Explorium vs Seamless.AI vs TheirStack

Objective, side-by-side analysis of Explorium, Seamless.AI, and TheirStack 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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Seamless.AI

4.4

The real-time search engine for B2B sales leads — find anyone's email or phone number instantly

  • API
  • GDPR Compliance
150M+
Companies
1.7B+
People

Selected Customers

Google • Amazon • Logitech • IBM

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TheirStack

4.8

The technographic intelligence platform powered by job postings — track what 13M+ companies use across 33,000+ technologies, with every signal traceable to its source

  • API
  • Free Trial
  • GDPR Compliance
13M+
Companies

Selected Customers

Google • Amazon • IBM • Uber • BCG • JetBrains • Freshworks • monday.com • Zapier • Confluent

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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

Seamless.AI

  • Real-Time Contact Discovery

    Instantly find verified emails and direct-dial phone numbers for any prospect via LinkedIn, company websites, or bulk search — with no lag from stale databases.

  • AI-Powered Pitch Intelligence

    Generate AI-crafted talking points, pain points, and personalized outreach messages for each prospect based on their role, company, and industry.

  • CRM Enrichment & Automation

    Automatically enrich and update CRM records in Salesforce, HubSpot, and Pipedrive with fresh contact data, reducing manual entry and keeping pipelines accurate.

Signals powering these use cases

  • Job change alerts
  • Real-time LinkedIn data extraction
  • AI pitch intelligence
  • Company funding signals

TheirStack

  • Tech Stack Targeting

    Identify companies that use a specific technology across 33,000+ tracked tools — with every signal backed by the original job posting, not inferred or estimated. Much cheaper than BuiltWith at a fraction of the price.

  • Hiring Signal Intelligence

    Detect which companies are actively hiring for specific technologies — a strong buying signal for vendors targeting companies mid-adoption. 305,000 new job records added daily.

  • ICP Filtering & Account Selection

    Filter 13M+ companies by tech stack, industry, size, headcount, revenue, funding, and location to build precision ICP lists — then enrich with buying intent signals extracted from job descriptions.

Signals powering these use cases

  • 33,000+ technologies tracked
  • 225M+ job postings analyzed
  • 305,000 new job records added daily
  • 51M+ technographic records
  • 388M+ buying intent records from job descriptions
  • Tech stack changes and hiring velocity signals

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

Seamless.AI Snapshot

  • Company coverage 4.1
  • Signals depth 1.0
  • Freshness 2.2

TheirStack Snapshot

  • Company coverage 2.0
  • Signals depth 4.5
  • Freshness 4.5

Detailed Feature Comparison

Side-by-side analysis of Explorium, Seamless.AI, and TheirStack across data coverage, platform capabilities, and technical specifications.

