LineHighlight – a tool for persons with dyslexia

LineHighlight is a simple open source bookmarklet for persons with dyslexia that highlights (in yellow) the text line the user clicks on in a web browser. It has been developed by Erik Zetterström and funded by ICT Enablers.

It is intended as a tool primarily for persons with dyslexia, but can be useful for other purposes as well.


Browsers supported: ChromeFirefoxOperaSafari

Drag this button to your bookmarks bar:

When you wish to use it, just click on the bookmark. You will see a little yellow box saying “LineHighlight” in the lower right hand corner when LineHighlight is active.

If the button does not work in your browser, manually make a new bookmark called “LineHighlight” with the following address:


Bugs and known issues

LineHighlight runs on the latest Firefox, Google Chrome, Opera and Safari browsers. Internet Explorer and Edge are not supported because they lack support for the selection.modify() function.

When clicking on for example bold text in the middle of a row only the bold text will be highlighted because the selection method sees the bold tags as line boundaries. Keep in mind that the software is just released, so there are surely bugs. Bug reports and feature requests are most welcome.

Envisioned features

Given free time and funds these are the top 3 features I would like to add to LineHighlight.

  • Enabling the user to click a word on the highlighted line to get a small information window with a small picture and text from Wikipedia or Wikitionary.
  • Text to speech of the highlighted line.
  • Microsoft Internet Explorer compatibility, ideas anyone?


LineHighlight is open source software licensed under the MIT License.

Support and liability

ICT Enablers can not guarantee any user support for this product. As stated in the MIT License ICT Enablers or Erik Zetterström can not be held liable for any claim, damages or other liability arising from use of LineHighlight.

Source code

Source code for LineHighlight is available on GitHub.