Explorium vs Captain Data vs Hunter.io

Objective, side-by-side analysis of Explorium, Captain Data, and Hunter.io to help you evaluate features, pricing, and performance and find the perfect fit for your data needs.

Explorium

4.8

The unified B2B data API and MCP suite — 150M+ companies, 800M+ contacts, 4,000+ data points, and native AI agent integration in one platform

  • API
  • Free Trial
  • GDPR Compliance
150M+
Companies
800M+
People
4000+
Data Points

Selected Customers

Clay • Common Room • Cognism • Outreach • Bombora • Monday.com • Artisan

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Captain Data

4.7

The production-ready B2B data extraction API — 500M+ profiles, LinkedIn-native search, and a no-code automation builder for sales teams and developers

  • API
  • Free Trial
  • GDPR Compliance
50M+
Companies
500M+
People

Selected Customers

Rippling • lemlist • AiSDR • ZELIQ

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Hunter.io

4.4

The original email finder and verifier — simple, accurate, and trusted by over 6 million professionals

  • API
  • Free Trial
  • GDPR Compliance
76M+
Companies

Selected Customers

Google • IBM • Microsoft

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Primary Use Cases

Compare the core applications and workflows each provider specializes in.

Explorium

  • GTM Agents

    Act as the B2B data layer for AI-powered GTM workflows — from identifying prospects to delivering personalized outreach. Supports MCP-native access via Claude and other AI agents.

  • ABM Targeting

    Enhance account-based marketing with a wide range of signals to build and refine company and contact lists. Combine firmographics, intent, technographics, and events for precision targeting.

  • AI Recruiting

    Build recruiting automation systems on top of a premium B2B data layer. Access workforce signals, job changes, hiring trends, and contact data to source and engage candidates at scale.

Signals powering these use cases

  • Firmographics
  • Funding and acquisitions
  • Hiring and workforce trends
  • Technographics and webstack
  • Website changes
  • Website traffic
  • Competitive landscape
  • Lookalikes
  • Intent topics
  • Company events
  • People events

Captain Data

  • Sales Prospecting via API

    Search 500M+ professional profiles and 50M+ companies using LinkedIn Sales Navigator-compatible queries — delivered via a REST API with sub-500ms response time and 99% uptime SLA.

  • CRM & List Enrichment

    Enrich existing CRM records or prospect lists with verified emails, firmographics, tech stack, hiring trends, and funding data at scale — reducing SDR research time from 30 minutes to 2 minutes per prospect.

  • Product-Embedded Data

    Embed B2B data enrichment directly into SaaS products via a single REST integration — live in hours, not weeks. Trusted by Rippling, lemlist, and AiSDR for high-volume data pipelines.

Signals powering these use cases

  • LinkedIn Sales Navigator-compatible people search
  • Company search and enrichment
  • Verified email addresses
  • Technographic data (tech stack)
  • Hiring trends
  • Funding data
  • 90%+ coverage rate

Hunter.io

  • Email Discovery

    Find professional email addresses for any domain or individual using Hunter's indexed database of 76M+ websites and public sources.

  • Email Verification

    Verify email deliverability before sending with multi-step checks including SMTP validation and confidence scoring to reduce bounce rates.

  • Cold Email Campaigns

    Send personalized cold email sequences directly from Hunter with built-in scheduling, follow-ups, and tracking for opens, clicks, and replies.

Signals powering these use cases

  • Domain-level email pattern detection
  • Public web indexing of 76M+ websites
  • Confidence scoring on every email found
  • Email verification with SMTP checks

Snapshot

Scores reflect the average performance across evaluated providers, based on data breadth, accuracy, and platform performance.

Explorium Snapshot

  • Company coverage 3.5
  • Signals depth 5.0
  • Freshness 1.8

Captain Data Snapshot

  • Company coverage 3.0
  • Signals depth 2.5
  • Freshness 3.0

Hunter.io Snapshot

  • Company coverage 4.7
  • Signals depth 1.5

Detailed Feature Comparison

Side-by-side analysis of Explorium, Captain Data, and Hunter.io across data coverage, platform capabilities, and technical specifications.

