The top 5 sex offender APIs in 2026

1. Offendersearch — best overall

Our product, so judge the numbers, not the assertion. One call searches 58 US registries — 1.5 million records in one schema, the largest corpus on this list by a wide margin — and the response reports which sources answered, so an incomplete search can never be mistaken for a clean one. Every match carries a confidence score, the basis it matched on, and a citation to the official registry record with a last-checked timestamp:

{
  "status": "complete",
  "counts": { "records": 1, "sourcesQueried": 58,
              "sourcesComplete": 58, "sourcesIncomplete": 0 },
  "records": [{
    "matchConfidence": 1.0,
    "matchBasis": ["lastName", "firstName", "dob"],
    "matchState": "dob_match",
    "name": { "full": "John A. Doe" },
    "sources": [
      { "jurisdiction": "NJ", "registryName": "State Sex Offender Registry",
        "recordUrl": "https://…", "lastCheckedAt": "2026-08-30T09:14:00Z" }
    ]
  }]
}

The pricing is the simplest on the list and the lowest at volume among the pay-as-you-go APIs: a flat $0.15 per call, $0.11 past 2,000 a month, with GIS radius search, match scoring and photographs included rather than sold as surcharges or separate monthly plans. Sign-up is self-serve with no card and no sales call, there is a no-code dashboard for non-developers, and an MCP server lets AI agents run the same searches on the same key. Built for US public-records screening by design; for FCRA consumer reports, pair it with a CRA workflow.

• Largest published corpus on the list: 1.5M records across 58 registries
• Lowest at-volume price of the pay-as-you-go APIs: $0.11/call past 2,000 a month, everything included
• The only API here that reports per-source completeness on every response

2. offenders.io — the runner-up

The other serious developer API in this space, and the one to get a second quote from — our field-by-field comparison is public. Its site advertises 900,000+ offender records across 184 jurisdictions, with a well-documented response schema. Read the pricing page closely, because the ladder matters at volume: $0.20 per call for the first 2,000 requests, then $0.15, with live registry lookups an extra $0.05 per call, fuzzy matching an extra $0.02, and GIS radius search sold separately as monthly plans from $99 (2,000 searches) to $3,499 (100,000). The ladder looks harmless on a demo account; at volume it compounds. And its updatedAt field records when a row last changed — which is not the same claim as when it was last verified. Different question entirely.

• Strongest fit: teams comparing per-call registry APIs
• Drawback: a 900K+ advertised corpus against 1.5M here — 600,000 records is a lot of missing answers
• Drawback: the features included in our flat price are surcharges and separate plans on theirs

3. Family Watchdog — prepaid batch checks

The best-known consumer registry brand, with a genuine JSON/XML API sold as prepaid packages: $75 for 500 calls down to $1,000 for 10,000, email sales above that, and no free tier published. The schema is dated — every offense collapses into four conviction-type buckets — but its per-state statistics page is quietly one of the most useful pages in the industry: it shows, on one screen, how differently states disclose (Texas listing over 100,000 registrants while some states publish under 2,000). Check any vendor’s “nationwide” claim against that distribution.

• Strongest fit: prepaid CSV batch checks under a familiar brand
• Drawback: four offense buckets and no free tier; integration feels its age

4. Checkr — registry check inside employment screening

Checkr sells FCRA employment screening, not registry lookups — the registry search is a component inside packages that start at $29.99 per report, run on consented candidates. Here is the detail its own API reference shows and no listicle mentions: the documented sex-offender record contains exactly seven fields — registry, full name, age, DOB, registration start, registration end, state. Count them. No offense description. No address. No photograph. It is built to output a screening result, not registry detail — the right tool when you are hiring, and the wrong shape when you need the record.

• Strongest fit: employment and gig screening where FCRA applies
• Drawback: seven-field records at $29.99+ per report — an adjudication signal, not a data product

5. NSOPW — the free official website

The Department of Justice’s portal is where every comparison should start, because it is free and official — and its own FAQ states the boundary plainly: the browser is the only way to search it. There is no API. Radius search is capped at 1, 2 or 3 miles, and only works where a state supplies coordinates — the site’s own disclaimer tells you when one does not. Run the same address at a 25-mile radius on any API above and you will see the difference immediately. For occasional manual lookups, use it and pay no one; here is the honest line where that stops working.

• Strongest fit: occasional manual one-person lookups
• Drawback: browser-only by its own FAQ, 3-mile radius cap, no structured output

Integrating a sex offender search API in an afternoon

The integration test we would apply to any vendor on this list: from signup to first real record, how many steps, and does any step involve a human on their side? Here is the entire path on ours — no card, no sales call, no sandbox-to-production migration, because the free tier runs on production data:

curl https://api.offendersearch.app/v1/search \
  -H "X-API-Key: $KEY" \
  -H "Content-Type: application/json" \
  -d '{ "query": { "firstName": "John", "lastName": "Doe",
                   "dob": "1980-04-12" } }'

Three fields deserve attention in any vendor’s response before you commit. counts.sourcesIncomplete — or its absence — decides whether an empty result can be trusted. matchBasis tells your reviewers why a record matched, which is the difference between a queue your team clears in minutes and one it argues about. And the per-source recordUrl plus lastCheckedAt is what lets a decision survive an audit. If a response lacks all three, you are buying a list of names.

Sources and method

How this article was made, since you should ask that of any comparison: a research sweep on September 2, 2026 read each vendor’s own pricing page and API reference — software-assisted for the sweep, with every fact checked against the linked page by a person before publishing, and the response examples taken from our own production API. No third-party blogs were used as sources. We re-verify these numbers monthly; if you catch one that has drifted, email support@offendersearch.app and we will correct it and credit the catch.

• offenders.io — pricing
• offenders.io — API docs
• Family Watchdog — API page
• Family Watchdog — per-state statistics
• Checkr — pricing
• Checkr — API reference (sex offender search object)
• NSOPW — FAQ (browser-only access, radius limits)
• NSOPW — registry directory

Beyond one-off lookups: monitoring & alerts

Every API in the table above answers the question the moment you ask it. The capability that sets the best option apart is what happens next: a registry record can appear, change or be removed the day after a clean check, and a one-off lookup never tells you. Offendersearch turns a search into a standing watch — set one on a person by name and date of birth, or on an address and radius, and we email you the moment a matching registry record is added, changes, or is removed, checked every morning against our continuously updated data.

Manage watches in the dashboard Notifications section or over the API with POST /v1/monitors — the same key as search. Full details are in monitoring & alerts and the monitoring API reference.

Monitoring is for personal awareness and safety. It is not a consumer report and must not be used for FCRA-governed hiring, tenancy, or credit decisions.