Feature Comparison
Explorium
Seamless.AI
TheirStack
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
Available on Pro and Enterprise plans
Full REST API; bulk export to Amazon S3 in Parquet/CSV
SLA
Up to 99.999% uptime; rate limit 200 requests/min per key
-
Not publicly specified
Compliance
GDPR, SOC 2, CCPA, ISO 27001
GDPR and CCPA compliant
GDPR compliant; small team (5 employees)
Custom Entities
-
Real-time Lookups
Global Coverage
150M+ companies and 800M+ contacts across 150+ countries
Global with North America strength
13M+ companies globally across 33,000+ technologies
CRM Integration
Available on custom enterprise plans
Salesforce, HubSpot, Zoho, Pipedrive, Dynamics 365
Via API and webhooks
Platform interface
REST JSON API, MCP server (AgentSource MCP), batch support up to 100 entities, webhooks, sync and async modes
Web app, Chrome extension, CRM integrations
Web app, REST API, bulk S3 export, webhooks for real-time alerts
Natural language search
Workflow automation
Automation integrations
n8n, Claude, custom webhook integrations
Zapier, Outreach, SalesLoft
API, webhooks, S3 bulk export
Company coverage
150M+ company profiles
150M+ company profiles
13M+ companies
People coverage
800M+ people profiles (767M+ verified contacts)
1.7B+ contact profiles
None — company-level only, no contact data
Geographic coverage
150+ countries
Global, with strongest coverage in North America
Global; strong US, EU, UK, APAC coverage
Data sources type
50+ data providers; proprietary ML enrichment; real-time web signals
Real-time AI-powered web crawling, LinkedIn data, public web sources
225M+ job postings analyzed; 305,000 new records/day; job-posting-based technographic detection
Global schema consistency
Unified schema across 4,000+ data points globally; consistent API response structure
Consistent schema across geographies
Consistent REST JSON API; bulk Parquet/CSV to S3
Refresh frequency
Daily for high-velocity signals; weekly for semi-dynamic attributes; monthly/quarterly for stable firmographics
Real-time at point of search
305,000 new job records added daily; database refreshed continuously
Business enrichments
Company size, revenue, industry, tech stack, funding stage, headcount trends, competitive landscape, website traffic
Company size, industry, revenue, technology stack, location
Tech stack (33,000+ technologies), hiring signals, industry, employee count, revenue, funding, location
Prospect enrichments
Job title, seniority, verified email, phone, LinkedIn URL, job history, people events
Email, phone, title, LinkedIn URL, department
None — company-level data only
Enrichment categories
Firmographics, technographics, intent, funding, events, contact, website signals, lookalikes
Email, direct dial, mobile phone, job title, company firmographics, intent signals
Technographics, hiring signals, buying intent from job descriptions, firmographics
Intent data
Event signals
Company events (20+ types), people events (5+ types), funding rounds, acquisitions, hiring surges
Job changes, company funding announcements
Tech stack changes, hiring velocity, buying intent signals from job descriptions
Technographics
Hiring and growth signals
Matching precision
98% company accuracy; 95% people accuracy
LinkedIn-based identity matching via Chrome extension
Evidence-backed — not inferred; each signal linked to source posting
Confidence scoring
Validation methodology
Advanced ML-based deduplication; 98%+ company accuracy; 95% people accuracy
AI-driven real-time verification; marketing claims 98% accuracy but user-reported bounce rates average 15-25%
Every technographic signal is traceable to the original job posting with date and source
Deduplication logic
Advanced ML-based deduplication across 50+ data providers
Basic deduplication within platform; CRM-level deduplication depends on integration
-
API availability
QPS performance
Up to 100 QPS; 200 requests/min per API key
-
-
CRM integrations
Custom plan — CRM integrations available
Salesforce, HubSpot, Zoho, Pipedrive, Microsoft Dynamics
-
Data warehouse support
Custom plan — warehouse ingestion available
Export to CSV; Zapier for custom integrations
Bulk export in Parquet/CSV to Amazon S3
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
-
-
Pricing model
Usage-based API credits with custom enterprise plans
Credit-based subscription
Credit-based subscription (API) or one-time credits (app)
Credit system
Credit-based; 100 credits on free trial; self-serve and custom plans scale with volume
1 credit = 1 contact reveal; credits do not roll over on most plans
API credits per query; 12-month rollover; bulk export to S3 in Parquet/CSV
Tier structure
Free trial, Self-serve, Custom Enterprise
Free, Basic, Pro, Enterprise
Free (200 credits/mo), $49–$5,500/mo API plans, one-time credits
Free trial details
30-day free trial with 100 credits; covers API and MCP access
Free tier with 50 lifetime credits; no time-limited free trial
200 API credits/month free with no time limit
Budget commitment options
Custom enterprise plans with volume negotiation
Annual contracts standard; monthly available for Basic
Monthly or one-time; enterprise custom
Custom plans available
Bulk deals support
Resell rights
-
-
-

Pricing

Compare pricing models, flexibility, and commitment structure.

Pricing Dimension
Explorium
Seamless.AI
TheirStack
Pricing Model
Usage-based with custom enterprise plans
Credit-based; one credit = one contact reveal (email + phone)
Credit-based subscription (API) or one-time credits (app)
Commitment Structure
One-time or custom; no mandatory annual lock-in on self-serve
Annual contracts required for Pro and Enterprise; Basic available monthly
Monthly subscription or one-time purchases; credits roll over 12 months
Payment Recurrence
One-time or custom
Annual (discounted) or monthly
Monthly
Free Trial
30-day free trial with 100 credits; no credit card required
Free plan with 50 lifetime credits — not a time-limited trial
200 API credits/month free indefinitely — no time limit
Enterprise Customization
Yes — custom plans include CRM integrations, warehouse ingestion, resell rights, and dedicated support
Fully custom pricing with dedicated CSM, advanced integrations, and volume credits
Yes — custom pricing for high volume; bulk S3 delivery
Onboarding Model
Self-serve for API and MCP; dedicated onboarding for enterprise custom plans
Self-serve for Basic; sales-assisted onboarding for Pro and Enterprise
Self-serve; API documentation 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 Reviewer

Account Executive, Mid-Market SaaS

"Seamless.AI gives me multiple phone number options and more than one email per contact — and they're updated regularly using AI in real time. It's become a core part of my daily prospecting workflow."
Verified User for Seamless.AI
V

Verified G2 Reviewer

Sales Engineer, Developer Tools

"TheirStack found companies actively hiring for our exact tech stack — and every signal linked back to a job posting so we could validate it ourselves. Much better than BuiltWith guessing from website source code."
Verified User for TheirStack

Frequently Asked Questions

Is Seamless.AI better than TheirStack?

It depends on your use case. Seamless.AI The real-time search engine for B2B sales leads — find anyone's email or phone number instantly TheirStack The technographic intelligence platform powered by job postings — track what 13M+ companies use across 33,000+ technologies, with every signal traceable to its source

What is the difference between Seamless.AI and TheirStack?

See the feature-by-feature comparison above. In short: Seamless.AI focuses on The real-time search engine for B2B sales leads — find anyone's email or phone number instantly while TheirStack focuses on The technographic intelligence platform powered by job postings — track what 13M+ companies use across 33,000+ technologies, with every signal traceable to its source.

