Seamless.AI and CloseFast (closefa.st) are often compared because both help agencies find clients, but they solve fundamentally different problems. Seamless.AI is a real-time B2B contact database with 1.3 billion-plus contact records — it finds email addresses and phone numbers for named individuals at companies. CloseFast is a local-business prospecting pipeline that audits marketing gaps (missing websites, absent tracking pixels, ad spend without conversion data) and generates a personalized pitch for each prospect. The pricing models diverge sharply: Seamless.AI uses opaque credit-based pricing starting around $147 per user per month with a 50-credit free sample that never refreshes, while CloseFast charges a flat €49–99 per month with no consumable credits. For an agency prospecting local businesses, CloseFast finds who needs help and why; Seamless.AI finds who to call once you already know the target.
What Each Tool Actually Does
Seamless.AI — a real-time B2B contact search engine
Seamless.AI positions itself as a real-time search engine for B2B contact data rather than a static database. It uses AI to crawl, verify, and assemble email addresses and cell phone numbers for decision-makers at target companies. The platform claims 1.3 billion-plus contacts across 150 million companies, and includes a "Connect" layer for emailing, calling, and task management inside the tool.
The core workflow is: search for a company or role, reveal contact details (1 credit = 1 contact with email + phone), export, and use those contacts in your outreach sequence. Seamless.AI also offers buyer intent data, job-change alerts, and an AI assistant for outreach writing — but most of these are paid add-ons on top of the base plan.
CloseFast — a prospect-discovery and audit pipeline
CloseFast takes a different approach. Instead of finding contact details for people you already know you want to reach, it finds the businesses themselves — local companies with visible marketing gaps. For each prospect, CloseFast runs a full audit: does the business have a website, does it have a Meta Pixel or Google Ads tag installed, is it running Facebook or Google ads, how complete is its Google Business Profile, and does it rank for its own name.
Each prospect is then ranked into A/B/C/D segments based on how urgently they need help. A business running ads with no conversion tracking is an A-tier prospect — it has budget and recognizes the need for marketing, but is spending blind. CloseFast generates a personalized pitch for each prospect based on the specific audit findings, so the agency can reach out with a concrete observation rather than a generic cold email.
Pricing Comparison
| Feature | Seamless.AI | CloseFast |
|---|---|---|
| Free tier | 50 lifetime credits (never refresh) | 10 leads/month (renews monthly) |
| Starting paid price | ~$147/user/month (annual, via third-party sources) | €49/month flat |
| Pro tier | ~$147–299/user/month (sales-quote, 5-user minimum reported) | €99/month flat |
| Pricing model | Credit-based + per-seat + add-ons | Flat monthly fee, no credits |
| Add-on costs | Buyer intent $79–199/user/month, data enrichment, autopilot | None — all features included |
| Published pricing | No — contact sales for all paid tiers | Yes — transparent on homepage |
Seamless.AI's pricing page does not publish dollar amounts for any paid tier. The Free plan shows 50 credits; Pro shows "Annual Credit Packages" with a "Contact sales" button; Enterprise shows "Custom Packages" with the same. The $147/user/month figure comes from third-party pricing aggregators (ToolRadar, CostBench, AmpleMarket) cross-verified in August 2026 — Seamless.AI does not confirm it on their own page.
Seamless.AI's Pro plan requires contacting sales for pricing, with third-party sources reporting costs of $147 to $299 per user per month depending on negotiation. A reported 5-user minimum on Pro means the floor is roughly $735 to $1,495 per month even if only two or three people actively use it. Add-ons like buyer intent data add $79 to $199 per user per month on top. (Verified August 2026 via ToolRadar, CostBench, and AmpleMarket.)
CloseFast publishes its pricing on the homepage: Free (€0, 10 leads/month), Starter (€49/month, ~250 leads), Pro (€99/month, ~600 leads). No per-seat charges, no consumable credits, no add-on costs. The price does not change based on how many searches you run within your tier's monthly lead allotment.