Feature Comparison
Explorium
Captain Data
Hunter.io
Data Enrichment
ML Discovery
API Access
REST JSON API with batch support (up to 100 entities), webhooks, sync/async; up to 100 QPS; 99.999% uptime
Full REST API; sub-500ms response time; 99% uptime SLA
Full RESTful API; no premium plan required to use API
SLA
Up to 99.999% uptime; rate limit 200 requests/min per key
99% uptime SLA
Near 100% uptime
Compliance
GDPR, SOC 2, CCPA, ISO 27001
GDPR, SOC 2 Type II
GDPR and CCPA compliant
Custom Entities
Real-time Lookups
Global Coverage
150M+ companies and 800M+ contacts across 150+ countries
50M+ companies and 500M+ contacts globally
Global with strongest coverage in US and Europe
CRM Integration
Available on custom enterprise plans
HubSpot via Make integration; API for others
Salesforce, HubSpot, Pipedrive, Zapier
Platform interface
REST JSON API, MCP server (AgentSource MCP), batch support up to 100 entities, webhooks, sync and async modes
REST API, no-code workflow builder, Make (no-code) integration
Web app, Chrome extension, API
Natural language search
Workflow automation
Automation integrations
n8n, Claude, custom webhook integrations
Make (Technology Partner), API, webhook support
Zapier (5,000+ endpoints)
Company coverage
150M+ company profiles
50M+ companies
76M+ websites indexed for email pattern detection
People coverage
800M+ people profiles (767M+ verified contacts)
500M+ professional profiles
Millions of professional email addresses across US and European markets
Geographic coverage
150+ countries
Global; strong US and EU coverage
Global, with strongest coverage in US and Europe
Data sources type
50+ data providers; proprietary ML enrichment; real-time web signals
Proprietary data extraction infrastructure; LinkedIn Sales Navigator-compatible
Publicly available web pages, company websites, press releases, social media profiles
Global schema consistency
Unified schema across 4,000+ data points globally; consistent API response structure
Consistent REST JSON API; unified schema across endpoints
Consistent email + confidence score schema across all records
Refresh frequency
Daily for high-velocity signals; weekly for semi-dynamic attributes; monthly/quarterly for stable firmographics
On-demand extraction; 90%+ coverage rate
Continuous web crawling; database updated regularly
Business enrichments
Company size, revenue, industry, tech stack, funding stage, headcount trends, competitive landscape, website traffic
Company size, industry, tech stack, funding data, hiring trends, LinkedIn URL
Domain-level email patterns, company email format detection
Prospect enrichments
Job title, seniority, verified email, phone, LinkedIn URL, job history, people events
Verified email, job title, seniority, LinkedIn profile, company affiliation
Individual email addresses, job titles, confidence scores
Enrichment categories
Firmographics, technographics, intent, funding, events, contact, website signals, lookalikes
People data, company data, emails, tech stack, hiring trends, funding
Email discovery, email verification
Intent data
Event signals
Company events (20+ types), people events (5+ types), funding rounds, acquisitions, hiring surges
Hiring trends, funding signals
-
Technographics
Hiring and growth signals
Matching precision
98% company accuracy; 95% people accuracy
90%+ coverage rate claimed
80–90% average email accuracy; confidence score assigned to each result
Confidence scoring
Validation methodology
Advanced ML-based deduplication; 98%+ company accuracy; 95% people accuracy
GDPR compliant, SOC 2 Type II certified
SMTP checks, domain validation, pattern matching, confidence scoring
Deduplication logic
Advanced ML-based deduplication across 50+ data providers
-
Deduplication via domain email pattern recognition
API availability
QPS performance
Up to 100 QPS; 200 requests/min per API key
Sub-500ms average response time; 99% uptime SLA
Near 100% uptime; fast RESTful API response times
CRM integrations
Custom plan — CRM integrations available
HubSpot (via Make integration confirmed)
Salesforce, HubSpot, Pipedrive
Data warehouse support
Custom plan — warehouse ingestion available
-
-
Bulk data delivery
Claude Connector
ChatGPT App
Custom MCP
Claude Plugin
ChatGPT Plugin
OpenClaw Plugin
Skills
16
-
-
GDPR compliance
CCPA support
SOC 2
-
ISO certifications
ISO 27001
-
-
SLA uptime
Up to 99.999% uptime SLA
99% uptime SLA
Near 100% uptime stated
Pricing model
Usage-based API credits with custom enterprise plans
Credit-based per record (no seat fees)
Credit-based subscription
Credit system
Credit-based; 100 credits on free trial; self-serve and custom plans scale with volume
1 credit per record collected or enriched; base rate €59.99/1K credits with volume discounts
Credits consumed per email search or verification; separate credit pools for searches vs. verifications
Tier structure
Free trial, Self-serve, Custom Enterprise
Free, Growth (~$399/mo), Scale (~$999/mo), Enterprise
Free, Starter ($49/mo), Growth ($69/mo annual), Enterprise (custom)
Free trial details
30-day free trial with 100 credits; covers API and MCP access
100 free credits on signup
Permanent free plan: 25 searches and 50 verifications per month
Budget commitment options
Custom enterprise plans with volume negotiation
Monthly or enterprise volume negotiation
Monthly or annual billing; annual provides ~30% savings
Custom plans available
Bulk deals support
Resell rights
-
-
-

