
Quickly and easily give your content a readability test.
We help you to refine, enhance and simplify. Using powerful readability algorithms like Flesch-Kincaid and the Gunning Fog index, readable.io gives you the most accurate readability scoring available.
We’ll keep you on track.
We’re constantly looking at new ways to provide the best support possible. Our expansive readability knowledgebase ensures you get the most out of ReadablePro. As do our readability how to and best practice guides. Valuable tools for helping you write the best content possible.
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A readability score is a calculated index which can tell you what level of education someone will need to be able to read a piece of text easily.
A number of industry-leading algorithms is used by readable.io to measure readability scores. Factors considered include:
Flesch Reading Ease will tell you what level of education someone will need to be able to read a piece of text easily.
The Reading Ease formula generates a score between 1 and 100. A conversion table is then used to interpret this score. For example, a score of 70-80 is equivalent to school grade level 7 and should be fairly easy for the average adult to read.
In the mid 1970’s the Flesch Reading Ease was amended so that it could be used by the US Navy. From those changes and enhancements, the Flesch-Kincaid Grade Level was created.
Flesch-Kincaid Grade Level classifications are based on:
Gunning Fog index is principally used as a tool to help writers keep their texts clear and simple. Developed by Robert Gunning Associates in 1944, experienced newspapers and publishing consultants,
The Gunning Fog formula generates a grade level, typically between 0 and 20. The formula estimates the years of formal education the reader requires to understand the text on first reading.
So, if a piece of text has a grade level readability score of 6 then this should be easily readable by those educated to 6th grade in the US schooling system, i.e. 11-12 year olds.
Developed in 1975, the Coleman-Liau Index remains one of the most commonly used readability formulae. It scores on understandability and approximates the US grade level needed to comprehend the text.
A distinctive feature of the Coleman-Liau Index is that the formula doesn’t involve any counting of syllables. Instead, it was designed to easily calculate text by concentrating on characters per word.
Automated Readability Index is designed to gauge the understandability of a text and aligns it to the US grade level.
CEFR – the Common European Framework of Reference for Languages – was developed as a tool for employers and educational bodies to evaluates language skills.
CEFR gives writers a clear picture of their contents readability level. Helping you talk to your audience in clear and effective ways.
The underlying message with CEFR is one that is core to readability and the CEFR scale helps focus content on the correct people.
SMOG is the fantastic anacronym for Simple Measure of Gobbledygook.
The SMOG algorithm estimates the number of years of education a reader needs to be able to understand your piece of writing.
“SMOG should be the preferred measure of readability when evaluating consumer-oriented healthcare material.”
– Journal of the Royal College of Physicians of Edinburgh

For grade levels, the result of most of the scoring algorithms, the score corresponds roughly to the number of years of education a person has had – based on the USA education system.
A grade level of around 10-12 is roughly the reading level on completion of high school. Text to be read by the general public should aim for a grade level of around 8.

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