Alt text and accessibility
When publishing content on Facebook, Twitter and LinkedIn, the images we publish need alt text (alternative text, or alternative descriptions) to summarise the information presented for users who can’t see the graphic. It can also be used to describe what should be on the page if the web browser fails to load the images. Screen readers read the alt text out for people with visual disabilities.
Charts
Alt text for charts (chartbuilder or data vis charts) should include:
- the chart type used
- a summary of the main trend of the chart
The average UK house price was £256,000 in July, up £19,000 on a year ago but down £9,000 on last month https://t.co/ojiT1R6bqq pic.twitter.com/iLoaGSjKii
— Office for National Statistics (ONS) (@ONS) September 15, 2021
Alt text for this chart would be “Line chart showing average UK house prices fell to £256,000 in July 2021.”
Digitally designed graphics
Alt text for graphics created by our digital design team should include:
- a description of the imagery used
- the copy used in the graphic
Our latest analysis of personal well-being shows average ratings deteriorated in all indicators in the year ending March 2021:
▪️ life satisfaction: down 0.27
▪️ feeling things are worthwhile: down 0.15
▪️ happiness: down 0.17
▪️ anxiety: up 0.26➡️ https://t.co/RAXMwkhqyv pic.twitter.com/VUY1OCWNuU
— Office for National Statistics (ONS) (@ONS) October 15, 2021
Alt text for this graphic would be “Graphic showing map of the UK with a magnifying glass on a person’s figure. Text reads: Personal well-being in the UK: April 2020 to March 2021. Read our latest release.”
Graphics for statistician’s comments
Alt text for statistician’s comment graphics should include the text used in the graphic and the number, if more than one graphic is included.
Commenting on today’s retail sales figures, Deputy National Statistician for Economic Statistics @jathers_ONS said: (1/4) pic.twitter.com/6FmHVJbW6c
— Office for National Statistics (ONS) (@ONS) March 26, 2021
Alt text for this graphic would be “Quote from Jonathan Athow, Deputy National Statistician for Economic Statistics, ONS: “Despite national restrictions, retail sales partially recovered from the hit they took in January. Food and department store benefitted from essential retail remaining open with budget-end department stores seeing increased sales.” (1 of 4)”