Flesch Reading Ease: Does It Matter for SEO? (Data Study)

But how much attention should you pay to it? What is it really good for? Can a better readability score help you rank better?

In this article, you’ll learn the answers to these questions with conclusions backed up by our mini-study of 15,000 keywords.

But before we get to the nitty gritty, let’s make sure we’re on the same page.

1. What is Flesch Reading Ease?
2. Does Flesch Reading Ease score affect Google rankings?
3. Should you optimize your content based on the Flesch Reading Ease score?
4. Notes about methodology

Flesch Reading Ease (FRE) is a way to score the readability of text. The scores range between 1 and 100, with higher scores deemed easier to read.

Here’s the Flesch Reading Ease score formula:

You’ll probably never need to calculate this yourself but keep in mind its two variables: the length of your sentences and words. The longer your words and sentences are on average, the lower your FRE score.

In 2018, John Mueller from Google said he’s not aware of any algorithms that use basic readability scores. And since FRE is pretty basic with just two variables at play, it wouldn’t really make much sense to use it. So no, readability scores like FRE don’t directly affect rankings.

This is backed up by our study of 15,000 keywords, which found virtually zero correlation between rankings and FRE scores.

So then, why do so many SEO and content tools show this score?

The answer is because FRE is a proxy for readability, and readability is obviously important. It can influence user experience—something that’s become more and more important in SEO over the years.

If searchers find your content hard to read and understand, they’ll probably leave. This leads to negative user experience signals like a low dwell time, time on page, and a high bounce rate, which may signal to Google that your page isn’t a great result.

Even worse, because fewer visitors actually end up consuming the content, fewer people will link to it—and we know that backlinks are one of the most important ranking factors.

Given that readability is important, it probably seems as though you should optimize your content if your FRE score is too low, right?

Not exactly because that would be detrimental to some topics.

For example, consider a technical topic like the one you’re reading now. There’s no way to talk about Flesch Reading Ease and SEO without using a few complex words. If we tried to “optimize” this article for readability by replacing complex words with simpler ones, we’d just make things harder to understand.

There’s also no reason to do this because this is not an article aimed at the masses. Our target keyword is “flesch reading ease” which gets an estimated 4,900 monthly searches in the US:

You’re reading this now so it’s clear that you have a higher than average reading comprehension level and are comfortable with a few big words here and there.

That said, if you’re writing about a more mainstream topic that is likely to appeal to people with varying levels of reading comprehension, aiming for a higher FRE score can be a good idea.

But here’s the thing: That’ll probably happen naturally because you’re less likely to use long, complex words and sentences if you’re writing, say, a pancake recipe.

This is probably why the average FRE score for the top 10 results in Google varies dramatically by topic, as we found in our mini-study:

You can see that average FRE scores decrease based on the complexity of the topic:

Food (simple topic): 69.7 on average, i.e., fairly easy to read

Marketing (medium topic): 60.2 on average, i.e., standard reading level

Engineering (complex topic): 49.6 on average, i.e., difficult to read

It’s clear that people who write about food-related topics don’t put more effort into “optimizing” their readability than those who talk about engineering. It’s just that food is a simpler topic.

What does this all mean in practice?

The results of this study confirm that there’s no readability score threshold that would be applicable to all types of content. We all inherently use different vocabulary based on the topic and target audience.

All this being said, here are six content writing tips related to readability scores:

1. Don’t blindly pursue “perfect scores” in SEO and content tools.
2. Understand your audience and write for them.
3. Keep a good reading flow. Use short sentences but don’t be afraid to throw in a complex one here and there.
4. Don’t make things more complicated than they need to be.
5. Read it out loud when editing. It helps to spot issues you’d normally overlook.
6. Have someone else proofread your text and provide feedback.

To wrap this up:

As long as you stick to solid writing practices, readability scores don’t matter for SEO. Great valuable content does.

Don’t follow recommendations that tools give you based on the scores alone. The only time I’d suggest reevaluating your content upon a readability score is when it differs significantly from your usual scores.

I selected a sample of a few big websites focused on engineering, marketing and food topics. Using the Organic Keywords report in Ahrefs’ Site Explorer, I then exported a sample of keywords with varying monthly search volume ranges where each domain ranked in the top 10. This was done for English keywords in the US only:

This Organic Keywords report shows 500 keywords that ahrefs.com ranks for in the top 10 with at least 1,000 monthly searches in the US.

I used different search volume ranges to make sure the samples included both fat-head and long-tail keywords in each category. The keywords were unique and any obvious brand keywords were removed.

We ended up with 5,000 keywords in each category, which means we analyzed 15,000 keywords and SERPs in total. Some pages (19% in engineering, 9% in marketing, 10% in food) were excluded from the study because it wasn’t possible to reliably calculate the Flesch Reading Ease score for them.

Got any questions? Ping me on Twitter.