7 Best Readability Checkers Online

When it comes to creating highly-optimized, engaging and unique content online, a readability checker is one tool you can’t afford to be without. By analyzing the linguistic structure of your teRatherxt, a readability checker can tell you whether or not the text is accessible, understandable and well-tailored to your target audience.

When it comes to creating highly-optimized, engaging and unique content online, a readability checker is one tool you can’t afford to be without. By analyzing the linguistic structure of your teRatherxt, a readability checker can tell you whether or not the text is accessible, understandable and well-tailored to your target audience.

To help meet this need, a variety of online readability checkers have sprung up online. With these tools, you can either copy and paste your text, upload a file or add a URL and have the checker analyze your content to determine your readability score. 

Different readability checkers have different methods for analyzing and providing you with this score. In this detailed review, we’ve uncovered the seven best online readability checkers to make it easy for you to create content that’s authentic, easily understood and interesting to read.

7. Hemingway Editor

Hemingway Readability Checker
Hemingway Editor is a basic readability checker that helps you improve your writing

Rather than using a specific readability formula like Flesch Kincaid, the Hemingway Editor looks at a combination of sentence length, use of adverbs and passive voice, paragraph structure and the complexity of the words you use. Through a quick but detailed analysis, it highlights (literally) specific readability issues.

After its analysis is complete, it assigns a score to your writing, as well as a U.S. grade level. The lower the score, the easier your text is to read and understand. Through Hemingway App’s color coded highlighting system, you’ll see precisely what you should change in order to improve your site’s readability. For example, complex and lengthy sentences are highlighted in yellow or red while the use of adverbs and passive voice are marked in blue or purpose respectively. This makes it easy for you to see at-a-glance what needs to be changed. 

Hemingway is available as both an app and as a desktop version for both offline and online use. You can edit your text directly with the built-in editor and the tool will also provide you with formatting suggestions in case you get carried away with the use of bold or italics. It makes accurate suggestions on how to better use features like headings and bullet points to break up long walls of text – a must when catering to online readers. 

6. Readable

Readable Readability Checker
Readable highlights issues in your writing as well as provides you with a grade and grade level assessments  was one of the first online platforms to offer an AI-powered readability checker among its tools. Through the use of NLP (natural language processing) Readable conducts a deep readability analysis, generating a score that’s based on several readability formulas including Flesch-Kincaid, Gunning Fog and Coleman-Liau. 

Because Readable is powered by AI, it takes into account the context and purpose of your content. It knows that if you’re writing a children’s book, for example, that the readability should be at a different level than research aimed at nuclear physicists. As most content falls in the middle of that spectrum, it can provide you with various insights and suggestions to help make your writing more understandable to your target audience. 

As you add text to Readable, it checks your writing in real-time, offering suggestions on alternatives or ways to simplify your writing or improve its clarity or flow. You can also customize its analysis based on specific readability formulas that you want to focus on, as well as who your target audience is, making it more likely to give you relevant suggestions for improvement. 

One of Readable’s more interesting features is the ability to check content across multiple languages. If you translate content or work with multilingual audiences, being able to check readability across languages is a crucial feature to have. 

5. Grammarly

Grammarly Readability Checker
A readability report from Grammarly

As one of the most popular online writing tools, Grammarly also offers a lesser-known feature in the form of a readability checker. Like Readable, it looks at things like word choice, clarity, text structure and sentence length to determine the readability of a given text, assigning a score by using popular formulas like Flesch-Kincaid Grade Level and the Gunning Fog Index. 

Beyond the use of popular readability formulas, Grammarly also provides suggestions to make your content better. If your writing is excessively wordy, for example, or you use a lot of complex sentences, it may offer suggestions on how to make your writing more concise and more accessible to readers. 

Where Grammarly particularly shines is in its approach to improving vocabulary and tone. If your tone is inconsistent or you use too much jargon, it will suggest alternatives that improve the flow and engagement levels of your writing. Through its context-specific writing suggestions, you can get detailed advice on how to tailor your content to a specific audience, be it a blog post, a creative poem or a more formal document. 

4. Readability Formulas

ReadabilityFormulas Readability Checker
An example of a highly technical analysis using several readability formulas

Don’t let its 1990s-style website put you off from trying, It combines several readability formulas including lesser-known options like the Linsear Write Formula and the SMOG Index to give you a well-rounded idea of your document’s readability level. 

If you want to get into the details and formulas behind the formulas, this is the site for you. Not only does it provide you with the mathematical formulas behind each readability score, but it also tells you what the readability test measures and gives you examples of how it's used. For example, the site notes that the U.S. Department of Defense uses the Flesch Reading Ease score for its forms, while the state of Florida requires that any life insurance policies issued in the state have a Flesch-Kincaid score of 45 or better. 

