This is the plainest of the AI checks and, perhaps because of that, one of the higher-scoring: it does not ask what the page says, only how it is built. Sentence length, paragraph length, vocabulary complexity, rhythm. Most sites write reasonably plainly without trying, which is why the median sits comfortably above the middle of the dataset — and why the pages that fail here tend to fail badly rather than marginally.
Here is where that sits. The median is 75/100, which ranks it 8 of the 25 measures in this dataset. The middle half of results falls between 58 and 83 — a band 25 points wide. That is wide: sites genuinely diverge here, which is to say getting ahead is still possible.
How the scores are distributed
An average on its own misleads. The chart below splits all 1,002 scans into five score bands, totalling 100%. A large group clears the top band while a real tail is left behind, so the median understates how well the leading pages do.
- 0–19
- 20–39
- 40–59
- 60–79
- 80–100
| Score band | LLM Readability |
|---|---|
| 0–19 | 0% · 0 |
| 20–39 | 3% · 28 |
| 40–59 | 25% · 251 |
| 60–79 | 27% · 269 |
| 80–100 | 45% · 454 |
| Total runs | 1,002 |
The grade mix
The same data as letters: A+ 95–100, A 85–94, B 75–84, C 65–74, D 50–64 and F below 50.
Where your score stands
A high score is not a compliment about your prose and a low one is not an insult. This measures machine-parseability, and the two occasionally diverge: dense, subordinate-clause-heavy writing can be a pleasure to read and genuinely hard to chunk. If you score badly and your readers do not complain, the fix is structural — break the long sentences, keep the voice.
| Tool | 10th | 25th | Median | 75th | 90th | Mean | Lowest | Highest |
|---|---|---|---|---|---|---|---|---|
| LLM Readability | 53 | 58 | 75 | 83 | 94 | 73.2 | 23 | 100 |
How to read it: 58 is bottom-quartile, 75 is a typical page, 83 starts the upper quartile and 94 or above is the top 10%. These thresholds apply to this tool only.
The checks that fail most
The failures cluster around length: sentences that run past the point where a parser loses track of the subject, and paragraphs that never break. There is a secondary group about variety — writing where every sentence is the same length reads as machine-generated to a machine, which is a pleasing irony but also a real signal.
| Check | Did not pass | Weight |
|---|---|---|
| Has a summary / TL;DR | 94% | Partial |
| No very long sentences (>40 words) | 70% | Hard fail |
| Ideal average sentence length | 35% | Hard fail |
| Few long sentences (>28 words) | 33% | Partial |
| Uses lists | 19% | Partial |
| Broken into paragraphs | 10% | Partial |
| Reasonable average word length | 9% | Partial |
| Healthy lexical variety | 9% | Partial |
| Self-contained short passages | 7% | Partial |
| Varied sentence rhythm | 6% | Partial |
| Low share of long/complex words | 1% | Partial |
“Hard fail” means the check’s full weighting is lost; “partial” means only part of the score is. Rates are the share of scans in which the check ran and did not pass.
The weakest areas
This tool groups its checks into categories. The chart below shows how often each category was the lowest-scoring one in a scan — which area is most often the weak link. It is not the average score in that category; it is how often it came last.
“Rhythm & Directness” was the weakest area in 56% of scans.
What to fix first
Split the longest sentences on the page and nothing else, then re-run. Sentence length dominates this score, and halving three or four of the worst offenders usually moves it more than any amount of vocabulary simplification. Long sentences are also where ambiguity hides for human readers.
A typical scan passes 8.1 of 11 checks and leaves 2.9 open items behind. What drags a score down is usually not one catastrophe but accumulated small omissions.
Run the LLM Readability Score on your own page
Month by month
The figures on this page are replaced at every refresh. At the end of each month a permanent edition is published for that month and never edited again — which is the only reason this series can be compared at all. One edition has been published so far; when the second lands this section will set the two months side by side.
| Edition | Median | vs. previous | Scored 80+ | Issues/run | Runs |
|---|---|---|---|---|---|
| August 2026 | 75 | baseline | 45% | 2.9 | 1,002 |
Frequently asked questions
Does simpler writing actually help with AI search?
It helps with the mechanical part of it. A model that has to segment a page into passages does that more reliably when the boundaries are clear, and a clean segment is more likely to be quoted accurately. It does nothing for whether your argument is right or your information is worth having — plain writing makes good content usable, it does not make weak content good.
What sentence length should I aim for?
Around twenty words on average, with genuine variation around it. The average matters less than the tail: one forty-word sentence does more damage than a slightly high mean, because that is where a parser loses the subject. Varying deliberately between short and medium reads better to a person too.
Is this the same as a Flesch reading-ease score?
Related but not the same. Flesch is calibrated to human reading difficulty using syllables and sentence length. This adds the things that matter to a machine specifically: whether passages are self-contained, whether the page is chunked into retrievable units, and whether structure marks where one idea ends and the next begins.
What is a good score on the LLM Readability Score?
In this dataset the median is 75/100, so scoring 75 puts you exactly in the middle. 83 is the start of the upper quartile and 94 or above is the top 10%; below 58 is the bottom quarter. Those thresholds are specific to this tool — the 25 measures in this dataset have very different medians, so 70 here and 70 elsewhere do not mean the same thing.
Which check fails most often on the LLM Readability Score?
“Has a summary / TL;DR”, which did not pass in 94% of scans. The costliest failures, though, are the ones scored as hard fails — this tool has 2, the most common being “No very long sentences (>40 words)” at 70%.
Questions that govern the whole series — how the sample is collected, how sites are anonymized, how often the figures are refreshed — are answered in the methodology on the hub.
Using this data
The figures, tables and charts on this page are free to reuse under CC BY 4.0; the only condition is a link back to this page. Suggested citation: SeoMods — LLM Readability Score benchmarks, 2 September 2026, https://seomods.com/seo-score-benchmarks/llm-readability-score. If you need to cite by date, use the August 2026 edition instead: this page changes at every refresh and that one never does.