📝Readability Score
Compute readability metrics for a block of text: Flesch Reading Ease score, Flesch-Kincaid grade level, and word/sentence/syllable statistics. Deterministic formulas — useful for checking documentation, prompts and agent output clarity.
Worked examples
Simple text
GET /api/v1/dev/readability?text=The%20cat%20sat%20on%20the%20mat.%20It%20was%20warm.%20The%20dog%20ran%20fast.
Result: 117.8 — Very easy (5th grade)
Complex text
GET /api/v1/dev/readability?text=Notwithstanding%20the%20aforementioned%20considerations%2C%20the%20implementation%20necessitates%20comprehensive%20evaluation%20of%20multifaceted%20jurisdictional%20requirements.
Result: -112.2 — Very difficult (graduate)
Machine API (x402)
$0.002 / callThis tool is also a JSON API for AI agents. Requests without payment receive 402 Payment Required plus instructions; agents pay USDC on Base via the x402 protocol — no accounts, no API keys.
GET /api/v1/dev/readability?text=The%20cat%20sat%20on%20the%20mat.%20It%20was%20warm.%20The%20dog%20ran%20fast. HTTP/1.1
Host: localhost:3000
→ 402 (payment required, instructions in headers)
→ 200 (after X-PAYMENT header; JSON body below)
{
"tool": "dev/readability",
"input": {"text":"The cat sat on the mat. It was warm. The dog ran fast."},
"result": { "value": 117.8, "answer": "117.8 — Very easy (5th grade)" }
}Agent docs: /llms.txt · OpenAPI spec · integration guide
About this tool
Score any text with the Flesch Reading Ease formula (206.835 − 1.015×words/sentence − 84.6×syllables/word) and get the Flesch-Kincaid grade level — the standard metrics for checking that documentation, prompts and agent output match your audience.
Frequently asked questions
What score should I aim for?
For general audiences, aim for 60–80 (plain English, 8–9th grade). Technical documentation typically lands at 30–50. Agent-generated user-facing text should be checked against this.