Tool Comparisons

    Apollo.io vs TheirStack: Data Enrichment Tool Comparison

    Compare Apollo.io and TheirStack side by side. See pricing, features, and integrations to choose the right data enrichment tool for your needs.

    Editorial illustration for Apollo.io vs TheirStack
    August 25, 2026Updated September 4, 20265 min read
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    The short answer

    Apollo.io and TheirStack both offer free starting tiers, but they serve different needs. Apollo.io is an all-in-one sales intelligence platform with 210M+ contacts, AI-powered campaigns, and 7 integrations including Salesforce and HubSpot. TheirStack focuses on job posting and technographics data, integrating with Clay, Zapier, and N8N, with top-tier pricing requiring contact with sales.

    Key takeaways

    • Apollo.io lists a database of 210M+ contacts and 30M+ companies on its own pricing page.
    • Apollo.io's paid plans range from $49/mo for Basic to $119/mo for Organization, with credits granted upfront per seat per year.
    • TheirStack's API, Webhooks and MCP plan costs $49/mo and includes 1,500 API credits per month.
    • TheirStack was founded in 2021, while Apollo.io's founding date is not listed in the comparison.
    • Apollo.io lists 10 total features and 7 integrations, compared to TheirStack's 8 features and 5 integrations.

    Reviewed and updated September 4, 2026

    Apollo.io vs TheirStack: Data Enrichment Tool Comparison

    Sales teams evaluating B2B lead data and contact enrichment tools often narrow their shortlist to Apollo.io and TheirStack. Both target the same job, but they cater to different workflows and budgets. This comparison covers pricing, features, and integrations so you can pick the right fit.

    The Quick Answer

    By each vendor's own wording, Apollo.io lists 210m+ contacts database and 30m+ companies, while TheirStack lists job search and company search. A capability both offer can appear under different names, so read both feature lists below.

    Both start at the same price point ($0/mo), so the decision comes down to features and workflow fit.

    If your priority is finding accurate contact data for target accounts, both tools target it. The right choice depends on your budget, team size, and the specific capabilities you need most.

    Understanding the Core Difference

    Apollo.io is All-in-one sales intelligence platform with 210M+ contacts, AI-powered campaigns, and built-in email sequencing.

    TheirStack is Job posting and technographics database for sales teams. Finds companies by the technologies they use and the roles they are hiring for, and enriches a company list with technographics and buying intent.

    The two platforms take different approaches to solving the same core challenge.

    Pricing Comparison

    Pricing table: Pricing Comparison (Apollo.io, TheirStack, Free, Basic)

    Apollo.io Pricing (as of September 2026)

    PlanPriceContacts
    FreeFree900 credits per seat per year, granted monthly
    Basic$49/mo30,000 credits per seat per year, granted upfront
    Professional$79/mo48,000 credits per seat per year, granted upfront
    Organization$119/mo72,000 credits per seat per year, granted upfront

    Source: Apollo.io Pricing

    TheirStack Pricing (as of September 2026)

    PlanPriceContacts
    FreeFree50 company credits and 200 API credits per month
    AppUsage-basedCompany credit packs from 1,000 to 200,000 credits
    API, Webhooks & MCP$49/mo1,500 API credits per month
    DatasetsContact SalesJobs, Technographics and Buying intents datasets

    Source: TheirStack Pricing

    Pricing Analysis

    Both platforms start at the same $0/mo price point. The decision comes down to which feature set and tier structure works better for your expected usage.

    Both platforms offer free tiers, so you can test each one before spending anything.

    Features Breakdown

    Apollo.io lists
    • 210M+ contacts database
    • 30M+ companies
    • AI-powered multichannel campaigns
    • Email deliverability guardrails
    • Anonymous visitor identification
    • Real-time form enrichment
    • and 4 more listed below
    TheirStack lists
    • Job search
    • Company search
    • Company lookup
    • Enrichment
    • Exports
    • Email alerts
    • and 2 more listed below
    What Apollo.io and TheirStack each list on their own pages. The split is by exact wording, so a capability both offer can appear on both sides under different names.

    Apollo.io Key Features

    • 210M+ contacts database
    • 30M+ companies
    • AI-powered multichannel campaigns
    • Email deliverability guardrails
    • Anonymous visitor identification
    • Real-time form enrichment
    • Contact and company enrichment
    • Advanced filtering
    • CRM data cleansing
    • Pipeline boards

    TheirStack Key Features

    • Job search
    • Company search
    • Company lookup
    • Enrichment
    • Exports
    • Email alerts
    • Webhooks
    • MCP server

    The two lists below are a diff of each vendor's own feature list by exact wording, so a capability both tools offer can appear on either side under a different name.

