MillionVerifier vs TheirStack: Data Enrichment Tool Comparison
Compare MillionVerifier and TheirStack side by side. See pricing, features, and integrations to choose the right data enrichment tool for your needs.
MillionVerifier is a bulk email verification service that cleans lists and validates addresses in real time, while TheirStack is a job posting and technographics database that finds companies by tech stack and hiring activity. Both offer free starting tiers. MillionVerifier lists 10 integrations and 2 pricing tiers, TheirStack lists 5 integrations and 4 pricing tiers, and TheirStack was founded in 2021.
Key takeaways
- Both MillionVerifier and TheirStack offer a free tier starting at $0/mo.
- TheirStack offers 4 pricing tiers compared to MillionVerifier's 2 tiers.
- MillionVerifier integrates with 10 platforms, including Mailchimp, Hubspot, Zoho CRM, and Mailgun.
- TheirStack integrates with 5 platforms, including Clay, LinkedIn Audiences, Make, N8N, and Zapier.
- TheirStack's API, Webhooks and MCP tier costs $49/mo and includes 1,500 API credits per month.
Reviewed and updated September 4, 2026
MillionVerifier vs TheirStack: Data Enrichment Tool Comparison
MillionVerifier and TheirStack are both data enrichment tools. Choosing between them depends on your team size, budget, and specific B2B lead data and contact enrichment requirements. Here is what each vendor publishes about pricing, features, and integrations.
The Quick Answer
By each vendor's own wording, MillionVerifier lists email checker (single) and email list verification (csv), 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
MillionVerifier is Bulk email verification service that cleans uploaded lists, checks single addresses in real time and verifies through an API. Connects to email marketing platforms to import lists and remove bad addresses automatically.
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
MillionVerifier Pricing (as of September 2026)
| Plan | Price | Emails |
|---|---|---|
| Free account | Free | 100 free credits |
| Pay as you go | Usage-based | 50,000 emails |
Source: MillionVerifier Pricing
TheirStack Pricing (as of September 2026)
| Plan | Price | Contacts |
|---|---|---|
| Free | Free | 50 company credits and 200 API credits per month |
| App | Usage-based | Company credit packs from 1,000 to 200,000 credits |
| API, Webhooks & MCP | $49/mo | 1,500 API credits per month |
| Datasets | Contact Sales | Jobs, 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.
TheirStack offers 4 pricing tiers compared to MillionVerifier's 2, giving you more granularity as you scale.
Both platforms offer free tiers, so you can test each one before spending anything.
Features Breakdown
- Email Checker (single)
- Email List Verification (CSV)
- Bulk Verifier
- Email Verifier API
- ESP integrations import
- Risky email refund
- and 2 more listed below
- Job search
- Company search
- Company lookup
- Enrichment
- Exports
- Email alerts
- and 2 more listed below
MillionVerifier Key Features
- Email Checker (single)
- Email List Verification (CSV)
- Bulk Verifier
- Email Verifier API
- ESP integrations import
- Risky email refund
- EverClean automatic email verification
- Credits never expire
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 MillionVerifier
- Email Checker (single)
- Email List Verification (CSV)
- Bulk Verifier
- Email Verifier API
- ESP integrations import
- Risky email refund
- EverClean automatic email verification
- Credits never expire
Listed only by TheirStack
- Job search
- Company search
- Company lookup
- Enrichment
- Exports
- Email alerts
- Webhooks
- MCP server
Integration Ecosystem
MillionVerifier Integrations
MillionVerifier connects with: Mailchimp, Hubspot, Zoho CRM, Getresponse, AWeber, MailerLite, Drip, Campaign Monitor, Mailgun, Mailjet.
TheirStack Integrations
TheirStack connects with: Clay, LinkedIn Audiences, Make, N8N, Zapier.
Integrations listed only by MillionVerifier: Mailchimp, Hubspot, Zoho CRM, Getresponse, AWeber, MailerLite, Drip, Campaign Monitor, Mailgun, Mailjet.
