{"uid":"cap_R3KF1-cErb4S9iWxhy53M","slug":"24k-labs-readability-score-api-0e0f0df3","name":"24K Labs Readability Score API","description":"Word/sentence/syllable counts, reading time, plus Flesch Reading Ease, Flesch-Kincaid, Gunning Fog, SMOG, ARI, and Coleman-Liau grade levels in one call.","url":"https://api.24klabs.ai/api/readability-score","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"text":{"type":"string"}}},"responseSchema":{"type":"json","example":{"words":17,"flesch_reading_ease":90}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_wxYCDq6e_diB4cuWi0ZTo","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Analyzes text and returns word/sentence/syllable counts, reading time, and multiple readability grade-level scores (Flesch, Flesch-Kincaid, Gunning Fog, SMOG, ARI, Coleman-Liau) in a single call.","exampleAgentPrompt":"Can you check the readability of this article draft and give me the Flesch Reading Ease score, Gunning Fog index, and estimated reading time? Here's the text: [paste text]","exampleUseCases":[{"title":"Blog post complexity check","prompt":"I just wrote this blog post intro — can you run a readability analysis on it and tell me the Flesch Reading Ease score and estimated reading time? I want to make sure it's accessible to a general audience."},{"title":"Legal document grade-level audit","prompt":"This is a terms-of-service document. Can you compute all the readability grade levels for it — Flesch-Kincaid, SMOG, Coleman-Liau, and the rest — so I know roughly what education level a reader needs to understand it?"},{"title":"Healthcare content simplification","prompt":"I need to check if this patient instructions text is written at an appropriate reading level. Can you get the SMOG score and ARI for it, along with word and sentence counts?"}],"resultDescription":"Returns a JSON object containing word count, sentence count, syllable count, estimated reading time, Flesch Reading Ease score, Flesch-Kincaid grade level, Gunning Fog index, SMOG index, ARI (Automated Readability Index), and Coleman-Liau index — all computed in a single API call from the submitted text.","failureModes":["Empty or missing text body returns an error","Extremely short text (single word) may yield unreliable or undefined grade-level scores","Very large text payloads may exceed request size limits","Non-English text may produce inaccurate syllable counts and readability scores since formulas are calibrated for English"],"whenToPreferThis":"Choose this endpoint when you need multiple standard readability metrics computed simultaneously in one call rather than calling separate services. Ideal for content pipelines, writing assistants, educational tools, compliance checks, or any workflow that needs to assess text complexity at scale with a predictable per-call cost of $0.002 USDC.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:53:48.231Z","isFirstParty":false}