Oanor Readability API
Oanor Readability API scores text using six formulas: Flesch Reading Ease, Flesch-Kincaid Grade, Gunning Fog, SMOG, Coleman-Liau, and Automated Readability I…
What Oanor Readability API is
Oanor Readability API scores text using six formulas: Flesch Reading Ease, Flesch-Kincaid Grade, Gunning Fog, SMOG, Coleman-Liau, and Automated Readability Index. Its analysis returns the six scores, text counts, an averaged grade level, estimated reading time, and a plain-English reading-ease interpretation. A separate endpoint counts syllables in a word or across a phrase. The listed endpoints are GET /v1/analyze, GET /v1/syllables, and GET /v1/meta; request examples are provided for curl, JavaScript, PHP, and Python, using an x-oanor-key header. The product page describes computation as local and says there are no network calls. A browser playground offers 10 free test calls per day. The API is aimed at content and copywriting tools, SEO and editorial workflows, education, accessibility checks, and UX-writing review. Plans use monthly quotas with hard caps: requests beyond quota return HTTP 429, with no overage charge. The free plan includes 2,340 calls per month at 2 requests per second.
Good
- Six readability formulas
- Returns grade level and estimated reading time
- Separate endpoint counts syllables
- Free plan includes 2,340 calls per month
Watch out
- Free quota is capped at 2,340 calls monthly
- Requests above quota return HTTP 429
- No overage option is listed
Who it suits
This API may suit developers building content, SEO, editorial, education, accessibility, or UX-writing workflows that need readability scores or syllable counts. The listed client examples cover several programming languages.
Verdict
Oanor Readability API provides readability metrics and syllable counts through a small set of endpoints. Check the monthly quota and hard-cap behavior against your expected request volume.
Plans and prices
From Oanor Readability API's own pricing page, checked 8 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free | Free | 2,340 calls/month · 2 requests/second · hard cap (429 above quota, no overage) · 6 formulas + counts · no credit card · Free |
| Starter | €6.80 a month | 46,500 calls/month · 8 requests/second · hard cap (429 above quota, no overage) · reading time + syllables · email support · €6.80 /month |
| Pro | €21.50 a month | 238,000 calls/month · 20 requests/second · hard cap (429 above quota, no overage) · editorial & SEO pipelines · priority support · €21.50 /month |
| Mega | €56.80 a month | 875,000 calls/month · 50 requests/second · hard cap (429 above quota, no overage) · content-platform scale · dedicated SLA · €56.80 /month |
The facts
Each one read from Oanor Readability API's own pages, with the date it was checked.
What it does
- Endpoints
- The page lists GET /v1/analyze, GET /v1/syllables and GET /v1/meta.checked 8 Oct 2026
- Integration
- The page provides curl, JavaScript, PHP and Python request examples; clients authenticate with an x-oanor-key header.checked 8 Oct 2026
- Processing
- The product page says computation is local, with no network calls, and describes results as fast and deterministic.checked 8 Oct 2026
- Purpose
- The API scores text with six readability formulas: Flesch Reading Ease, Flesch-Kincaid Grade, Gunning Fog, SMOG, Coleman-Liau and Automated Readability Index.checked 8 Oct 2026
- Quota behavior
- Plans use hard caps that return HTTP 429 above quota, with no overage charge; the page says plans are billed monthly and can be canceled anytime.checked 8 Oct 2026
- Returned data
- Analysis returns the six scores, underlying text counts, an averaged grade level, estimated reading time and a plain-English reading-ease interpretation.checked 8 Oct 2026
- Security and privacy
- The product FAQ says requests pass through an EU-based gateway, the upstream API key stays on the server, and no personal data is shared with the upstream provider beyond the request sent.checked 8 Oct 2026
- Support
- The page offers private one-to-one support tickets, and plan descriptions include email support for Starter, priority support for Pro and a dedicated SLA for Mega.checked 8 Oct 2026
- Syllable endpoint
- A second endpoint counts syllables for a word or for every word in a phrase.checked 8 Oct 2026
- Test access
- The browser playground offers 10 free test calls per day.checked 8 Oct 2026
- Use cases
- The API is described for content and copywriting tools, SEO and editorial workflows, education, accessibility checks and UX-writing review.checked 8 Oct 2026
The company
- Maker
- The imprint identifies oanor.com as a service of Baduno GmbH, located in Frankfurt am Main, Germany.checked 8 Oct 2026
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