Sluice vs Warmly

This is not a close comparison

Most comparison pages find a way to call it even. This one should not. Website visitor identification is Warmly's whole product. For Sluice it is one source among sixteen, and a deliberately limited one.

If you came here because you want to know who is on your website, the honest answer is that Warmly will tell you a great deal more than Sluice will. The rest of this page explains why, what the gap costs, and the narrower case where Sluice's approach is enough.

How does Sluice identify visitors?

You add a one-line snippet to your site. When someone visits, Sluice looks up who owns the IP range the visit came from, using public registry data. If that range belongs to a company, the company appears with the pages it read.

That is all. No cookie is set, no IP address is stored, and nothing about the individual is inferred. It is a form of reverse IP lookup restricted to ownership records.

The consequence is coverage. Organisations that own their network show up: larger companies, universities, public bodies. A ten-person agency on a shared business broadband line looks the same as a home connection and is invisible. So is anyone on mobile data or working from home. Sluice does not guess at those visitors.

For a small business selling to other small businesses, that may mean most of your visitors never appear. That is a real limit and you should weigh it before relying on the source.

What does Warmly do that Sluice does not?

Based on its pricing page, the entry plan at $10,000 a year includes:

• Identification of contacts as well as companies.
• Filtering visitors against your ideal customer profile.
• Real-time alerts, including Slack.
• Lead routing and CRM sync, plus webhooks.
• Retargeting by email, LinkedIn and ads.

Inbound Chat ($20,000 a year) adds an AI chatbot and live chat. AI Inbound Autopilot ($30,000 a year) adds autonomous agents for qualification and follow-up. A GTM Signals add-on ($10,000 a year) brings intent, hiring and funding data.

Sluice does none of the alerting, routing, chat or person-level identification. It also does not push visitor alerts to Slack or a CRM in real time; the companies it identifies simply appear in Sluice with the pages they read, for you to look at when you choose. If speed to a live visitor is the point, that difference alone decides it.

Working out whether $10,000 a year pays

A simple test before buying any visitor tool:

1. Count monthly visitors from companies, not total sessions. A reverse IP report on a month of traffic gives a rough figure.
2. Estimate how many of those companies fit your customer. If you sell to finance teams at mid-size firms, a university visit does not count.
3. Ask how many a week your team could genuinely follow up within a day.
4. Multiply that by your close rate and deal size, then compare with the annual price.

Say you get 300 identifiable company visits a month, 30 fit, your team works 20, and 1 in 20 becomes a $15,000 customer. That is one deal a month, and Warmly pays for itself many times over. If you get 30 identifiable visits a month and 3 fit, it probably does not, and the money is better spent finding people elsewhere.

Where Sluice's narrower approach is enough

• You sell to larger organisations. They are the ones that own their networks, so the coverage gap matters less.
• Visitors are a supplement, not the pipeline. Sluice's main sources are elsewhere: people who engaged with posts, competitors' reviewers, Google advertisers, companies hiring, local listings and the directory. "People there" turns any visiting company into a search for the people who decide.
• Privacy matters to you. No cookie and no stored IP is a simpler position to explain.
• Budget. Sluice plans start at $9 a month with no annual contract.

More on the trade-offs in identifying website visitors without cookies and our website visitors source page.

The decision

If your website is where your buyers show up and you can act on them fast, buy Warmly; Sluice is not a substitute. If you mainly need to find buyers who have not visited yet, and want to see which larger companies did, look at what Sluice costs and treat the visitor list as a bonus.