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  • Writer's pictureNatalie Adler Skarzynski

Readability, Exposed: Is Perfectly Readable Perfectly Boring?

In marketing, everything we do starts with the written word. But how do we know what words to write? In Making Websites Win, Dr. Karl Blanks and Ben Jesson explain what makes a successful website. One of the important factors they examine is readability: "[...] Visitors can't buy what they can't understand." Readability is the concept that text should be easy to understand. Some basic rules include writing in short, clear sentences and omitting needless words.

The basis for this is scientific. People have a "memory buffer." As we read, our brains store words in short-term memory. Once we understand the sentence's meaning, the buffer starts over with the next set of words.

But this buffer is small: only about 15 words. Periods and commas can provide stopping points where readers can catch their breath.

The authors suggest using readability checkers to analyze your text. (And we'll dive into this later.)

That's all well and good, but how does the concept of readability square with eloquent writing? Blanks and Jesson also recommend The Elements of Eloquence by Mark Forsyth. (One of my favorite authors.) Here's what Forsyth says in the conclusion of the book: "I hope I have dispelled the bleak and imbecilic idea that the aim of writing is to express yourself clearly in plain, simple English using as few words as possible. This is a fiction, a fib, a fallacy, a fantasy and a falsehood." So what's a copywriter to do?

We must find a middle ground between these two concepts. It's vital to strike a balance between being easy to read and being memorable. Let's start with readability. More specifically, with readability checkers...

Writing Readable Copy: The Master List of Readability Factors

Here are the readability checkers I evaluated:

Why bother figuring out how various tools grade readability? Once you know the rules, you can learn when to bend them.

These checkers take into account:

Note that not all readability checkers consider all these factors. Below, you'll find explanations of each one. And because I was curious, I also checked this post against each of these factors.

Flesch Reading Ease Score

The Flesch Reading Ease Score is one of the most common ways to check readability. Flesch Reading Ease grades writing on a scale of 1-100. Rudolph Flesch devised the score in the 1940s to make newspapers easier to read.

The average adult would find a score of 70-80 easy to read. A score in this range is on par with an 8th-grade reading level.

This post received a Flesch Score of 67.8.

Grade level

That brings us to grade levels, another popular readability metric. There are many variations, but all measure the grade level at which a person would find the text easy to read.

For example, a text rated as 5th grade would be easy for anyone in 5th grade and up to read. The higher the grade level, the more education the reader would need to have.

Here are some common grade level formulas (which, for some reason, all sound like law firms):

  • Flesch-Kincaid: Created in the 1970s based on Flesch Reading Ease. This model matches Flesch scores to grade levels. This post: Grade 5.9

  • Dale Chall: Based on a set of 3,000 common words that any 4th grader would understand. The more vocabulary your text uses outside this set of 3,000 words, the higher the grade level. This post: Grade 11-12

  • Gunning-Fog: Measures grade levels from 0-20. A grade of 8 is appropriate for the general public, where a grade 17+ is above a college graduate level. This post: Grade 7.8

For marketing copywriters, the grade level evaluations bring up an important question. Are we writing for the general public? If so, we'd look for our copy to have a grade of 8 or 9. Or are we writing for a demographic that has graduated high school? College? Beyond?

Grade level metrics are only that – metrics. They provide a yardstick. But it's still up to you to define the goal.

And you'll notice variation between these 3 metrics. Why such a large discrepancy? As you'll see later on, I bring in some literary terms I'm certain no 4th grader would know. Depending on how the grade level metrics assess complexity, they may or may not reflect that.

Sentence length

The rules of readability say short, clear sentences appeal to the broadest audience. How long is too long? Here's what the readability tools I tested considered "long:"

  • Hemingway: 25+ syllables

  • Readable: 30+ syllables

  • SEMrush: 20-25 words

  • Yoast: 20+ words (75% of sentences should be 20 words or fewer)

You'll notice some measure by syllables and some by words. But they all fall in the 20-30 range, with Yoast even giving writers a break on longer sentences.

0.9% of the sentences in this post are more than 25 syllables.

example of readable readability checker
Readable flagged Forsyth's quote from the introduction.

Word length and complexity

How do you tell if a word is complex? The Dale Chall formula would say, if a 4th grader understands it, it's not complex. But most readability checkers I tested look only at the number of letters. So, how many letters does a "long" word have?

  • Readable: 12+ letters

  • SEMrush: 12+ letters

Interesting: the word "readability" squeaks by this test at 11 letters.

0 words in this post have more than 12 letters.

Paragraph length

Some readability checkers flag paragraphs as "too long." How do they define this?

  • SEMrush: 75-85 words seems to be the cutoff

  • Yoast: A good paragraph is between 2 sentences and 200 words

That's a big difference. I am a fan of the shorter paragraph, as it's easier for readers to skim.

0 paragraphs in this post have 75+ words.

Passive vs. active voice

This one takes me straight back to grade school. A quick refresher:

  • Active voice is when the subject of the sentence acts on the verb, e.g. "the boy bought the basketball."

  • Passive voice is when the verb acts on the subject, e.g. "the basketball was bought by the boy."

Sentences in active voice are generally more concise and more desirable for writing. But there are times where passive voice makes sense in context.

Readability checkers give a threshold for the number of sentences using passive voice:

  • Hemingway: 20% of sentences

  • Readable: Flags all uses of passive voice but does not make a recommendation

  • Yoast: 10% of sentences

0.4% of sentences in this post use passive voice.

hemingway readability checker
Hemingway flagged this usage of passive voice. Look familiar?


