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Oanor Readability API
What it 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 response includes the scores, underlying text counts, an averaged grade level, estimated reading time, and a plain-English reading-ease interpretation. A separate endpoint counts syllables for a word or every word in a phrase. The listed endpoints are GET /v1/analyze, GET /v1/syllables, and GET /v1/meta. Request examples are available for curl, JavaScript, PHP, and Python; clients authenticate with an x-oanor-key header. The product page says computation is local, with no network calls, and describes results as fast and deterministic. It is aimed at content and copywriting tools, SEO and editorial workflows, education, accessibility checks, and UX-writing review. A browser playground offers 10 free test calls per day. The Free plan costs nothing and includes 2,340 calls per month at 2 requests per second. Paid monthly plans start at €6.80 a month. Plans use hard caps: requests above quota return HTTP 429 with no overage charge, and monthly plans can be cancelled anytime.
For and against
For
- Returns six readability scores and an averaged grade level.
- Includes estimated reading time and a plain-English interpretation.
- Separate endpoint counts syllables in words or phrases.
- Request examples cover curl, JavaScript, PHP, and Python.
- Browser playground offers 10 free test calls per day.
Against
- Requests above plan quota return HTTP 429.
- The Free plan allows 2 requests per second.
- Paid plans are billed monthly.
The verdict
Oanor Readability API returns multiple readability measures and related text statistics through listed endpoints. Check the plan quotas and rate limits against the expected request volume before integrating it.
Who it suits
Oanor Readability API suits developers building content, editorial, education, accessibility, or UX-writing workflows that need readability scores or syllable counts. It may also fit teams seeking monthly call quotas with hard caps.
Plans and prices
Free
2,340 calls/month · 2 requests/second · hard cap (429 above quota, no overage) · 6 formulas + counts
Read 8 Oct 2026 · oanor.com
Starter
46,500 calls/month · 8 requests/second · hard cap (429 above quota, no overage) · reading time + syllables
Read 8 Oct 2026 · oanor.com
Pro
238,000 calls/month · 20 requests/second · hard cap (429 above quota, no overage) · editorial & SEO pipelines
Read 8 Oct 2026 · oanor.com
Mega
875,000 calls/month · 50 requests/second · hard cap (429 above quota, no overage) · content-platform scale
Read 8 Oct 2026 · oanor.com
On the record
- Endpoints
- The page lists GET /v1/analyze, GET /v1/syllables and GET /v1/meta.oanor.com · read 8 Oct 2026
- Integration
- The page provides curl, JavaScript, PHP and Python request examples; clients authenticate with an x-oanor-key header.oanor.com · read 8 Oct 2026
- Maker
- The imprint identifies oanor.com as a service of Baduno GmbH, located in Frankfurt am Main, Germany.oanor.com · read 8 Oct 2026
- Processing
- The product page says computation is local, with no network calls, and describes results as fast and deterministic.oanor.com · read 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.oanor.com · read 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.oanor.com · read 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.oanor.com · read 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.oanor.com · read 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.oanor.com · read 8 Oct 2026
- Syllable endpoint
- A second endpoint counts syllables for a word or for every word in a phrase.oanor.com · read 8 Oct 2026
- Test access
- The browser playground offers 10 free test calls per day.oanor.com · read 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.oanor.com · read 8 Oct 2026
