Back in late 2023 I reviewed the number of councils using accessibility overlays (also known as accessibility or assistive toolbars). At that time I was aware that concerns have been raised about this technology, so I decided to find out which councils are using them and try to explore a little about why they choose to use them.
Two years on I have carried out another review to find out if there has been any change in the use of accessibility overlays by councils.
What are accessibility toolbars and overlays?
An overlay relates to a toolbar or plugin which is added to a website to try to improve its accessibility. Website add-on products claiming to improve accessibility go back to the late 1990s.1
Overlays generally appear as a clickable button on a website that brings up a range of controls. These controls let you change the visual appearance of the webpage or enable the website to be read out or translated into other languages. Controls may also include:
- adjusting the font size or type
- changing the contrast between text and background colours
- screen masks
- generating an MP3 of text
How many councils use accessibility overlays?
My research reveals that 113 councils (27.5% of all councils in the UK and Ireland) are currently using an accessibility overlay. This figure represents an increase of 10 councils using overlays (2.5%) since I last carried out this review in 2023.
| Accessibility toolbar provider | Number of councils 2025 | Number of councils 2023 |
| Total of councils using overlays | 113 (+10) | 103 |
| Total of councils not using overlays | 297 (-10) | 307 |
What concerns have been raised about overlays?
A growing number of articles have been written voicing concerns about using overlays. I have summarised the main concerns and referenced the sources in the footnotes below.
In brief it is claimed that overlays:
- can fix minor problems but not serious user experience issues
- conflict with and override a user’s existing assistive technologies like screen readers
- do not compare to manual accessibility audits
- do not work well on mobile
- do not offer an equal website experience for disabled users 2
- will not get you to 100% compliance … or even close3
- require activation to work4
- will hinder your website performance5
Do overlays enhance the overall accessibility of a council website?
I have thought about this question at length and cannot find much evidence to suggest that an overlay enhances the overall accessibility of a council website. Overlays provide a range of features which can help people with specific needs, such as to increase the size of text, change the colour contrast or have text read out to them. Overlays can fix minor problems, but not resolve serious user experience issues. Implementing an overlay does not magically make a council website fully compliant with accessibility guidelines.
If your council website has accessibility issues then they need to be identified, reviewed and fixed. From my experience in local government I think that fixing accessibility issues is a generally a lengthy ongoing task, rather than something that can be quickly or easily resolved. You have to play the long game and put the time and effort in to make sure that your website is fully compliant with Web Content Accessibility Guidelines.
Why do councils choose to use an accessibility overlay?
Whilst researching this topic back in 2023 I reached out to councils using overlays via LocalGovDigital Slack and LocalGov Drupal Slack respectively to encourage council colleagues to share their thoughts.
Reasons shared for using an overlay include:
- meeting the needs of multi-cultural communities by providing all information in different languages
- providing convenient accessibility options for our users
- although not essential overlays do seem to be useful for some people and gives them the option to customise content to meet their needs in a way that even a WCAG compliant site doesn’t
I was pleased to hear that some councils are actively reviewing their use of overlays and have carried out user testing to ensure that they meet the needs of people with disabilities. Those who are carrying out ongoing user testing have said that they will address any problems as they are encountered. I fear, however, that user testing of overlays may be the exception, rather than the rule.
Accessibility overlays were popular in the 1990s when the knowledge of how to fix and resolve issues was relatively limited. Having implemented an overlay I can fully understand how it may have slipped out of consciousness over time and become a resource that is provided in the background, without being periodically reviewed.
That said I would encourage councils to bring overlays into focus and consider them alongside broader requirements for improving the accessibility of their websites. Every third party application associated with a website needs to be periodically reviewed, however useful it might have been in the past.
I was interested to hear from colleagues in local government that some councils have already reviewed their use of overlays and have decided not to use them any longer. This was as a result of reading about the concerns detailed above, but also because they have found out that those who use assistive technology are likely to use their own rather than using one provided by the council.
A lack of knowledge, skills and resources to meet accessibility might also partly explain why overlays were first introduced by councils. Under pressure to meet accessibility requirements councils looked for what seemed to be immediate and visible solutions to an issue. Overlays were also a way to make a outward facing statement to their residents that they take accessibility seriously. Fixing accessibility issues in the background may be more valuable, but this work is essentially hidden.
Conclusions
Over a quarter of councils in the UK and Ireland are currently using accessibility overlays. Whilst overlays can fix some issues they do not necessarily help councils to meet the legal requirements of accessibility compliance. If your council hasn’t or isn’t already reviewing the use of overlays, then this is a good time to start.
Footnotes
- Overlay Fact Sheet ↩︎
- Scope: Why accessibility overlays do not improve site accessibility ↩︎
- Gina Bhawalkar, Principal Analyst, Forrester: What’s wrong with quick-fix products for digital accessibility ↩︎
- Cheryl Swan, HeX Productions: Setting the record straight: a guide to accessibility overlays ↩︎
- Siteimprove: A guide to accessibility overlays ↩︎
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