10 Best B2B Data Providers for 2026

Full disclosure: Clay is our product, so we put it first. It also holds the highest rating on this list (4.9/5), and running multiple data providers in one place is the most common thing teams build on Clay. Here's what it does well and where it doesn't fit.

Clay is not a data provider in the usual sense. It's the layer that sits on top of the providers, so instead of choosing between ZoomInfo, Cognism, or a developer API and living with that source's blind spots, you run 200+ of them in a single waterfall. Clay checks each provider in the order you set, stops at the first verified hit, and only charges for the record that comes back. On top of the raw data it adds Signals (job changes, funding, hiring, web intent) and Claygent, an AI research agent that answers questions no provider sells as a field, like whether an account runs a specific tool or mentions SOC 2 in a job post. The finished record syncs to Salesforce or HubSpot and re-runs as the underlying sources change.

Apollo owns a large B2B contact database, over 200 million contacts by its own count, and bolts prospecting and sending on top. As a data provider it's the accessible default: the free tier lets a founder or small team pull contacts and start outbound without a procurement cycle, which is why so many companies meet their first data source here.

The trade-off is depth and consistency. Apollo's data leans heavily toward North America and gets thinner internationally, and because it's a self-serve database rather than a heavily human-verified one, accuracy varies record to record. Treat it as a broad, cheap source you verify, not the last word on a hard-to-find contact.

ZoomInfo is the source most other providers are measured against. Its database spans roughly 14 million companies and 235 million business professionals, layered with intent data, org charts, and WebSights website-visitor identification. For an enterprise team selling into North America, it's the closest thing to a data provider of record: if a contact exists in the US market, ZoomInfo probably has it.

That authority comes at enterprise cost and with regional limits. Pricing is quote-based on annual contracts, the entry point is steep, and coverage that's excellent in the US thins noticeably across parts of EMEA and APAC. It's a deep source to anchor on, but a heavy commitment to make it your only one.

Seamless.AI is a different kind of source: instead of serving records from a fixed database, it works like a search engine that compiles contact data in real time when you look someone up. It finds emails and phone numbers, runs as a Chrome extension, and offers buyer-intent add-ons, which suits high-volume prospecting teams that would rather generate a fresh contact than trust a stored one.

Real-time sourcing is both the appeal and the risk. Because the data is assembled on the fly, accuracy swings from record to record, and the credit-and-upsell model means costs can climb as you scale. It's a strong source to run alongside a verified database, not on its own.

Cognism is the provider to reach for when Europe is your market. Its Diamond Data phone numbers are human-verified, its UK, EMEA, and DACH coverage is deep, and its GDPR-first sourcing is a real differentiator for teams that can't take chances on how data was collected. As a source it does what US-first databases can't: put a compliant, connectable European number in front of a rep.

Where the US incumbents thin out abroad, Cognism thins out at home. Coverage is strongest in Europe and lighter than ZoomInfo across North America, and it's a premium, quote-based product with no public tiers. It's the European anchor in a provider mix, not a global one-stop source.

Lusha is the most approachable provider on the list. Its Chrome extension pulls a work email and phone number straight off a professional profile, it handles bulk enrichment, and it syncs to your CRM. For an individual rep or a small team, it's a source you can start using in minutes, no contract, no onboarding.

That accessibility caps its depth. The underlying dataset is lighter than the enterprise houses, credit limits arrive quickly on lower tiers, and coverage is best on straightforward contacts. It's a great convenience source for one-off lookups, less so for sourcing an entire market.

LeadIQ is a data source built around the prospecting workflow. Its strength isn't a headline database size, it's how cleanly it moves a contact from a LinkedIn profile into your CRM and sequencer, deduped and formatted, with job-change tracking so a saved contact tells you when it's time to reach out again. For SDR teams that live in the outbound tooling, it removes the copy-paste tax between finding a contact and working it.

The data itself is solid rather than exceptional. Reviewers flag occasional wrong emails and inconsistent quality on harder contacts, and phone coverage lags the phone-first providers. It's a workflow-friendly source best paired with a deeper database for the contacts it can't complete.

Clearbit, now HubSpot Breeze Intelligence, is a data source that lives inside HubSpot. It fills firmographic and technographic fields on the record, shortens forms by enriching a visitor from just an email, and de-anonymizes website traffic to reveal in-market companies. If your stack lives in HubSpot, this is the source that requires no integration, the data simply lands on the record.

The value is bound to that ecosystem. It's most useful inside HubSpot, runs on credit packs on top of a paid subscription, and the standalone Clearbit API that developers once built on has been retired. Some users also report accuracy slipping on older records. As a source it's convenient for HubSpot shops and limited for everyone else.

D&B Hoovers draws on Dun & Bradstreet's decades-old commercial database and the DUNS numbering system, which makes it the firmographic source of record for a lot of enterprises. Its strength is company data: corporate family trees, financials, industry codes, and firmographics that hold up in procurement, credit, and account-planning use cases where provenance matters more than volume.

For sales prospecting specifically, it's a heavier fit. Contact-level data draws more complaints than the company data does, the interface feels dated, and contracts are quote-based with built-in annual increases and add-on fees that reviewers find hard to predict. It's a firmographic authority to pair with a contact-first provider, not a modern prospecting engine.

People Data Labs is a provider aimed at builders rather than reps. It sells raw access to a large person and company dataset through an API and flat data files, so a data or engineering team can enrich records, power a product feature, or feed a model without a sales-facing UI in the way. Reviewers consistently praise the data quality, the documentation, and the flexible Elasticsearch-style querying.

That developer focus is also the limit. There's no app, CRM sync, or workflow layer, so a non-technical GTM team has nothing to click. Its G2 footprint is small next to the sales-tool incumbents, and getting value out of it assumes someone can write against the API. It's an excellent source component, not an off-the-shelf prospecting tool.