Integrations listed only by TheirStack: Clay, LinkedIn Audiences, Make, N8N, Zapier.
Use Case Recommendations
Best Fit for MillionVerifier
- Budget-conscious teams looking for an affordable data enrichment tool
- Organizations with complex tech stacks needing broad integration support (10 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
| Feature | MillionVerifier | TheirStack |
|---|---|---|
| Starting Price | Free | Free |
| Top Tier Price | Usage-based | Contact Sales |
| Total Features Listed | 8 | 8 |
| Integrations | 10 | 5 |
| Founded | N/A | 2021 |
Getting Started Checklist
- Define your B2B lead data and contact enrichment requirements and monthly budget
- Estimate your expected data credits or contact lookups to find the right tier
- List the integrations your team currently relies on
- Sign up for free trials or demos of both platforms
- Run a small test with each tool before making a commitment
- Evaluate the onboarding experience and support quality
Final Thoughts
MillionVerifier and TheirStack both serve the B2B lead data and contact enrichment market. MillionVerifier 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 MillionVerifier and TheirStack for current information.
Frequently asked questions.
Frequently asked questions- What's the core difference between MillionVerifier and TheirStack?
- MillionVerifier is a bulk email verification service that cleans uploaded lists, checks single addresses in real time, and verifies through an API. TheirStack is a job posting and technographics database that finds companies by the technologies they use and the roles they're hiring for, then enriches company lists with technographics and buying intent data.
- Is MillionVerifier or TheirStack cheaper?
- Both platforms start at the same price point, free, with $0/mo entry tiers. Beyond that, MillionVerifier moves to usage-based pay as you go pricing for 50,000 emails, while TheirStack has more tiers, including a $49/mo API, Webhooks and MCP plan and a Contact Sales tier for its datasets.
- Which tool has more integrations, MillionVerifier or TheirStack?
- MillionVerifier lists 10 integrations, including Mailchimp, Hubspot, Zoho CRM, Getresponse, AWeber, MailerLite, Drip, Campaign Monitor, Mailgun, and Mailjet. TheirStack lists 5 integrations: Clay, LinkedIn Audiences, Make, N8N, and Zapier. MillionVerifier offers broader integration coverage by count.
- Who is TheirStack best suited for?
- TheirStack fits budget-conscious teams looking for an affordable data enrichment tool, teams that want to start free and scale up as needs grow, and enterprise buyers who prefer custom pricing and dedicated support, since its Datasets tier is Contact Sales only.
- Who is MillionVerifier best suited for?
- MillionVerifier fits budget-conscious teams looking for an affordable data enrichment tool, organizations with complex tech stacks that need broad integration support across its 10 listed integrations, and teams that want to start free and scale usage as their needs grow.
About the author.
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
Connect on LinkedIn →Explore more.
Ready to scale your outreach?
We build GTM engines that book real meetings. See the receipts.
Related articles.
Apollo.io vs Proofy: Data Enrichment Tool Comparison
Compare Apollo.io and Proofy side by side. See pricing, features, and integrations to choose the right data enrichment tool for your needs.
AroundDeal vs Leadspicker: Data Enrichment Tool vs Sales Engagement Platform Comparison
Compare AroundDeal (data enrichment tool) and Leadspicker (sales engagement platform) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.
AroundDeal vs Salesflare: Data Enrichment Tool vs CRM Platform Comparison
Compare AroundDeal (data enrichment tool) and Salesflare (CRM platform) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.
Gong vs NeverBounce: Sales Engagement Platform vs Data Enrichment Tool Comparison
Gong vs NeverBounce: what Gong's own pages say about enrichment, what NeverBounce's API returns about an address, and how each vendor prices.
ContactOut vs Luru: Data Enrichment Tool vs Sales Engagement Platform Comparison
Compare ContactOut (data enrichment tool) and Luru (sales engagement platform) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.
Evaboot vs Microsoft Dynamics 365 Sales: Data Enrichment Tool vs CRM Platform Comparison
Compare Evaboot (data enrichment tool) and Microsoft Dynamics 365 Sales (CRM platform) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.