Data Quality and Accuracy
Seamless.AI's real-time search approach is a double-edged sword. It can surface contacts at companies too small or too new for traditional databases, but the accuracy variance is a documented problem. Third-party reviews consistently report a 20–30 percent data inaccuracy rate — meaning roughly one in four credits may be spent on outdated or incorrect contact information. The G2 rating is 4.4 out of 5 across 5,277-plus reviews, but the Trustpilot rating sits at 1.4 out of 5, reflecting a sharp divide between satisfied power users and frustrated buyers who hit credit expiry and contract auto-renewal issues.
CloseFast does not sell contact data. It audits publicly visible business signals — website presence, pixel installation, ad activity, Google Business Profile completeness — so accuracy depends on what is publicly visible, not on a contact database that may decay. The tradeoff is that CloseFast will not give you a decision-maker's direct email; it identifies which businesses to approach and why they need help.
When Seamless.AI Is the Better Choice
Seamless.AI is the right tool when you already know which companies you want to target and need to find the right person and their contact details. If your agency runs account-based outreach — you have a list of 50 target accounts and need email addresses and phone numbers for each VP of Marketing — Seamless.AI does that job well. Its real-time search can surface contacts at companies that traditional databases miss, and the Connect layer lets you call and email from within the platform.
For sales teams doing high-volume B2B outbound to named accounts, the credit model makes sense: you pay per contact revealed, and the database depth covers most industries. The buyer intent and job-change features add a timing layer that helps you reach prospects when they are most likely to buy.
When CloseFast Is the Better Choice
CloseFast is the right tool when you do not yet know which businesses to target and need to identify prospects based on their marketing gaps. If your agency sells marketing services to local businesses — plumbers, dentists, restaurants, law firms — the first question is not "who is the VP of Marketing" but "which of the 200 plumbers in my city is spending on ads without tracking, has no website, or has an incomplete Google Business Profile?"
CloseFast answers that question, ranks the results, and writes the pitch. You then use a contact-finding tool (Seamless.AI, Apollo, Hunter, or even manual lookup) to find the right person to send it to. The two tools are sequential, not competitive — CloseFast is the layer before the contact finder. For a full comparison of the lead-generation landscape, see our roundup of the best lead generation tools for marketing agencies.
The Credit Anxiety Problem
The credit-based pricing model is the most common complaint about Seamless.AI across review sites. Credits expire at the end of your contract term — overestimate your monthly need and the unused credits are wasted. A 20–30 percent inaccuracy rate means a portion of every credit purchase produces unusable data. The autopilot feature, which prospects automatically in the background, can exhaust daily credits before reps manually search if not carefully configured.
This is the same credit-anxiety pattern we documented in our comparison of CloseFast vs Clay: tools that charge per lookup create a budgeting tension where every search carries a micro-cost decision. CloseFast's flat-fee model eliminates that tension — you run as many searches as your monthly lead allotment allows, with no per-lookup deduction.
Who Should Use Which
| Your situation | Better fit |
|---|---|
| You know target accounts, need contact details | Seamless.AI |
| You need to discover which local businesses to prospect | CloseFast |
| You want person-level email and phone data | Seamless.AI |
| You want business-level audit data (ads, pixels, website) | CloseFast |
| You have a sales team doing ABM outbound | Seamless.AI |
| You are an agency finding local business clients | CloseFast |
| You want transparent, published pricing | CloseFast |
| You need a database of 1.3B+ B2B contacts | Seamless.AI |
| You want a generated pitch for each prospect | CloseFast |
For agencies that do both — find local prospects and run outbound to named accounts — the typical stack is CloseFast for discovery and qualification, then a contact finder (Seamless.AI, Apollo, or Hunter) for the actual contact details. The tools complement each other; the friction comes when one tool tries to do both jobs.
The Bottom Line
Seamless.AI is a capable B2B contact database with real-time search and deep coverage, but its opaque pricing, credit expiry, and per-seat model make it expensive for small agencies that just need to find local business clients. CloseFast costs €49–99 per month flat, finds businesses with marketing gaps, audits them, and writes the pitch — then you use whatever contact tool you prefer to reach the decision-maker. If your agency prospects local businesses, CloseFast is the discovery layer; Seamless.AI is a contact-finding tool that comes after.