Explorium vs Apollo.io vs Clearbit

Objective, side-by-side analysis of Explorium, Apollo.io, and Clearbit 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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Apollo.io

4.7

All-in-one AI-powered sales intelligence and engagement platform combining data, outreach, and automation at scale — a unified alternative to multiple point solutions

  • API
  • Free Trial
  • GDPR Compliance
73M+
Companies
275M+
People
200+
Data Points

Selected Customers

Autodesk • DocuSign • Customer.io • Census

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Clearbit

4.4

The data foundation for B2B go-to-market teams, combining 250+ data sources with ML processing to deliver firmographic, technographic, and contact-level enrichment natively inside HubSpot CRM

  • API
  • GDPR Compliance
200M+
Companies
500M+
People
100+
Data Points

Selected Customers

Intercom • Asana • Segment • Zendesk • Stripe • Atlassian

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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

Apollo.io

  • AI-Powered Prospecting

    Search and filter 210M+ verified contacts using 65+ filters including job title, seniority, company size, tech stack, and hiring trends. AI identifies and prioritizes best-fit prospects automatically.

  • Multichannel Sales Engagement

    Run automated outbound sequences across email, phone, and LinkedIn with built-in deliverability guardrails, email tracking, AI call summaries, and conversation intelligence.

  • Data Enrichment & Lead Routing

    Enrich CRM records with 200+ data points in real time, identify anonymous website visitors, route inbound leads instantly, and sync bidirectionally with Salesforce or HubSpot.

Signals powering these use cases

  • Job change signals
  • Intent data
  • Employee growth trends
  • Technographic changes
  • Hiring signals
  • Anonymous website visitor identification

Clearbit

  • Real-Time Data Enrichment

    Automatically enrich CRM contacts and company records with 100+ firmographic, demographic, and technographic attributes from 250+ data sources, refreshed every 30 days.

  • Anonymous Visitor Intelligence

    Clearbit Reveal uses IP matching across 4.5 billion mapped IPs to de-anonymize website traffic, surfacing buying intent signals and enabling real-time lead routing.

  • Lead Scoring & Form Optimization

    Power dynamic form shortening by pre-filling known fields via email-based enrichment, and apply enriched firmographic data to score and route inbound leads by ICP fit.

Signals powering these use cases

  • Anonymous website visitor identification via IP (Reveal)
  • Intent signals from website traffic
  • Technographic stack data
  • Corporate hierarchy mapping
  • Employee count and revenue range changes
  • Job title and role changes

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

Apollo.io Snapshot

  • Company coverage 2.1
  • Signals depth 3.5
  • Freshness 3.5

Clearbit Snapshot

  • Company coverage 2.8
  • Signals depth 3.5

Detailed Feature Comparison

Side-by-side analysis of Explorium, Apollo.io, and Clearbit across data coverage, platform capabilities, and technical specifications.