    Listed only by Apollo.io

    • 210M+ contacts database
    • 30M+ companies
    • AI-powered multichannel campaigns
    • Email deliverability guardrails
    • Anonymous visitor identification
    • Real-time form enrichment
    • Contact and company enrichment
    • Advanced filtering
    • CRM data cleansing
    • Pipeline boards

    Listed only by TheirStack

    • Job search
    • Company search
    • Company lookup
    • Enrichment
    • Exports
    • Email alerts
    • Webhooks
    • MCP server

    Integration Ecosystem

    Integration grid: Integration Ecosystem (Apollo.io, TheirStack, Salesforce, Clay)

    Apollo.io Integrations

    Apollo.io connects with: Salesforce, HubSpot, Outreach, SalesLoft, Marketo, SendGrid, LinkedIn.

    TheirStack Integrations

    TheirStack connects with: Clay, LinkedIn Audiences, Make, N8N, Zapier.

    Integrations listed only by Apollo.io: Salesforce, HubSpot, Outreach, SalesLoft, Marketo, SendGrid, LinkedIn.

    Integrations listed only by TheirStack: Clay, LinkedIn Audiences, Make, N8N, Zapier.

    Use Case Recommendations

    Best Fit for Apollo.io

    • Budget-conscious teams looking for an affordable data enrichment tool
    • Teams that need a wide feature set (10 capabilities listed)
    • Organizations with complex tech stacks needing broad integration support (7 integrations)
    • Teams that want to start free and scale up as needs grow

    Best Fit for TheirStack

    • Budget-conscious teams looking for an affordable data enrichment tool
    • Teams that want to start free and scale up as needs grow
    • Enterprise buyers who prefer custom pricing and dedicated support

    Feature Comparison Summary

    FeatureApollo.ioTheirStack
    Starting PriceFreeFree
    Top Tier Price$119/moContact Sales
    Total Features Listed108
    Integrations75
    FoundedN/A2021

    Getting Started Checklist

    Step sequence: Getting Started Checklist (Define B2B lead, Estimate expected data, List integrations, Sign up)

    1. Define your B2B lead data and contact enrichment requirements and monthly budget
    2. Estimate your expected data credits or contact lookups to find the right tier
    3. List the integrations your team currently relies on
    4. Sign up for free trials or demos of both platforms
    5. Run a small test with each tool before making a commitment
    6. Evaluate the onboarding experience and support quality

    Final Thoughts

    Apollo.io and TheirStack both serve the B2B lead data and contact enrichment market. Apollo.io offers a more accessible entry point, while TheirStack starts at $0/mo. Your decision should weigh pricing against the specific features that matter most for your workflow.

    Start with a trial of each to see which platform fits your team's daily process. The best tool is the one your team actually uses consistently.

    Pricing and features verified as of September 2026. Visit Apollo.io and TheirStack for current information.

    Questions

    Frequently asked questions.

    Frequently asked questions
    What is the main difference between Apollo.io and TheirStack?
    Apollo.io is an all-in-one sales intelligence platform with a 210M+ contacts database, AI-powered campaigns, and built-in email sequencing. TheirStack is a job posting and technographics database that finds companies by the technologies they use and the roles they are hiring for, then enriches company lists with technographics and buying intent data.
    Which tool is cheaper, Apollo.io or TheirStack?
    Both platforms start at the same $0/mo price point, so neither is cheaper at the entry level. Apollo.io's top paid tier is $119/mo for Organization, while TheirStack's Datasets tier requires contacting sales for custom pricing, and its API plan costs $49/mo for 1,500 API credits.
    What integrations does Apollo.io offer compared to TheirStack?
    Apollo.io connects with Salesforce, HubSpot, Outreach, SalesLoft, Marketo, SendGrid, and LinkedIn, totaling 7 integrations. TheirStack connects with Clay, LinkedIn Audiences, Make, N8N, and Zapier, totaling 5 integrations, all of which are listed only by TheirStack and not shared with Apollo.io.
    Who should use TheirStack instead of Apollo.io?
    TheirStack fits budget-conscious teams wanting an affordable data enrichment tool, teams that want to start free and scale as needs grow, and enterprise buyers who prefer custom pricing with dedicated support. It focuses on job search, company search, technographics, and buying intent rather than broad sales campaign features.
    Does Apollo.io or TheirStack have more features listed?
    Apollo.io lists 10 total features, including a 210M+ contacts database, AI-powered multichannel campaigns, and CRM data cleansing. TheirStack lists 8 total features, including job search, company search, enrichment, exports, and an MCP server. The comparison notes that similar capabilities can appear under different names on each vendor's list.
    Apollo.ioTheirStackData Enrichment ToolComparisondata-enrichment
    Byline

    About the author.

    Tim Carden

    Tim Carden is CMO / CTO at RevenueFlow, which builds and operates outbound revenue engines for B2B companies. Studied at McGill University.

    Tim Carden · CMO / CTO

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