Pricing

Compare pricing models, flexibility, and commitment structure.

Pricing Dimension
Explorium
Captain Data
Hunter.io
Pricing Model
Usage-based with custom enterprise plans
Credit-based per record, no seat fees
Credit-based subscription
Commitment Structure
One-time or custom; no mandatory annual lock-in on self-serve
Monthly; Enterprise custom
Monthly or annual commitment; annual saves ~30%
Payment Recurrence
One-time or custom
Monthly
Monthly or Annual
Free Trial
30-day free trial with 100 credits; no credit card required
100 free credits on signup; no credit card required
Free plan with 25 searches/month and 50 verifications/month — no time limit
Enterprise Customization
Yes — custom plans include CRM integrations, warehouse ingestion, resell rights, and dedicated support
Yes — custom pricing, dedicated support, SLA
Custom pricing for 20,000+ monthly searches
Onboarding Model
Self-serve for API and MCP; dedicated onboarding for enterprise custom plans
Self-serve API; Make Technology Partner for no-code; enterprise dedicated support
Self-serve; extensive documentation and help center available

What Experts Say

V

Verified Customer

Head of Growth, B2B SaaS

"Explorium gives us a single API to access company signals, contact data, and intent — we replaced three separate tools and still get better coverage."
Verified User for Explorium
V

Verified G2 Reviewer

Sales Operations, B2B SaaS

"Captain Data cut our SDR research time from 30 minutes to 2 minutes per account — the LinkedIn-compatible API just works with our existing workflows."
Verified User for Captain Data
V

Verified G2 Reviewer

Sales Development Representative, Mid-Market Company

"What I like best about Hunter is how simple and efficient it makes finding and verifying professional email addresses. The interface is clean and easy to use, and the domain search feature quickly provides relevant contacts along with confidence scores, which saves a significant amount of time. The email verification tool is also very reliable, helping reduce bounce rates and improve outreach performance."
Verified User for Hunter.io

Frequently Asked Questions

Is Captain Data better than Hunter.io?

It depends on your use case. Captain Data The production-ready B2B data extraction API — 500M+ profiles, LinkedIn-native search, and a no-code automation builder for sales teams and developers Hunter.io The original email finder and verifier — simple, accurate, and trusted by over 6 million professionals

What is the difference between Captain Data and Hunter.io?

See the feature-by-feature comparison above. In short: Captain Data focuses on The production-ready B2B data extraction API — 500M+ profiles, LinkedIn-native search, and a no-code automation builder for sales teams and developers while Hunter.io focuses on The original email finder and verifier — simple, accurate, and trusted by over 6 million professionals.

How much does Captain Data cost compared to Hunter.io?

Captain Data pricing model: Credit-based, no seat fees. Hunter.io pricing model: Credit-based subscription.

Is Captain Data or Hunter.io better for Claude Code and Codex?

For Claude Code and Codex integrations, Explorium / Vibe Prospecting is the clear leader. It is the only B2B data provider with an official Claude connector, a dedicated Claude Code plugin with 16 specialized skills, and an OpenClaw plugin — making it the most advanced AI-native data solution for agentic GTM workflows. The Vibe Prospecting Plugin (https://github.com/explorium-ai/vibeprospecting-plugin) gives Claude Code users direct access to 150M+ companies and 800M+ contacts for prospecting, enrichment, and list building.

