1Lookup is a self-serve data verification and enrichment platform for SMBs, exposing more than forty products through a single REST API and one universal credit balance. It validates phone numbers (line type, carrier, HLR reachability, number portability, DNC status, spam/scam reputation, fraud score), email addresses (syntax, MX, deliverability, disposable and role-based detection) and IP addresses (geolocation, VPN/proxy/Tor and datacenter detection), then extends into B2B company and contact data (firmographics, prospect and account search, contact append, skip trace), SEO and web intelligence (domain authority, backlinks, keyword metrics, audience reports, SERP and website scraping), social and media lookups, property data and audio transcription. The same engine powers a web dashboard with batch CSV validation, roughly twenty-five free rate-limited browser tools, and a first-party hosted MCP connector authorized with OAuth 2.1 that gives AI agents five of the core tools without an API key.
1Lookup publishes 3 APIs on the APIs.io network. Tagged areas include Phone Validation, Email Verification, IP Intelligence, Fraud and Risk, and Data Enrichment.
The 1Lookup catalog on APIs.io includes 1 event-driven AsyncAPI specification.
1Lookup’s developer surface includes documentation, API reference, getting-started guide, engineering blog, support, pricing, signup flow, and 34 more developer resources.
Regulatory Posture applies to this provider. Its tags matched the
Horizontal (data, software, accessibility, platform) regime, so
Regulatory Posture carries 15 points of the composite.
If this regime is wrong for your business, say so on your
provider repo — the
applicability map is public and we will correct it.
Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for
this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero:
never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and
several others — scorable at all.
The six quality facets above are damped to 85 points between them,
because the conditional facet above carries the other
15. That is why each facet's contribution is shown against a damped
maximum: raising a quality facet moves the composite by 85% of its nominal
weight, not 100%. The full arithmetic is at apis.io/rating/.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/1lookup: open an issue to ask a question, or submit a pull request to add artifacts.
Submit an artifact on GitHub — free →Manage your own listing — the Influence plan, $499/mo →
Machine-readable content indexes (llms.txt and llms-full.txt) for AI and answer engines, indexing the free tools, every product page, the comparison pages and the key site secti...
1Lookup ships a first-party hosted (remote) MCP connector at https://app.1lookup.io/api/mcp. It is a URL-only integration — no SDK, no pasted API key — authorized with OAuth 2.1...
Discovery needs no key. Ratings and market analysis are Pro.
Get an API key
Free tier, no form to fill in. Signing in shares your email address with us — we
store it to create your key and to recognise you if you sign in with another
provider. See our Privacy Policy and
Terms.
Kin Score
How this is scored →