The Companies API vs TheirStack: Data Enrichment Tool Comparison

The Companies API vs TheirStack: Data Enrichment Tool Comparison

The Companies API and TheirStack compete head-to-head in the B2B lead data and contact enrichment space. This guide compares their pricing tiers, feature sets, and integration ecosystems to help you make a confident decision.

The Quick Answer

By each vendor's own wording, The Companies API lists domain to company profile enrichment and access to all 50m 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

The Companies API is The Companies API is a company enrichment API that turns a domain name into a structured company profile with firmographics such as industry, employee count, founding year and revenue across 50 million companies. Plans are monthly credit allowances with a request-rate limit.

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

The Companies API Pricing (as of September 2026)

Source: The Companies API Pricing

TheirStack Pricing (as of September 2026)

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

The Companies API lists

• Domain to company profile enrichment
• Access to all 50M companies
• Firmographics: industry, employee count, founding year, revenue
• Company lists
• Additional credits at a per-1,000 rate
• Rate-limited API by plan

TheirStack lists

• Job search
• Company search
• Company lookup
• Enrichment
• Exports
• Email alerts
• and 2 more listed below

The Companies API Key Features

• Domain to company profile enrichment
• Access to all 50M companies
• Firmographics: industry, employee count, founding year, revenue
• Company lists
• Additional credits at a per-1,000 rate
• Rate-limited API by plan

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 The Companies API

• Domain to company profile enrichment
• Access to all 50M companies
• Firmographics: industry, employee count, founding year, revenue
• Company lists
• Additional credits at a per-1,000 rate
• Rate-limited API by plan

Listed only by TheirStack

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

Integration Ecosystem

The Companies API Integrations

The Companies API connects with: .

TheirStack Integrations

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

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

Use Case Recommendations

Best Fit for The Companies API

• Budget-conscious teams looking for an affordable data enrichment tool
• Teams that want to start free and scale up as needs grow
• Revenue operations teams building targeted prospect lists
• Marketing teams enriching CRM data for segmentation

Best Fit for TheirStack

• Budget-conscious teams looking for an affordable data enrichment tool
• Teams that need a wide feature set (8 capabilities listed)
• Organizations with complex tech stacks needing broad integration support (5 integrations)
• Teams that want to start free and scale up as needs grow
• Enterprise buyers who prefer custom pricing and dedicated support

Feature Comparison Summary

Getting Started Checklist

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

The Companies API and TheirStack both serve the B2B lead data and contact enrichment market. The Companies API 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 The Companies API and TheirStack for current information.