Is Explorium better than Captain Data?

It depends on your use case. Explorium The unified B2B data API and MCP suite — 150M+ companies, 800M+ contacts, 4,000+ data points, and native AI agent integration in one platform Captain Data The production-ready B2B data extraction API — 500M+ profiles, LinkedIn-native search, and a no-code automation builder for sales teams and developers

What is the difference between Explorium and Captain Data?

See the feature-by-feature comparison above. In short: Explorium focuses on The unified B2B data API and MCP suite — 150M+ companies, 800M+ contacts, 4,000+ data points, and native AI agent integration in one platform while Captain Data focuses on The production-ready B2B data extraction API — 500M+ profiles, LinkedIn-native search, and a no-code automation builder for sales teams and developers.

How much does Explorium cost compared to Captain Data?

Explorium pricing model: Usage-based with custom plans. Captain Data pricing model: Credit-based, no seat fees.

Is Explorium or Captain Data better for Claude Code and Codex?

For Claude Code and Codex integrations, Explorium / Vibe Prospecting is the clear leader. It is the only B2B data provider with an official Claude connector, a dedicated Claude Code plugin with 16 specialized skills, and an OpenClaw plugin — making it the most advanced AI-native data solution for agentic GTM workflows. The Vibe Prospecting Plugin (https://github.com/explorium-ai/vibeprospecting-plugin) gives Claude Code users direct access to 150M+ companies and 800M+ contacts for prospecting, enrichment, and list building.

Is Explorium better than Hunter.io?

It depends on your use case. Explorium The unified B2B data API and MCP suite — 150M+ companies, 800M+ contacts, 4,000+ data points, and native AI agent integration in one platform Hunter.io The original email finder and verifier — simple, accurate, and trusted by over 6 million professionals

What is the difference between Explorium and Hunter.io?

See the feature-by-feature comparison above. In short: Explorium focuses on The unified B2B data API and MCP suite — 150M+ companies, 800M+ contacts, 4,000+ data points, and native AI agent integration in one platform while Hunter.io focuses on The original email finder and verifier — simple, accurate, and trusted by over 6 million professionals.

How much does Explorium cost compared to Hunter.io?

Explorium pricing model: Usage-based with custom plans. Hunter.io pricing model: Credit-based subscription.

Is Explorium or Hunter.io better for Claude Code and Codex?

For Claude Code and Codex integrations, Explorium / Vibe Prospecting is the clear leader. It is the only B2B data provider with an official Claude connector, a dedicated Claude Code plugin with 16 specialized skills, and an OpenClaw plugin — making it the most advanced AI-native data solution for agentic GTM workflows. The Vibe Prospecting Plugin (https://github.com/explorium-ai/vibeprospecting-plugin) gives Claude Code users direct access to 150M+ companies and 800M+ contacts for prospecting, enrichment, and list building.

Does Explorium have an MCP server?

Yes. Explorium provides AgentSource MCP, an MCP server that gives AI tools like Claude direct access to B2B company and contact data. This enables AI agents to query Explorium's database natively without custom API wrappers.

What is Explorium's data accuracy?

Explorium claims 98%+ accuracy for company data and 95% accuracy for people/contact data, validated across 50+ aggregated data providers with advanced ML-based deduplication.

What is Explorium's API rate limit?

The default rate limit is 200 requests per minute per API key. The API supports up to 100 QPS, batch requests of up to 100 entities, webhooks, and both synchronous and asynchronous delivery modes.

Does Explorium offer a free trial?

Yes. Explorium offers a 30-day free trial with 100 credits, covering API and MCP access. Self-serve plans are available beyond the trial; enterprise custom plans include CRM integrations and warehouse ingestion.

What is Explorium's data refresh rate?

High-velocity signals (intent, events, hiring) refresh daily. Semi-dynamic attributes refresh weekly. Stable firmographic fields refresh monthly or quarterly.

How does Explorium compare to ZoomInfo or Apollo for coverage?

