# Post readability checker

Paste a social post or caption. The checker scores it with the Flesch reading ease and Flesch-Kincaid grade formulas, lists sentences of more than 25 words and possible passive phrases, and suggests what to change. Hashtags, mentions, links and emoji are not counted as words.

## What the scores mean

Reading ease runs from about 0 to 120: the higher it is, the easier the text. Short words and short sentences push it up. The grade level turns the same counts into a US school grade, so 8 means an eighth grader can follow it. Wikipedia's worked examples come out the same here: "The cat sat on the mat." scores 116, and "The Australian platypus is seemingly a hybrid of a mammal and reptilian creature." scores 37.5 with grade 11.3.

| Reading ease | Level |
|---|---|
| 90 and up | Very easy |
| 80 to 90 | Easy |
| 70 to 80 | Fairly easy |
| 60 to 70 | Plain English |
| 50 to 60 | Fairly difficult |
| 30 to 50 | Difficult |
| 10 to 30 | Very difficult |
| below 10 | Extremely difficult |

## Making a post easier to read

Start with the long sentences the checker lists: any sentence of more than 25 words is hard to take in on a small screen, so split it in two or three. Then swap long words for short ones where the meaning stays the same, such as use for utilize. Passive phrases hide who does what, so try the active form and keep whichever reads better.

A score is a guide, not a rule. A post for developers can use the words they use, and a single line like "Go." scores high without saying much. When the post reads well, paste it into PostBoost to schedule it to all your networks at once.

## How to use

1. Write or paste your post in English.
2. Read the reading ease score and its level, from Very easy to Extremely difficult.
3. Check the grade level: grade 8 or lower suits most social posts.
4. Follow the suggestions: split long sentences and swap passive phrases for active verbs.
5. Copy the improved post into PostBoost to schedule it.

## FAQ

### What is a good Flesch reading ease score for social media?

60 or more. Flesch's own table calls 60 to 70 plain English, easily understood by 13 to 15 year olds, and 70 to 80 fairly easy. Social posts are read fast on a phone, so the higher the better; the checker suggests changes below 60.

### How is the score calculated?

With the published formulas: reading ease is 206.835 minus 1.015 times the words per sentence minus 84.6 times the syllables per word. The grade level is 0.39 times the words per sentence plus 11.8 times the syllables per word minus 15.59. Both are rounded to one decimal.

### How are syllables counted?

By a fixed rule, not a dictionary: each group of one or two vowels is one syllable, after a silent final e, es or ed is dropped. A vowel before a final -ing adds one, as in being. Words of three letters or fewer count one. It matches a dictionary count for most words and can be off by one for a few.

### Do hashtags, links and emoji count?

No. Hashtags, @mentions, links and emoji are not words, so they do not change the scores. The checker counts the emoji and hashtags separately, so you can see them at a glance.

### What counts as a passive phrase?

A form of be (is, was, were, been, being) followed by a word that looks like a past participle, such as was written or is being reviewed. It is a hint, not a grammar check: some matches are fine, so read each one and keep it if an active verb reads worse.

### Does it work for other languages?

Not yet. The formulas and the syllable rule are made for English. For another language the API returns supported false with a note and no scores; the page always checks English.

### Is my text sent anywhere?

No. The checker runs in your browser and nothing you type is sent to PostBoost.

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Last verified: 2026-10-16

## Sources

- [Flesch, R. (1948). A new readability yardstick. Journal of Applied Psychology, 32(3), 221-233](https://doi.org/10.1037/h0057532)
- [Kincaid, J. P. et al. (1975). Derivation of new readability formulas for Navy enlisted personnel. Research Branch Report 8-75](https://apps.dtic.mil/sti/pdfs/ADA006655.pdf)
- [Wikipedia: Flesch-Kincaid readability tests (formulas, score table, worked examples)](https://en.wikipedia.org/wiki/Flesch%E2%80%93Kincaid_readability_tests)

Canonical: https://postboost.co/tools/post-readability-checker