Adverbs add context to a verb, e.g. "we went quickly" or "the storm arrived suddenly." It seems odd to me, but readability checkers seem to have a problem with our friend the adverb:

  • Hemingway: 1% or fewer of all words should be adverbs

  • Readable: Flags all adverbs

So why the adverb hate? The two checkers that flag adverb use are consistent in this. Hemingway recommends using a "forceful verb" instead of an adverb. Readable explains: "Adverbs are worth avoiding where possible," advising us to replace them with "more active verbs."

0.1% of words in this post are adverbs.


It's plain as the nose on your face: when it comes to elements of writing, I'm like a kid in a candy store. But using clichés in writing sets my teeth on edge and grind my gears. Every cloud has a silver lining, though... (See what I did there?) The Readable checker flags all clichés so you can remove these overused expressions. Clichés can be annoying to readers and make the writing seem unimaginative. This post has 0 clichés – not including the 5 I used in the section introduction to prove my point.

Variety of consecutive sentences

Yoast looks at the number of consecutive sentences that begin with the same word. For example: "Then I went to work. Then I went to the store. Then I went to the park."

It's best to avoid starting sentences with the same word or phrase. Why? Because it's repetitive. This post has 0 consecutive sentences starting with the same word(s), except for the example above.

Subheading distribution

Again, Yoast was alone in measuring this. They recommend breaking up text with a new subheading (H2, H3, etc.) every 300 words. This post passed Yoast's test on subheading distribution.

yoast readability plug in for wordpress
Yoast's scores on various readability elements. I love seeing those green circles!

Transition words

Yoast stood alone in this one, as well. They recommend using transition words in 30% or more of the text's sentences. Examples of transition words include: and, but, so, because, as a result. 27% of sentences in this post use a transition word. I called it good enough.

Bonus: Headline Analyzer

When writing headlines, I often use CoSchedule's Headline Analyzer. This tool measures:

  • Balance of words: common, uncommon, emotional, and power words

  • Headline type: question, list, statement, etc.

  • Sentiment: positive, negative, or neutral

  • Word count

  • Character count

  • Skimmability: what are first three words and the last three words, which users tend to read when they skim

It combines these elements to create a score between 0 and 100. I take the score with a grain of salt, but it's a great tool to compare different headline variations. This post's title scored 72/100.

headline analyzer results
The score and the word balance for this title

Writing Memorable Copy: What Makes Copy Eloquent?

Now we've taken a deep dive into readability metrics. So let's return to the fundamental question I posed at the start of the article. Are the principles of writing memorable copy and writing readable copy at odds? They don't have to be. In The Elements of Eloquence, Forsyth explains the mechanics of a memorable phrase. He cites examples from poetry, prose, song lyrics, and more. So what makes a turn of phrase memorable? Rhetorical figures.

Forsyth covers familiar figures of rhetoric, like alliteration, as well as the obscure, like scesis onomaton. (The names get a little crazy, but what do you expect from classical Greece...)

What does all this have to do with marketing copy? To see how rhetorical figures influence marketing, I looked at 5 famous slogans. Whether intentional or not, many classic slogans rely on these figures of speech. Here are some examples:

"Think Different." - Apple

Rhetorical figure: enallage

Enallege (pronounced e-NALL-aj-ee) is using unusual grammar to make a point. This is at play in the most memorable line of Joseph Conrad's Heart of Darkness: "Mistah Kurtz—he dead." The incorrect grammar stands out to the reader. Here, Apple has taken the phrase, "think differently," and purposefully constructed it incorrectly. As a result, it's more memorable.

"Plop plop, fizz fizz." - Alka-Seltzer

Rhetorical figure: epizeuxis

Epizeuxis (ep-ee-ZOOX-is) is when you repeat the same word in the same sense. Another well-known example is the first rule of real estate: location, location, location. In the case of Alka-Seltzer, epizeuxis certainly makes it memorable. And some speculate it prompted customers to use two tablets when one would have done the trick!

"Save Money. Live Better." - Walmart

Rhetorical figure: isocolon

Isocolon is when two clauses are parallel in their structure and grammar. A famous example: Muhammad Ali's "Float like a butterfly, sting like a bee." I've noticed many brands using isocolon in advertising, from billboards to banner ads.

"What's in your wallet?" - Capital One

Rhetorical figure: anacoenosis

Anacoenosis is a type of rhetorical question. It sets up the question for a particular audience to answer in a certain way. Often used in marketing and politics, it inspires the audience to agree with the speaker. This rhetorical question sets up the answer for the audience. It prompts them to think, "I should have a Capitol One card in my wallet."

"The Few. The Proud. The Marines." - US Marine Corps

Rhetorical figure: scesis onomaton

Scesis onomaton (SKEE-sis o-NO-mat-on) is when a sentence does not have a main verb. Think of, "Space: the final frontier." It's best used to set a scene or state an eternal principle. Without a verb, it's not tied down to a timeframe.

Because it can also bring a sense of nobility, it's a perfect match for the message the USMC is trying to convey. These examples prove that memorable writing and simple writing can be compatible. Writing can be both easy to understand and eloquent. In fact, I'd argue that the best writing is both. Have you graded your marketing copy for readability? Have you used, whether on purpose or not, any of the above rhetorical figures?


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