Frequency Level Checker: Easily check the lexical level of a text

frequency checker

As an English language instructor, I am always on the hunt for reading and listening material that I can use in my classroom. As simple as that sounds, it is always a tricky endeavor simply because most of the material created is meant for someone fluent in the language and makes use of a larger lexicon than language learners have.

While there are a number of tools that provide reading level scores such as Gunning-Fog and Flesch-Kincaid, these are designed for native speakers and are connected to student grade levels. They take into account sentence complexity and paragraph length along with vocabulary density, but don’t give an indication of what words, phrases, or idioms that increase the difficulty.

A few years ago, I came across a rather simplistic looking tool that has really helped me out over the years to find and edit text for my students that fits within their vocabulary level. Here is how it works:


  • Find a text you would like to check and paste it into the box at the top of the page.


  • You will find five options below the text box.
    • Level 1 = the main 1000 words we use in general English.
    • Level 2 = the next 1000 words we use in general English.
    • Level 3 = the 800 most used words in academic English.
    • Outside Levels = words not in the above three levels. Proper names fall under this category since they are not in the vocabulary lists.
    • Symbols = anything that is not a letter (eg. punctuation, numbers).
  • There are a few options on using the colour coding system:
    • Select the colour of the text for each of the levels by clicking on appropriate radio button. I tend to leave everything black that is not what I want to find and make the one or two levels in colour that I want to highlight. For example, if I am trying to find words for my intermediate level class that may be difficult for them, I select black for Level 1 and for Symbols, but make Level 2 red, Level 3 green, and Outside Levels blue.
    • If you want to only see words from a specific level or levels, you can hide everything else by choosing ‘Invisible’ for those levels you want to hide. This is helpful when you are building a glossary or are looking for lower level synonyms for simplifying/altering the text.
  • Once you have chosen your colour options, click on ‘Enter’ and a new window or tab opens up with three areas.
    • The main area in the top-left has the text in the colours you have chosen.
    • Along the bottom, you have the totals and percentages for each category, including word families. This is helpful for seeing what percentage of the text your students should know. Keep in mind you want the percentage to be pretty high (~95%) for fluency and for figuring out words from context.


I hope that helps. Let me know what you think!


  1. hi Nathan

    online vocab profilers are great though they do have a tendency to be inaccessible at times e.g the lextutor one. is this one u describe prone to this?

    a good offline one is antwordprofiler [], this also allows you to edit the text


  2. Nathan – I am redesigning my curriculum to make it fit into the PBLA delivery model and I am stuck trying to find appropriate reading materials for my levels (CLB 6-7-8). Your article really opened my eyes and made me look closely at the realia I had been using in my classroom. As it turns out, my material is too high for my levels – averaging a grade 11-12 on Flesch-Kincaid. My question to you is, how do you marry up the CLB levels with the grade levels? In my school board, ESL learners can go to high-school credit when they achieve “CLB 7”. That should roughly be equivalent to a Grade 8, right? So, then moving down the scale, achieved CLB 6 would be able to read Grade 7, and so on. What are your thoughts on this?

    (Oh, I went into the CLB reading exemplars because I was curious, and tested the reading level of their CLB 6/7 “complaint letter”. It had an average grade level of 11.1)

    • Thanks for the comment and question, Jen. It is a tricky one with the Flesch-Kincaid and the CLB levels. They don’t use the same things to calculate, so the numbers don’t match up all of the time. There are very general ideas, but even then it can be deceptive. In very general terms:
      CLB 6 -> FK 8-9
      CLB 5 -> FK 6-7
      and so on. Really, it isn’t a good determiner, but if the numbers are way off, then you know it doesn’t match your students’ level.

      There is an paper that you might find interesting using various tools to measure CLB reading complexity. It is a PDF found here:
      You might also find this article interesting as well:

      I hope that helps!

      • Thanks – I will look into it. I started putting some of the CLB exemplars into the Flesch-Kincaid, and it came up with some results that were way off; it rated a shopping list for CLB1 as a grade 10, probably because it contained “spinach” and”tomato”.

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