Free tools API

The free tools on rankparse.com (backlink checker, domain authority checker, tech stack detector and others) are served by a small set of /v1/tools/* endpoints. They cost no credits and need no API key, but they return trimmed results and are rate limited per IP address.

Tools

All tools are GET requests on https://api.rankparse.com/v1/tools/<tool>.

Input rules:

• domain, domain_a, domain_b: a bare domain such as stripe.com (letters, digits, dots, hyphens; at least one dot).
• url: an http(s) URL. A bare host such as hubspot.com/pricing is accepted and promoted to https://.
• link-intersect is order-sensitive: domain_a is the competitor and domain_b is your domain, the same convention as the paid endpoint.

Example

curl "https://api.rankparse.com/v1/tools/domain-age?domain=github.com" \
  -H "cf-turnstile-response: <token from the Turnstile widget>"

{
  "domain": "github.com",
  "registered_at": "2007-10-09",
  "registrar": "MarkMonitor Inc.",
  "popularity_rank": 38,
  "tool": "domain-age",
  "tier": "anonymous",
  "quota": { "limit": 5, "remaining": 4, "reset_at": 1760259200000 }
}

Response shapes

Every response carries three extra fields added by the platform: tool (the tool name), tier and quota. The rest of the body depends on the tool:

Limits and rate limiting

• The limit is per tool: five domain-age calls do not use up your backlinks allowance.
• Every request uses a slot, including repeat requests that are answered from cache and requests that end in an error.
• The quota object on each response shows limit, remaining and reset_at (a millisecond Unix timestamp for when the oldest counted request ages out).
• Successful results are cached for 24 hours and shared between visitors, so a popular domain may return a result computed earlier.
• Free tools return fixed, smaller result sets (see the table above) and no pagination, filtering or sorting parameters.
• The free page-speed tool has its own daily budget, separate from the paid page-performance caps.

Errors

Errors use the same shape as the rest of the API: error, code and usually message.

{
  "error": "Too Many Requests",
  "code": "quota_exceeded",
  "message": "Free limit reached. Sign up for 25/day at https://rankparse.com/signup",
  "reset_at": 1760259200000,
  "signup_url": "https://rankparse.com/signup",
  "tool": "domain-age",
  "tier": "anonymous",
  "quota": { "limit": 5, "remaining": 0, "reset_at": 1760259200000 }
}

Empty results are not errors: a domain with no data returns 200 with empty arrays.

Emailed backlink report

POST /v1/tools/backlink-report powers the "email me a backlink report" form. It takes a JSON body with domain and email, generates a PDF with the domain's authority, top backlinks and top referring domains, and emails a download link. It also requires the Turnstile token.

• One free report per email address per day, and 3 per IP address per day (email_quota_exceeded and ip_quota_exceeded, both 429).
• Other errors: invalid_body, invalid_domain, invalid_email (all 400), turnstile_failed (403), report_failed (500).
• The download link, GET /v1/tools/report/:id, returns the PDF and works for 24 hours, then answers 404.

Because the link is delivered by email to the address you supply, this endpoint is not a data API. To pull backlink data into your own tools, use Backlinks.

When to use the paid API