Choose Apollo if you want one sales tool with its own database of 240M+ contacts and 30M+ accounts, plus sequences, dialling and AI agents that research and book meetings. Choose Clay if you want to build custom enrichment and outbound workflows that pull from 200+ data providers in one place, then send the results to your CRM, email tool or ad campaigns. Both have free plans, but Clay's is for building and testing, with 100 data credits a month and up to 200 rows per table.
Sales teams often treat these as rivals, but they're built differently. I read Clay's home and plans pages and Apollo's home, plans and about pages to see what each one does and what you get for free.
Clay and Apollo at a glance
| Clay | Apollo | |
|---|---|---|
| Core idea | Data infrastructure for building GTM workflows | An all-in-one AI GTM system |
| Where the data comes from | 200+ providers in one place, combined in waterfalls | Its own database of 240M+ contacts and 30M+ accounts |
| Outreach | Sends emails through Clay or an integration | Built-in prospecting, sequences and dialling |
| AI | Claygent research agent | Agents that research, build lists, write outreach and book meetings |
| Used by | 500,000+ GTM teams | 600,000+ companies |
| Free option (as of October 2026) | Free plan: 500 actions and 100 data credits a month, 200 rows per table | Free plan, no credit card needed |
Own database or many providers
This is the real split. Apollo's selling point is its own data: its home page promises 240M+ contacts and 30M+ accounts, refreshed over time, with waterfall enrichment to fill gaps. Its about page says it was founded in 2015 and uses a community-based approach to crowdsourcing data. Clay works the other way round. Its plans page says you can buy data from 200+ providers in one place and run multi-provider waterfalls, so if one source has no phone number for a contact, the next one is tried.
So Apollo answers the question where do I find leads, while Clay answers how do I combine every source I've got into the cleanest possible list.
What Apollo includes
Apollo describes three layers: data, intelligence and execution. You get a workspace for prospecting, outreach and dialling, Apollo Anywhere to work from your CRM, ChatGPT, Claude, Gmail or browser, 200+ integrations and buying signals such as intent, job changes and website visits. Its AI agents research accounts, build lists, write outreach, follow up and book meetings, prompting you at the key moments. Plans run from Free for founders and light use, through Basic for individual sellers doing regular outbound and Professional for full-time reps, to Custom for larger teams.
What Clay is built for
Clay calls itself the infrastructure to get any data, run agentic workflows and launch GTM plays. Its use cases include sourcing your total addressable market, enriching, scoring and routing inbound leads, personalising outbound with intent signals, keeping CRM records fresh and turning top accounts into ad audiences on LinkedIn, Meta and Google. The free plan includes unlimited seats and tables, multi-provider waterfalls and Claygent, and paid plans add phone enrichment, job-change tracking and email sending, with a 14-day trial.
Which suits your team
- Small team that needs leads and a way to email them today? Apollo does both in one place.
- Ops person who loves spreadsheets and automation? Clay gives you the building blocks.
- CRM full of gaps and stale records? Clay's waterfall enrichment is built for that.
- Want AI to book meetings for you? Apollo's agents are designed to go from goal to booked meeting.
- Running ads to target accounts? Clay can push audiences to LinkedIn, Meta and Google.
For more options, see my list of B2B lead generation tools, and before you enrich anything, run through this CRM data clean-up guide.
My advice on Clay or Apollo
If you're a founder or a small sales team, I'd start with Apollo: you get contacts, sequences and calling in one tool, and the free plan lets you test it on real prospects. Move to Clay, or add it alongside, when you've got someone who enjoys building workflows and you want to squeeze more coverage out of several data sources. Don't buy both on day one; get one outbound motion working, then add the tool that fixes its weakest step.
Want AI doing the heavy lifting in your marketing?
I build the systems that handle the boring 80 percent, so you get your week back. Done properly, with the human kept in.
Do you make sales prospecting tools? Tool makers can ask to be considered for a featured place in comparisons like this one.
Frequently asked questions
Is Clay free?
Clay has a Free plan with 500 actions and 100 data credits a month, unlimited seats and tables and up to 200 rows per table. Paid plans start with a 14-day trial.
Is Apollo free?
Yes. Apollo has a Free plan for exploring or light usage, and you can sign up without a credit card.
How big is Apollo's database?
Apollo says it has 240M+ contacts and 30M+ accounts of B2B data.
What is waterfall enrichment?
It means trying several data providers in turn to fill a missing field. Clay runs multi-provider waterfalls across 200+ providers, and Apollo also lists waterfall enrichment.
When was Apollo founded?
Apollo's about page says it was founded in 2015, with Tim Zheng as CEO and founder.
