# LeadSonar

> B2B lead data: find, verify and enrich contacts with waterfall enrichment across multiple providers, so you get email and phone coverage a single source cannot reach.

LeadSonar is a B2B lead database and enrichment platform. It finds contacts, verifies their email addresses, and enriches records with email and phone data using waterfall enrichment: rather than relying on one provider, it queries sources in sequence until a record is filled, which lifts coverage well above what any single vendor returns. Sonya, the built-in AI agent, turns a plain-language description of an ideal customer into a filtered list.

## Comparisons

- [All comparisons](https://leadsonar.io/alternative.md): Index of every vendor comparison.
- [Best B2B enrichment tools](https://leadsonar.io/alternative/best-b2b-data-enrichment-tools.md): Category overview of enrichment vendors.
- [Best Apollo alternatives](https://leadsonar.io/alternative/best-apollo-alternatives.md): Alternatives to Apollo.io.
- [Best ZoomInfo alternatives](https://leadsonar.io/alternative/best-zoominfo-alternatives.md): Alternatives to ZoomInfo.
- [Best email finder tools](https://leadsonar.io/alternative/best-email-finder-tools.md): Email finding tools compared.
- [Apollo.io](https://leadsonar.io/alternative/apollo-io.md): LeadSonar compared with Apollo.io.
- [ZoomInfo](https://leadsonar.io/alternative/zoominfo.md): LeadSonar compared with ZoomInfo.
- [Clay](https://leadsonar.io/alternative/clay.md): LeadSonar compared with Clay.
- [Cognism](https://leadsonar.io/alternative/cognism.md): LeadSonar compared with Cognism.
- [Lusha](https://leadsonar.io/alternative/lusha.md): LeadSonar compared with Lusha.
- [Hunter.io](https://leadsonar.io/alternative/hunter-io.md): LeadSonar compared with Hunter.io.
- [Snov.io](https://leadsonar.io/alternative/snov-io.md): LeadSonar compared with Snov.io.
- [BetterContact](https://leadsonar.io/alternative/bettercontact.md): LeadSonar compared with BetterContact.
- [FullEnrich](https://leadsonar.io/alternative/fullenrich.md): LeadSonar compared with FullEnrich.

## Guides

- [All guides](https://leadsonar.io/blog.md): Index of every guide.
- [Build an outbound list from scratch](https://leadsonar.io/blog/how-to-build-an-outbound-list-from-scratch.md): Sourcing a list with no starting data.
- [Clean a B2B email list](https://leadsonar.io/blog/how-to-clean-a-b2b-email-list.md): List hygiene before a send.
- [Lead list building best practices](https://leadsonar.io/blog/lead-list-building-best-practices.md): How to build lists that convert.
- [B2B contact data accuracy](https://leadsonar.io/blog/b2b-contact-data-accuracy.md): Why vendor data disagrees and what to trust.
- [Improve cold email deliverability](https://leadsonar.io/blog/how-to-improve-cold-email-deliverability.md): Getting outbound mail to the inbox.

## Company

- [About](https://leadsonar.io/about.md): Who operates LeadSonar and what it does.
- [Contact](https://leadsonar.io/contact.md): How to reach support and sales.
- [Pricing](https://leadsonar.io/pricing.md): Plans, credits and limits.
- [FAQ](https://leadsonar.io/faq.md): Common questions about data, credits and billing.
- [Press](https://leadsonar.io/press.md): Brand and press information.

## Fetching this site as markdown

- Every page has a markdown twin: append `.md` to any path (e.g. `https://leadsonar.io/pricing.md`).
- Or send `Accept: text/markdown` to any URL and the markdown representation is returned instead of HTML.
- Machine-readable summary: [agent.json](https://leadsonar.io/agent.json) (also served from `https://leadsonar.io/?mode=agent`).
- Resource catalogue: [ai-catalog.json](https://leadsonar.io/.well-known/ai-catalog.json).

Last updated: 2026-09-03