A readability checker tool is an online program or application that analyzes a text document and provides an estimate of its readability level.

Readability is a measure of how easy or difficult it is to read and understand a piece of text. It takes into account factors such as sentence length, word length, and vocabulary complexity.

A readability checker tool uses algorithms to analyze a text document and provide an estimate of its readability level. It can provide various measures of readability, such as the Flesch-Kincaid Grade Level, the Gunning Fog Index, and the Coleman-Liau Index.

Using a readability checker tool can help writers and editors assess the readability of their text and make adjustments to improve its clarity and accessibility. It can also be useful for teachers and educators who want to assess the readability of a text for their students.

Readability checker tools are commonly used in industries such as publishing, journalism, and education. They can be especially useful for writers who want to ensure that their work is accessible to a wide audience, including people with different levels of literacy and language proficiency.

In summary, a readability checker tool is an online program or application that analyzes a text document and provides an estimate of its readability level. It's a valuable tool for writers, editors, and educators who want to improve the accessibility and clarity of their text.