Free ZoomInfo alternative: B2B company data from open sources

Every endpoint on this page was live-probed on 2026-07-29 by the Aidenix Atlas catalog.

What is a ZoomInfo alternative?

A ZoomInfo alternative is a data stack that returns the same account intelligence — company profile, hierarchy, buying signals — from 18,500,000+ official government records instead of a subscription database. In our data — the Aidenix Atlas catalog, where every source is live-probed — open sources covered 3 of ZoomInfo's 4 layers as of 2026-07-28, according to our probe logs: firmographics, corporate hierarchy, and financial events. The one layer with no open equivalent is employee contacts, and this page is explicit about that boundary. The 4 layers and where each one lives:

• Company profile and firmographics: state and national registries, filed by the companies themselves.
• Corporate hierarchy and ownership: beneficial-ownership registers and the global LEI graph.
• Financial events and funding: SEC filings, free and traceable to the source document.
• Contacts and org charts: the one layer open data does not replace.

Key facts at a glance

Which open sources replace each ZoomInfo layer?

An open replacement source is a government-run API that serves the same field group a vendor sells. In our data, 5 such sources cover the 4 layers above. According to our catalog probes on 2026-07-28, every endpoint below returned HTTP 200. None requires a paid license:

Three of the five speak plain JSON over GET with no key at all. Rate limits are generous by vendor standards: SEC asks for 10 requests per second with a declared user agent, Socrata portals allow anonymous access with soft throttling, and GLEIF imposes no published request cap.

Which source you start with follows from the question, not the vendor's feature list:

• If you only need to confirm a company exists and is active → one state registry or GLEIF query, no key, done in seconds.
• If you need ownership or group structure → GLEIF relationships plus Companies House PSC; skip the US state layer entirely.
• If you need buying signals → go straight to SEC filings; registries tell you who exists, filings tell you who moved.

Field-by-field: what each open source actually returns

Coverage is a per-field question, not a per-source one — a source that answers 3 of your 12 fields is useless for the other 9. This matrix is the field-level truth from our probe run of 2026-07-28, across the 5 sources above. «Partial» means available for a subset of entities, with the subset named:

Read the bottom three rows as the honest summary of this whole page: 14 fields, and the 3 that ZoomInfo sells hardest are the 3 no open source has.

How do you build an account profile without a subscription?

An account profile is a join across 2-3 registries keyed on company name, then registry number — the same pattern our company-360 chain runs across 38 open sources. The minimal manual version is 3 HTTP requests:

• Resolve the name: SEC full-text search for US filers or a state registry query — both return the canonical identifier (CIK or entity ID).
• Fetch the profile: data.sec.gov/submissions/CIK{cik}.json — status, industry code, address, tickers, filing history.
• Follow the hierarchy edge: the GLEIF LEI record links subsidiaries to parents across borders through one open identifier.

# names collide globally — filter by country or resolve a registry ID first
curl "https://api.gleif.org/api/v1/lei-records?filter%5Bentity.legalName%5D=Stripe"

Here is what that exact query returned when we ran it on 2026-07-28 — a live sample, not a mock:

Note what the sample teaches: the top hit is a Belgian company named STRIPE, followed by Irish special-purpose entities — not the San Francisco parent. That is the entity-resolution lesson every vendor database hides from you: name search returns namesakes, and the fix is to filter by jurisdiction or resolve through a registry number first. Vendors solve this silently; with open data you solve it consciously, and you can audit the answer.

What does a real registry response look like?

A registry response is raw truth with sharp edges, and seeing one before you build saves a sprint of surprises. We queried the New York Department of State corporation registry for «APPLE» on 2026-07-28; the first two of 300+ matches:

Neither is the Apple you meant — and that is the point. According to our probe logs, name collision is the single most common failure when teams replace a vendor with registries: ZoomInfo pre-disambiguates behind the scenes, registries return every legal entity that matches. The working pattern in our data: search the registry, rank candidates by county or address against what you already know, then confirm through a second source — an SEC CIK, an LEI, or a filing signature. Two sources agreeing is the open-data equivalent of a vendor's «confidence score», except you can see why.

What can't open data replace?

The contact layer is the boundary: across all 18,500,000+ records in the 5 sources above, none publishes a work email or a direct dial. Registries name directors and beneficial owners — for a typical private company that is 2-4 people, according to our catalog's officer-record structure — but the org chart below officer level comes from licensed feeds with their own consent chains. In our data, the honest split is:

• Moves to open sources at zero license cost: firmographics, hierarchy, filings, funding events.
• Stays paid: person-level contact discovery, org charts, intent scores.
• Structural lag: registries update on filing schedules — an acquisition appears when the paperwork lands, not when the press release does.
• No open equivalent at all: «likelihood to buy» scoring — that is a model output, not a record.

Treat open data as the verified skeleton and commercial layers as optional flesh, not the other way around.

Frequently asked questions

Is there a truly free ZoomInfo alternative with contact data? No. A free source of employee emails and direct dials does not exist, because no government registry collects that data and no legitimate open project can redistribute it. Anything marketed as one is reselling scraped data with an unresolved consent problem.

How fresh are open registry records? As fresh as the filing. In our probes, SEC submissions appear within a day of filing, state registries update on their own schedules — daily to weekly — and GLEIF refreshes LEI records daily. The delay you actually feel is corporate: companies file on legal deadlines, not news cycles.

Can I use these sources commercially? Yes — US federal data (SEC) is public domain, state registry terms generally permit reuse, and GLEIF publishes under CC0. Companies House requires attribution under the UK Open Government Licence. Verify the specific portal's terms before redistributing bulk copies.

How we verify these claims

Every endpoint on this page sits in the Aidenix Atlas catalog — a map of nearly 4,000 real data sources — and was live-probed on 2026-07-28: we sent real requests, recorded HTTP status and response shape, and the record counts above come from those responses, not from vendor marketing. The sample tables are unedited API output from the same probe run. When a source dies or changes schema, the probe fleet catches it and this page gets re-verified — the «last probed» date above is the freshness contract.

Source facts from the Aidenix Atlas catalog, probed 2026-07-28. Found an error? The catalog re-probes on every report.