3. WebFX Readability Test

WebFX Readability Checker
The WebFX Readability Test lets you check the readability of a URL or direct text

WebFX offers a free and fully accessible readability test in addition to many other helpful writing and website optimization tools. The readability test spans several different readability formulas including Flesch Kincaid, Gunning Fog, SMOG and many more. Results are displayed as a gauge with the specific formulas as well as more information on how they’re used, displayed on the results page.

WebFX’s readability tool works nearly instantaneously and offers a thorough “grade” of your content so that you can know with greater certainty if it’s too complex or too basic for your intended audience. Unfortunately, although it’s free and easy to use, the tool doesn’t offer any type of plagiarism or AI writing detection like Originality.AI.. It also doesn’t provide you with any concrete tips on how to improve your writing, the way that Grammarly does.

If you need to quickly and easily determine the readability of your content through a variety of formulas, however, it’s an easy and helpful tool to get the job done fast.

2. ProWritingAid

ProWritingAid Readability Checker
The ProWritingAid Homepage

ProWritingAid is a combination spelling and grammar checker, tone and style editor, readability checker and much more. One of its major benefits is that it’s integrated into several different platforms including Microsoft Word, or as a browser extension in browsers like Chrome and Firefox. 

ProWritingAid goes beyond many other similar readability checkers in that it also offers suggestions on your word choice, use of transition words, passive voice and the complexity of your vocabulary. All of these factor into the readability checker, so if you’re trying to write for a specific audience, the tool will identify things like excessive use of passive voice and give you more straightforward suggestions on writing in a more active style. 

Another major benefit of using ProWritingAid is that you can tailor the suggestions to your particular genre, so whether you’re writing fiction, non-fiction, academic writing, blogging or copywriting, you can set the tool to understand the context of your writing so that it can offer your better suggestions. 

However it’s worth noting that many of the suggestions ProWritingAid gives you require a deep knowledge of the English language and things like how prepositional phrases and other details work together, which may be overwhelming if you’re not prepared for the deep learning curve. 

In addition, with the free version of ProWritingAid, you’re limited to checking 500 words or less. While this is fine for a short article, more detailed content may require an upgrade. Additionally, the plagiarism checking feature is only available with the premium version of the tool. 

1.Originality.AI Readability Checker

Originality.AI, well-known for its plagiarism and AI writing detection, also offers a free readability checker.

Originality.AI Readability Checker
The results from the Originality.AI readability checker

In just seconds, Originality.AI’s readability checker can not only give you your reading score from eleven different formulas (more than any of the other readability checkers profiled here), but it can also provide you with your keyword density in terms of 1 and 2-word keywords – a helpful tool if you’re involved in search engine optimization. 

Originality.AI’s readability tool is also free for up to 10,000 words, giving you a much more precise view of your document’s readability than trying to break it up into 500 word chunks. You can also optionally upload a file or add in a URL to check your readability. The tool is also available as a browser add-on. 

With the paid version of Originality, beyond getting your readability score and keyword density, you also have the option of checking your document for plagiarism or AI detection. You can do this on a case-by-case basis or run a document through all of the tests to ensure that it reads in a way that’s authentic and understandable. 

The best part is that the full version of Originality.AI is available for just 1 cent per 100 words scanned, making it an affordable alternative to the high costs of premium readability tools. Try it for yourself risk-free with full pricing transparency: choose to pay-as-you-go with pricing as low as a one-time fee of $30 or a base subscription of $14.95/month. A monthly subscription also gives you access to team management tools, a full site scan, unlimited scan history, the Originality.AI appy and any new features when they’re released. 

Which Readability Checker is Best? 

There is no single “best readability checker” that will tick every box for every user. As you’ve seen in this article, some readability checkers are highly focused on providing you with writing and tone suggestions, others focus more on grammatical use and spelling in addition to readability. Some purely check readability based on existing mathematical formulas and others integrate more closely with the tools you already use and know. 

However, many of these readability checkers are available for free or have a trial option so that you can test them all before you decide. Try out the ones that most closely align to your need for a readability checker and see the results you get. No matter which one you ultimately choose, your content will read better, be more easily understood and clearer for your audience as a result.

Sherice Jacob

Plagiarism Expert Sherice Jacob brings over 20 years of experience to digital marketing as a copywriter and content creator. With a finger on the pulse of AI and its developments, she works extensively with to help businesses and publishers get the best returns from their Content.

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