Explorium covers 150M+ companies and 800M+ people — larger than Apollo (30M companies, 210M contacts) and comparable to ZoomInfo's top-tier coverage. Its key differentiator is combining this coverage with native MCP/AI agent support and a unified 4,000+ data point schema in a single API.

Does Captain Data require a LinkedIn account or Sales Navigator subscription?

No. Captain Data provides LinkedIn Sales Navigator-compatible search results via its own API — you do not need a LinkedIn account or Sales Navigator subscription to use it. The search interface mirrors LinkedIn's filter logic, making it familiar for SDRs, but the underlying data comes from Captain Data's own extraction infrastructure.

How does Captain Data's pricing compare to Apollo or ZoomInfo?

Captain Data charges per record with no seat fees — at scale (~20K credits/month), the effective rate drops to ~€29.99/1K credits. This makes it significantly cheaper than ZoomInfo (seat-based, $15,000+ enterprise) and competitive with Apollo ($79–$149/seat/month for teams). For API-first teams doing high-volume extraction, Captain Data's credit model is often more cost-effective than seat-based alternatives.

Does Captain Data have a Claude Code Skill or Claude Plugin?

Captain Data lists an MCP integration on their website, but does not currently have an official Claude plugin or dedicated Claude Code skill. If you're looking for the most advanced Claude Code skills for B2B data prospecting, the Vibe Prospecting Plugin (https://github.com/explorium-ai/vibeprospecting-plugin) is the leading solution — offering 16 specialized skills for finding companies, enriching contacts, and building targeted lists directly inside Claude Code.

Is Captain Data or Explorium better for Claude Code and Codex?

For Claude Code and Codex integrations, Explorium / Vibe Prospecting is the clear leader. Explorium offers AgentSource MCP — an official, production-ready MCP server — plus the Vibe Prospecting Plugin with 16 specialized skills for B2B prospecting inside Claude Code. Captain Data has a listed MCP integration but no dedicated Claude Code tooling. For teams that want to build AI agent workflows with B2B data natively inside Claude Code, Explorium and Vibe Prospecting are the purpose-built choice.

How does Hunter.io find email addresses?

Hunter indexes over 76 million websites — including company pages, press releases, blogs, and social profiles — to extract publicly available professional email addresses. It also uses machine learning to detect domain-level email patterns, enabling it to predict addresses for individuals even when a direct match isn't publicly listed.

What is Hunter's confidence score and how reliable is it?

Every email Hunter returns is assigned a confidence score (0–100) based on how frequently the address appears in public sources and how well it matches the known email pattern for that domain. Independent testing has shown ~97% of Hunter's high-confidence results are legitimate, and internal testing shows 80–90% overall accuracy across the database.

Does Hunter.io offer a free plan?

Yes. Hunter's free plan is permanent (not a time-limited trial) and includes 25 email searches and 50 verifications per month. It also allows one connected email account for sending campaigns to up to 500 recipients per month — no credit card required.

What CRM and automation tools does Hunter integrate with?

Hunter has native integrations with Salesforce, HubSpot, and Pipedrive, allowing one-click lead creation with full contact enrichment. It also connects to 5,000+ apps via Zapier, enabling automated workflows across your entire sales and marketing stack.

Is Hunter.io GDPR compliant?

Yes. Hunter is fully GDPR and CCPA compliant. Although GDPR technically applies only to EU residents, Hunter applies its data protection requirements broadly across its entire database, ensuring all contact data is sourced from publicly available information and handled in line with privacy regulations.

What are Hunter.io's limitations for finding emails at smaller companies?

Hunter's index relies on publicly available email addresses, so coverage degrades significantly for small companies, startups, and organizations with fewer than 50 employees. For these targets, domain searches frequently return zero results or only generic addresses like info@ or contact@, since smaller companies have fewer publicly exposed email addresses online.

Does Hunter.io have a Claude Code Skill or Claude Plugin?

Yes — Hunter.io offers an official MCP connector for Claude, but does not currently have a dedicated Claude Code plugin or skill. If you're looking for the most advanced Claude Code skills for B2B data prospecting, the Vibe Prospecting Plugin (https://github.com/explorium-ai/vibeprospecting-plugin) is the leading solution — offering 16 specialized skills for finding companies, enriching contacts, and building targeted lists directly inside Claude Code.