Feature Comparison
Explorium
Apollo.io
Clearbit
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
REST API on all plans; 50–200 calls/min by tier; docs at docs.apollo.io
Available; primarily through HubSpot ecosystem post-acquisition; standalone API limited for new customers
SLA
Up to 99.999% uptime; rate limit 200 requests/min per key
24-hour RTO/RPO; quarterly audits; annual third-party penetration testing
Not publicly documented post-HubSpot acquisition
Compliance
GDPR, SOC 2, CCPA, ISO 27001
GDPR, SOC 2 Type II, ISO/IEC 27001, CCPA; CASA compliant
GDPR, CCPA, SOC 2 certified; Trust Center and Privacy Request Form available
Custom Entities
-
-
Real-time Lookups
Global Coverage
150M+ companies and 800M+ contacts across 150+ countries
210M+ contacts globally; strongest in North America
Global company and contact coverage; 4.5B mapped IPs; EU suppression settings
CRM Integration
Available on custom enterprise plans
Bidirectional sync with Salesforce, HubSpot, Zoho; bulk invite and field mapping supported
Native HubSpot integration; Salesforce integration available
Platform interface
REST JSON API, MCP server (AgentSource MCP), batch support up to 100 entities, webhooks, sync and async modes
Web application (SaaS), Chrome extension for LinkedIn prospecting, REST API
Native HubSpot CRM UI; standalone dashboard deprecated for new users
Natural language search
-
Workflow automation
Automation integrations
n8n, Claude, custom webhook integrations
Zapier, Intercom, Zendesk, ServiceNow, Klaviyo, Salesloft, Outreach
Zapier, Tray.io, Segment (Twilio), Drift, Intercom, Qualified
Company coverage
150M+ company profiles
30M+ company profiles
50 million company records
People coverage
800M+ people profiles (767M+ verified contacts)
210M+ contact records
389 million contact records
Geographic coverage
150+ countries
Global; strongest in North America; international accuracy lower outside the US
Global; 4.5 billion mapped IPs for Reveal; EU GDPR suppression settings available
Data sources type
50+ data providers; proprietary ML enrichment; real-time web signals
Proprietary 2M+ contributor network, public web crawling, engagement suite signals, vetted third-party data providers
250+ public and proprietary sources: social profiles, company websites, legal filings, crowdsourced data
Global schema consistency
Unified schema across 4,000+ data points globally; consistent API response structure
Consistent schema with 65+ filters and 200+ fields globally; accuracy varies by region
Standardized role, seniority, and industry taxonomy (NAICS, GICS, SIC) applied globally
Refresh frequency
Daily for high-velocity signals; weekly for semi-dynamic attributes; monthly/quarterly for stable firmographics
Real-time when data signal captured; 150M contacts refreshed monthly; 72M emails verified monthly
Full dataset refresh every 30 days
Business enrichments
Company size, revenue, industry, tech stack, funding stage, headcount trends, competitive landscape, website traffic
Company size, revenue, industry, technology stack, funding stage, hiring trends, employee count growth
Employee count, revenue, industry (GICS/SIC/NAICS), tech stack, funding raised, market cap, corporate parent/hierarchy
Prospect enrichments
Job title, seniority, verified email, phone, LinkedIn URL, job history, people events
Job title, seniority, direct email, mobile phone, LinkedIn URL, job history, social profiles
Job title, standardized role and seniority, social profiles (LinkedIn, Twitter, GitHub), email, location, employment history
Enrichment categories
Firmographics, technographics, intent, funding, events, contact, website signals, lookalikes
Firmographics, technographics, demographics, intent data, hiring/growth signals, email verification, direct dials
Firmographic, technographic, demographic, corporate hierarchy, funding data
Intent data
Event signals
Company events (20+ types), people events (5+ types), funding rounds, acquisitions, hiring surges
Job changes, hiring signals, intent signals, anonymous website visitor activity
Anonymous visitor identification (Reveal), job title changes, employee count changes, new company registrations
Technographics
Hiring and growth signals
Matching precision
98% company accuracy; 95% people accuracy
91% stated email accuracy rate; multi-source matching across contributor network and public data
Email-based and domain-based matching; IP-based matching for Reveal (4.5B mapped IPs)
Confidence scoring
-
-
Validation methodology
Advanced ML-based deduplication; 98%+ company accuracy; 95% people accuracy
Proprietary 7-step email verification; real-time verification for bounces; network of 2M+ data contributors
Four-stage verification; ML algorithms; 2,500-person flexible QA team; 94% email deliverability
Deduplication logic
Advanced ML-based deduplication across 50+ data providers
CRM deduplication via native Salesforce and HubSpot sync with bidirectional updates
No charges for re-enriching previously enriched records within the same billing period
API availability
QPS performance
Up to 100 QPS; 200 requests/min per API key
200 API calls/min on paid plans; 50 calls/min on free plan
Historically ~10–20 req/sec; post-acquisition limits governed by credit system
CRM integrations
Custom plan — CRM integrations available
Salesforce, HubSpot, Zoho CRM (bidirectional sync)
HubSpot (native), Salesforce
Data warehouse support
Custom plan — warehouse ingestion available
CSV export available; direct warehouse connectors not prominently advertised
Batch enrichment available; Salesforce integration supported
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
ISO/IEC 27001
-
SLA uptime
Up to 99.999% uptime SLA
24-hour maximum RTO and RPO; quarterly security audits; annual penetration testing
Not publicly specified post-HubSpot acquisition
Pricing model
Usage-based API credits with custom enterprise plans
Per-seat subscription with tiered credit system for data exports
Credit-based, consumption model bundled with HubSpot subscription
Credit system
Credit-based; 100 credits on free trial; self-serve and custom plans scale with volume
Credits consumed on contact/company exports and data syncs; Free: 50/month; paid plans scale with tier
HubSpot Credits; 1 credit per contact or company enrichment; packs of 100/1,000/10,000
Tier structure
Free trial, Self-serve, Custom Enterprise
Free, Basic ($49/mo), Professional ($99/mo), Enterprise (custom)
Starter, Professional, Enterprise (mapped to HubSpot Customer Platform tiers)
Free trial details
30-day free trial with 100 credits; covers API and MCP access
Permanent free plan with 50 export credits and 5 mobile credits per month; nearly all features available
No free trial; no free plan; legacy free tools (Reveal Lite, TAM) sunset April 30, 2025
Budget commitment options
Custom enterprise plans with volume negotiation
Monthly or annual; enterprise volume negotiation available
Annual commitment with monthly billing; enterprise negotiated contracts
Custom plans available
Bulk deals support
Resell rights
-
-
-

