retext-readability

retext plugin to check readability.

What is this?
When should I use this?
Install
Use
API
- unified().use(retextReadability[, options])
- Options
Messages
Types
Compatibility
Related
Contribute
License

What is this?

This package is a unified (retext) plugin to check readability: whether your presumed target audience can read your prose. It applies Dale—Chall, Automated Readability, Coleman-Liau, Flesch, Gunning-Fog, SMOG, and Spache.

When should I use this?

You can use this plugin when you’re dealing with content that might be difficult to read to some folks, and have authors that can fix that content.

💡 Tip: I also made an online, editable, demo, similar to this project: wooorm.com/readability.

Install

This package is ESM only. In Node.js (version 16+), install with npm:

npm install retext-readability

In Deno with esm.sh:

import retextReadability from 'https://esm.sh/retext-readability@8'

In browsers with esm.sh:

<script type="module">
  import retextReadability from 'https://esm.sh/retext-readability@8?bundle'
</script>

Use

Say our document example.txt contains:

The cat sat on the mat

The constellation also contains an isolated neutron
star—Calvera—and H1504+65, the hottest white dwarf yet
discovered, with a surface temperature of 200,000 kelvin

…and our module example.js contains:

import retextEnglish from 'retext-english'
import retextReadability from 'retext-readability'
import retextStringify from 'retext-stringify'
import {read} from 'to-vfile'
import {unified} from 'unified'
import {reporter} from 'vfile-reporter'

const file = await unified()
  .use(retextEnglish)
  .use(retextReadability)
  .use(retextStringify)
  .process(await read('example.txt'))

console.error(reporter(file))

…then running node example.js yields:

example.txt
3:1-5:57 warning Unexpected hard to read sentence, according to 4 out of 7 algorithms readability retext-readability

⚠ 1 warning

The default target age is 16. You can pass something else, such as 6:

   .use(retextEnglish)
-  .use(retextReadability)
+  .use(retextReadability, {age: 6})
   .use(retextStringify)

…then running node example.js again yields:

example.txt
1:1-1:23 warning Unexpected hard to read sentence, according to 4 out of 7 algorithms readability retext-readability
3:1-5:57 warning Unexpected hard to read sentence, according to all 7 algorithms      readability retext-readability

⚠ 2 warnings

API

This package exports no identifiers. The default export is retextReadability.

`unified().use(retextReadability[, options])`

Check hard to read sentences.

Parameters

options (Options, optional) — configuration

Returns

Transform (Transformer).

`Options`

Configuration (TypeScript type).

Fields

age (number, default: 16) — target age group
minWords (number, default: 5) — check sentences with at least this number of words; most algos are made to detect the reading level on an entire text; this plugin checks each sentence on its own; for short sentences, one long or complex word can strongly skew the results
threshold (number, default: 4 / 7) — number of algos (out of 7) that need to agree something is hard to read

Messages

Each message is emitted as a VFileMessage, with source set to 'retext-readability', ruleId to 'readability', actual to the difficult sentence, and expected to an empty array.

Types

This package is fully typed with TypeScript. It exports the additional type Options.

Compatibility

Projects maintained by the unified collective are compatible with maintained versions of Node.js.

When we cut a new major release, we drop support for unmaintained versions of Node. This means we try to keep the current release line, retext-readability@^8, compatible with Node.js 16.

retext-syntax-mentions — classify @mentions as syntax
retext-syntax-urls — classify URLs and filepaths as syntax
retext-simplify — check phrases for simpler alternatives

Contribute

See contributing.md in retextjs/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.

retextjs/retext-readability