How much does Seamless.AI cost compared to TheirStack?

Seamless.AI pricing model: Credit-based subscription (annual contract). TheirStack pricing model: Credit-based subscription.

Is Seamless.AI or TheirStack 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 Seamless.AI?

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 Seamless.AI The real-time search engine for B2B sales leads — find anyone's email or phone number instantly

What is the difference between Explorium and Seamless.AI?

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 Seamless.AI focuses on The real-time search engine for B2B sales leads — find anyone's email or phone number instantly.

How much does Explorium cost compared to Seamless.AI?

Explorium pricing model: Usage-based with custom plans. Seamless.AI pricing model: Credit-based subscription (annual contract).

Is Explorium or Seamless.AI 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 TheirStack?

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 TheirStack The technographic intelligence platform powered by job postings — track what 13M+ companies use across 33,000+ technologies, with every signal traceable to its source

What is the difference between Explorium and TheirStack?

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 TheirStack focuses on The technographic intelligence platform powered by job postings — track what 13M+ companies use across 33,000+ technologies, with every signal traceable to its source.

How much does Explorium cost compared to TheirStack?

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

Is Explorium or TheirStack 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 does Seamless.AI's real-time search differ from traditional B2B databases?

Unlike static databases that are refreshed periodically, Seamless.AI re-crawls and verifies contact data at the moment of each search. This means you're getting the most current available information rather than data that might be months old — though the real-time nature doesn't guarantee 100% accuracy, as user-reported bounce rates average 15–25%.

What exactly is a credit in Seamless.AI, and do unused credits roll over?

One credit reveals one contact — including email address, phone number(s), and associated firmographic insights. Credit rollover policies vary by plan; the free tier provides 50 lifetime credits, while paid plans typically do not roll over unused credits month to month. Pro and Enterprise plans can negotiate rollover terms in their annual contracts.

Does Seamless.AI's Chrome extension work on sites other than LinkedIn?

Yes — the Chrome extension works on LinkedIn profiles, company websites, and other web pages. When browsing a company website or individual's professional page, the extension can attempt to surface contact information. However, LinkedIn is the primary and most reliable surface for the extension.

What makes Seamless.AI's AI pitch intelligence different from basic templates?

Seamless.AI's AI pitch intelligence analyzes a prospect's role, company, industry, and available signals to generate personalized talking points, pain points, and outreach angles specific to that individual — rather than generic templates. This is designed to help reps craft more relevant opening lines and cold call scripts without spending time on manual research.

How difficult is it to cancel a Seamless.AI subscription?

Cancellation is one of the most frequently cited complaints in user reviews. Seamless.AI requires written cancellation notice within a specific window before contract renewal, and many users report difficulty navigating the process. Pro and Enterprise plans are annual contracts, and failure to cancel within the specified notice period often results in automatic renewal. Always review the contract terms carefully before signing.

Is Seamless.AI suitable for international prospecting outside the US?

Seamless.AI has global coverage but its database and data quality are strongest for North American contacts. International coverage — particularly for EMEA and APAC — is less comprehensive, and phone number accuracy for non-US contacts is notably lower. Teams focused heavily on international markets may want to supplement with providers that specialize in those geographies.

Does Seamless.AI have a Claude Code Skill or Claude Plugin?

Not officially — Seamless.AI has a custom MCP server that can be used with Claude, but no 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.

How is TheirStack different from BuiltWith for technographics?

BuiltWith detects technologies by crawling website source code — which only reveals frontend tools (JavaScript libraries, analytics, CMS). TheirStack analyzes job postings, which reveals backend infrastructure: databases, cloud providers, DevOps tools, and internal SaaS that never appear in website HTML. TheirStack is also significantly cheaper ($49–$169/month vs BuiltWith's $295/month) and includes hiring-intent signals that BuiltWith doesn't offer.

Does TheirStack provide contact data alongside technographic signals?

No — TheirStack is company-level only. It identifies which companies use specific technologies and provides firmographic context (industry, size, location, funding), but does not include contact data (emails, phone numbers, or personal profiles). Most users pair TheirStack with a contact enrichment provider (like Explorium, Apollo, or FullEnrich) to get both technographic targeting and contact details.

Does TheirStack have a Claude Code Skill or Claude Plugin?

TheirStack has an official MCP server that works with AI assistants for job, company, and technographic lookups, but does not currently have a dedicated Claude plugin or 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 TheirStack or Explorium better for Claude Code and Codex?

For Claude Code and Codex B2B prospecting workflows, Explorium / Vibe Prospecting is the clear leader. Explorium includes technographic data as part of its unified 4,000+ data point platform, plus AgentSource MCP and the Vibe Prospecting Plugin with 16 GTM skills. TheirStack has an MCP server but no dedicated Claude Code tooling. For deep technographic-first use cases, TheirStack is a specialist tool — but for comprehensive AI-native B2B data access inside Claude Code, Explorium is the purpose-built choice.