Pricing

Compare pricing models, flexibility, and commitment structure.

Pricing Dimension
Explorium
Apollo.io
Clearbit
Pricing Model
Usage-based with custom enterprise plans
Per-seat subscription with credit-based data export limits
Credit-based consumption model bundled with HubSpot subscription
Commitment Structure
One-time or custom; no mandatory annual lock-in on self-serve
Monthly or annual; annual plans offered at a discount
Annual commitment for best pricing; monthly option available
Payment Recurrence
One-time or custom
Monthly or annual
Monthly billing with annual contract
Free Trial
30-day free trial with 100 credits; no credit card required
Free plan with 50 export credits and 5 mobile credits per month; no time limit
No free trial; legacy free tools sunset April 30, 2025
Enterprise Customization
Yes — custom plans include CRM integrations, warehouse ingestion, resell rights, and dedicated support
Yes — custom pricing, higher API rate limits, dedicated support, advanced compliance
Available via HubSpot Enterprise Customer Platform with custom pricing
Onboarding Model
Self-serve for API and MCP; dedicated onboarding for enterprise custom plans
Self-serve for Free/Basic/Professional; dedicated onboarding for Enterprise
Self-serve within HubSpot; sales-assisted for enterprise

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 Professional

"Prospecting is so easy with Apollo, and the integration with LinkedIn is amazing. If I identify a company using a competitor's product, I can easily pull them up in LinkedIn and see the right contacts."
Verified User for Apollo.io
V

Verified G2 User

Sales Operations Manager

"Clearbit summarized everything I needed about a contact before a meeting — saved me 30 minutes of prep. The HubSpot integration is seamless, but the credit system caught us off guard when automatic enrichment ran on our full database."
Verified User for Clearbit

Frequently Asked Questions

Is Apollo.io better than Clearbit?

It depends on your use case. Apollo.io All-in-one AI-powered sales intelligence and engagement platform combining data, outreach, and automation at scale — a unified alternative to multiple point solutions Clearbit The data foundation for B2B go-to-market teams, combining 250+ data sources with ML processing to deliver firmographic, technographic, and contact-level enrichment natively inside HubSpot CRM

What is the difference between Apollo.io and Clearbit?

See the feature-by-feature comparison above. In short: Apollo.io focuses on All-in-one AI-powered sales intelligence and engagement platform combining data, outreach, and automation at scale — a unified alternative to multiple point solutions while Clearbit focuses on The data foundation for B2B go-to-market teams, combining 250+ data sources with ML processing to deliver firmographic, technographic, and contact-level enrichment natively inside HubSpot CRM.

How much does Apollo.io cost compared to Clearbit?

Apollo.io pricing model: Per-seat subscription with credit-based exports. Clearbit pricing model: Credit-based (HubSpot Credits), requires paid HubSpot subscription.

