⌘ K
Flesch · Flesch-Kincaid · Gunning · SMOG · ARI

Markdown Readability Score

Calculates five industry-standard readability metrics on your Markdown content — stripping fences, link URLs, and HTML so the result reflects prose only.

Readability Score
Reading ease
0.0
Very hard
FK Grade
0.0
US grade
Words
0
0 sentences
Complex
0
3+ syllables
input · markdown
output · scores
Flesch Reading Ease
0.0
0 (hard) – 100 (easy)
Flesch-Kincaid Grade
0.0
US grade level
Gunning Fog Index
0.0
Years of education
SMOG Index
0.0
Years of education
ARI
0.0
US grade level
Quick Start

How to score readability

Paste Markdown and get five readability metrics — one is friendlier than the others; check them together.

  1. 01

    Paste Markdown

    Code blocks and link URLs are stripped before scoring.

    Parsing runs through marked with GFM extensions enabled — tables, task lists, strikethrough, and fenced code blocks all match GitHub’s rendering.

    mdGFMmarkedCommonMarklive
    input · markdownmd · GFM
    # Article
    loaded · GFMGFM · ready
  2. 02

    Read Flesch

    0-100 scale; higher = easier. 60-70 is plain-language standard.

    Soft-break behaviour is configurable: by default a single newline becomes a space (CommonMark), toggle on for chat-style <br> insertion.

    scoresoft-breaksoptionsconfiglive
    FRE · options72 · live
    Easy
    options applied · livelive
  3. 03

    Grade levels

    FK / Gunning / SMOG / ARI give a US grade-level estimate.

    The preview is scoped under a .mde class so its CSS doesn’t bleed into the rest of the page. Output HTML is whitespace-controlled for clean diffs.

    gradepreviewscoped CSSrenderstable
    FK · rendered8.5 · ready
    grade 8-9
    rendered · liverendered
  4. 04

    Revise

    Shorter sentences + simpler words → lower grade, higher ease.

    Export covers both raw Markdown and rendered HTML; downloads stream as text/markdown or text/html via Blob + object URL.

    tuneclipboard.md.htmlblob
    ✓ · exportedready · done
    ✓ Done
    shipped · ready to shipsuccess
Pro tips

Author Markdown that renders everywhere

GFM is the safe default

GitHub-Flavored Markdown is the de-facto baseline (tables, task lists, strikethrough). CommonMark is stricter but ubiquitous as a fallback.

Soft-break behaviour varies

A single newline is a space in CommonMark, a <br> in GFM. Toggle soft breaks when source matters.

Escape inside code fences

Backticks inside fenced blocks need a longer fence — three becomes four. Use ~~~ if your content has many backticks.

Anchors are slugified

GitHub lowercases, strips punctuation, and joins with hyphens. Duplicate headings get -1, -2 suffixes.

Tables need a header row

The dash row sets alignment (:---, :-:, ---:). Use Table Aligner for diff-friendly columns.

Front matter is YAML

Triple-dash blocks at the top of files are parsed by static-site generators. Use the Front-Matter Validator to catch syntax errors.

Related toolsWord CounterStyle CheckerEditorLinterMD to textREADME
Use Cases

When to score readability

Docs, marketing, education.

Developer docs

Keep API reference at grade 9-10 max. Render path uses marked with GFM extensions enabled (tables, task lists, strikethrough, autolinks), so what you preview matches what GitHub publishes bit-for-bit. Soft-break behaviour is configurable for chat-style vs prose Markdown.

GFM-compliant

Marketing copy

Aim for Flesch 70+ on landing pages. Pairs cleanly with the Markdown Cheatsheet for syntax you can't quite remember — callout blocks, footnotes, definition lists. Output stays diff-friendly so style-only changes don't drown out real edits in PRs.

GitHub-perfect

Educational content

Match material to your target grade level. Cross-platform safe: anchors, code fences, and tables behave identically on GitHub, GitLab, Bitbucket, and Gitea. Heading-anchor slugs follow GitHub's lowercase-and-hyphenate rules so deep links survive a docs migration.

diff-friendly

Onboarding flows

Simpler language = faster comprehension. No server roundtrip — perfect for proprietary content you can't paste into a public tool. The full marked + GFM bundle ships with the page, so it works offline once loaded.

render-stable

Legal / policy

Reduce jargon to required minimum. Front matter (YAML / TOML / JSON) passes through unchanged so static-site pipelines (Jekyll, Hugo, Astro, Eleventy) read it correctly. Pair with the Front-Matter Validator to catch syntax errors before deploy.

cross-platform

Localisation

Lower grade = easier to translate. Output is reproducible: identical input always produces identical Markdown, so doc-generation scripts can rely on it for snapshot tests and embedded into release workflows.

i18n
FAQ

Frequently asked questions

Use Flesch Reading Ease + Flesch-Kincaid Grade together — they're the most established. Others corroborate.
A heuristic vowel-group counter — fast and accurate enough for prose; not perfect for jargon or names.
Three or more syllables (Gunning Fog convention).
No — fenced and inline code are removed before scoring.
No — scoring runs locally in your browser.
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