from $50 in January to $72 in April, then dropped to $65 by June."

A pie chart should list the segments and their proportions. Example: "Pie chart of household budget. Housing is 35%, food 20%, utilities 15%, transportation 20%, and other expenses 10%."

A scatter plot should explain what each axis represents and what the pattern shows. Example: "Scatter plot of study hours versus test scores for 30 students. Shows a positive correlation: students who studied more generally scored higher."

Testing your alt text with a screen reader

After you write alt text, test it by listening to how a screen reader reads it aloud. On Windows, use the built-in Narrator tool. Press the Windows key and the letter H together, then search for "Narrator" and open it. On Mac, use VoiceOver: press Command, Option, and F5 together to turn it on.

Once the screen reader is running, click on your chart. The screen reader will read your alt text aloud. Listen to whether it makes sense and whether someone unfamiliar with the spreadsheet would understand what the chart shows. If the description is unclear or too vague, go back and revise it.

You do not need to leave the screen reader on permanently. Use it just to test each chart, then turn it off when you are done.

Common mistakes to avoid

Do not write "chart" or "image" as your alt text. A screen reader already knows it is a chart; your job is to say what the chart contains. "Chart showing sales data" is not useful. "Sales increased 20% quarter over quarter" is.

Do not try to describe every single data point if the chart has dozens of values. Pick the most important ones — the highest, lowest, or most relevant to your message. If someone needs the exact numbers, they can look at the underlying data table.

Do not use the alt text to repeat information that is already in the spreadsheet text above or below the chart. If your paragraph already says "Revenue grew from $100,000 to $150,000", your alt text should add context, not repeat it.

Where alt text appears and who sees it

Alt text is invisible to sighted users looking at the spreadsheet normally. It only appears when someone uses a screen reader, or when they right-click the chart and look at its properties. Some accessibility checkers will also flag charts without alt text.

If you share your Excel file with others, the alt text travels with it. Anyone who opens the file and uses a screen reader will hear your description. If you export the chart as an image and paste it into another document, the alt text does not transfer — you will need to add it again in the new location.

If you publish your spreadsheet online or convert it to PDF, check whether the platform preserves alt text. Some tools do; others strip it out. Test the final version to make sure your descriptions are still there.

Frequently Asked Questions

Do I need alt text for every chart in my spreadsheet?

If the spreadsheet is only for your own use, alt text is optional. If you share it with others, especially colleagues or the public, adding alt text makes it usable for people with vision loss or who use assistive technology. It is good practice to add it to any chart that conveys important information.

What if my chart is just decorative or illustrative?

If the chart is purely decorative and the data is explained in text elsewhere, you can leave alt text blank or write "Decorative chart" so a screen reader knows to skip it. But most charts in work or school spreadsheets carry meaning, so they should have a real description.

Can I copy and paste the same alt text for similar charts?

No. Even if two charts show the same type of data, the values and trends may differ. Write a unique description for each chart so the alt text is accurate. Copying generic alt text defeats the purpose of making the chart accessible.

What if I update the chart data — do I need to update the alt text too?

Yes. If the data changes significantly — for example, a trend reverses or new categories are added — update the alt text to match. Check your alt text whenever you make major changes to the chart.

Does alt text work the same way in Google Sheets?

Google Sheets has a similar feature. Right-click the chart, select "Chart options", then look for an "Alt text" field. The process is slightly different, but the principle is the same: write a clear description of what the chart shows.