Is Apollo.io or Clearbit 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 Apollo.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 Apollo.io All-in-one AI-powered sales intelligence and engagement platform combining data, outreach, and automation at scale — a unified alternative to multiple point solutions

What is the difference between Explorium and Apollo.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 Apollo.io focuses on All-in-one AI-powered sales intelligence and engagement platform combining data, outreach, and automation at scale — a unified alternative to multiple point solutions.

How much does Explorium cost compared to Apollo.io?

Explorium pricing model: Usage-based with custom plans. Apollo.io pricing model: Per-seat subscription with credit-based exports.

Is Explorium or Apollo.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 Clearbit?

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 Clearbit The data foundation for B2B go-to-market teams, combining 250+ data sources with ML processing to deliver firmographic, technographic, and contact-level enrichment natively inside HubSpot CRM

What is the difference between Explorium and Clearbit?

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 Clearbit focuses on The data foundation for B2B go-to-market teams, combining 250+ data sources with ML processing to deliver firmographic, technographic, and contact-level enrichment natively inside HubSpot CRM.

How much does Explorium cost compared to Clearbit?

Explorium pricing model: Usage-based with custom plans. Clearbit pricing model: Credit-based (HubSpot Credits), requires paid HubSpot subscription.

Is Explorium or Clearbit 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.

How accurate is Apollo.io's contact data?

Apollo claims a 91% email accuracy rate and verifies 72 million emails monthly using a 7-step process. 150 million contacts refresh monthly. Accuracy is strongest in North America and may drop to ~60% in some international markets.

Does Apollo.io offer API access?

Yes. Apollo's REST API is available on all plans including free. Free: 50 calls/min; paid plans: 200 calls/min. Enterprise plans can negotiate higher limits. Documentation at docs.apollo.io.

Is Apollo.io GDPR compliant?

Yes. Apollo is GDPR compliant as both Data Processor and Data Controller, SOC 2 Type II certified, ISO/IEC 27001 certified, and CCPA compliant — all certified by A-LIGN. Built-in tools help exclude EU prospects from outreach.

How does Apollo.io's credit system work?

Credits are consumed when exporting contacts to CSV or syncing to a CRM. Free plan: 50 export + 5 mobile credits/month. Basic ($49/mo) and Professional ($99/mo) include higher monthly allotments. Credits do not roll over. Enterprise plans offer custom volumes.

What integrations does Apollo.io support?

Native bidirectional CRM sync with Salesforce, HubSpot, and Zoho. Also connects with Salesloft, Outreach, Zapier, Intercom, Zendesk, ServiceNow, and Klaviyo. Chrome extension enables LinkedIn prospecting. Only one CRM can be connected at a time.

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

Yes — Apollo.io offers an official Claude Code plugin. 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.

Do I need a HubSpot subscription to use Clearbit in 2025?

Yes. Since HubSpot acquired Clearbit and rebranded it as Breeze Intelligence, all functionality requires a paid HubSpot subscription. Standalone access for new customers is no longer offered, and all legacy free tools were discontinued on April 30, 2025.

How does Clearbit's credit system work?

Clearbit operates on HubSpot Credits. Each contact or company enrichment consumes one credit. Credits reset monthly with no rollover. Re-enriching a previously enriched record within the same billing period does not consume additional credits.

How does Clearbit Reveal identify anonymous website visitors?

Reveal matches incoming website traffic against 4.5 billion mapped IP addresses to identify the company behind an anonymous visit, surfacing company name, industry, size, and location without requiring a form fill.

Is Clearbit GDPR compliant?

Yes. Clearbit is GDPR and CCPA compliant and SOC 2 certified. It offers EU suppression settings that prevent person-level enrichment for EU contacts. Individuals can submit data requests through Clearbit's Privacy Request Form.

How large is Clearbit's database?

50 million company records and 389 million contact profiles from 250+ data sources, refreshed every 30 days. 94% email deliverability reported across contact records.

Does Clearbit have a Claude Code Skill or Claude Plugin?

Clearbit does not currently offer a Claude plugin, skill, or MCP integration. 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.