ZoomInfo vs Seamless.AI

Reachkit makes a competing cold email tool with a built-in lead database. Neither ZoomInfo nor Seamless.AI prints a price for its main plans, so the figures here come from their own sites, help centers and terms as of October 2026, and any third-party number names its source. Seamless’s terms shut competitors out of the service, so nobody at Reachkit has an account there.

My verdict: ZoomInfo is the heavier purchase with more behind it, and Seamless.AI is the lighter one a single rep can start on. ZoomInfo sells a database it researches ahead of time, with intent topics, direct dials and enrichment that keeps a CRM current. Seamless, as the company has called itself since February 2026, looks a person up when you click, returns emails and phones for one credit, and can send sequences from your own Gmail or Outlook. Both bind you for a year.

Pick ZoomInfo if:

• Your team works from buying signals and org charts and wants them inside Salesforce, HubSpot or Dynamics.
• You want an accuracy remedy in the license and the right to keep using records once the contract ends.
• Security review matters: ZoomInfo lists SOC 2 Type II, ISO 27001 and ISO 27701.

Pick Seamless.AI if:

• One rep or a small team wants emails and phones from a single lookup, starting from a free account.
• Your reps prospect inside LinkedIn and want to send from their own inboxes in the same tool.
• Someone will own the renewal date and act 60 days before it.

Checked October 2026 on each vendor’s own pages; cells that rest on a third party name it.

ZoomInfo compiles its records ahead of time and sells access to them, while Seamless.AI says it researches each person at the moment a rep clicks Find, and each company builds its pitch on that difference.

ZoomInfo counts 500M+ contacts and 100M+ companies, built with machine learning, outside data partners and 300+ human researchers, plus 120M+ direct dials. Free users feed it too: the Lite terms let ZoomInfo access signature blocks and contacts in a connected inbox and use them to add to the database. Its data page quotes contact hit rates of 96% for emails and 87% for mobiles. The license terms go further: should over 5% of your contacts not work at the company listed, ZoomInfo must lift accuracy back to 95% within 30 days, or you may terminate and get the unused part of your fee back.

Seamless’s homepage says it’s a search engine working in real time rather than a database, and that companies like ZoomInfo keep data in databases that “can quickly get stale”. Its own pages still print totals that don’t match: 1.8B+ verified emails and 414M+ phone numbers on the homepage, 1.3B+ verified contacts on the bulk credits page. Each email comes back tagged Valid, Accept All, Unknown, Invalid or Do Not Mail, with a confidence score, and Credit Back Protection refunds the credit automatically when Seamless’s check finds an address invalid. The terms still disclaim any warranty of accuracy, and Seamless’s AI fact sheet advises trying a small batch first.

People change jobs whichever method you use. I’d judge both on a few hundred contacts from my own market and count the bounces.

ZoomInfo and Seamless.AI both sell by quote on annual terms; they differ in how you get out and what you keep.

ZoomInfo. The pricing page names Professional, Copilot Advanced and Copilot Enterprise for sales, plus three marketing plans, behind a “Get Pricing” form. Your quote depends on seat count (ZoomInfo sets a minimum it doesn’t state), credits, add-ons such as intent, integrations and term. Across 1,577 purchases, Vendr reports a $33,500 median, with deals from $7,240 to $156,042 (February 2026). Rival guides often claim ZoomInfo starts at $15,000, which its FAQ denies. ZoomInfo’s own guide says monthly billing isn’t standard, most plans are paid upfront for the year, and renewals can cost more. The license makes the agreement impossible to cancel mid-term, and your order sets the notice window for stopping a renewal: Vendr calls 30 to 90 days typical, and several guides say 60.

Seamless.AI. Its pricing URL now leads to a demo form. Lindy (January 2026) and UpLead (October 2026) report Basic at about $147 a month billed yearly, with 3,000 credits a year (250 a month in Seamless’s help center); Pro and Enterprise are quoted. Under the terms, “all sales are final” and every subscription is annual, even when billed monthly. Ending a renewal takes two steps, a modification form in the platform and a meeting with your Customer Success Representative, and both must happen 60 or more days before the renewal date. Miss that and another 12 months begin. Seamless can change prices “immediately upon notice”, adds 2% to late payments and may use collections.

What you keep. ZoomInfo lets you go on using records you obtained during the term. Seamless wants its data destroyed when you leave, with proof within 5 days if it asks. Neither suits list building for clients: ZoomInfo limits use to the licensee’s own business, with $2.00 per contact in damages for use on another’s behalf, and Seamless bars passing its data to third parties for anything of value.

Seamless.AI can run a cold email sequence itself, while ZoomInfo leaves sending to an add-on or a separate tool, and neither sets up inboxes or warms them.

Seamless.AI. The archived pricing page showed Connect on every plan, tagged as a “Limited Time” offer. Connect sends through the Gmail and Outlook accounts you link, with no limit on how many, and rotates sends between them. Out of the box an inbox has no daily cap; Seamless suggests keeping each one at 250 a day or less, and the ceiling is 1,000. There’s no warmup built in; Seamless points to “a Reputable Warm-Up Service”. One rule ties sending to the data: a bounce after sending earns credits back only on bought credits, only for mail sent through Connect, and only for the email part of the charge.

ZoomInfo. On Professional you get AI-written emails and a dialer. Copilot Advanced adds automated outreach workflows and exports emails to Outreach or Salesloft. Sequences themselves come in Engage, which ZoomInfo’s pricing guide sells as an add-on, and the site’s sales automation menu now leads to its Salesloft partnership. Nowhere on ZoomInfo’s site did I find inbox setup or warmup.

I’d set a Connect inbox far below 250 a day before trusting it with a cold list.

Seamless.AI is built for grabbing a contact from whatever page a rep has open, and ZoomInfo for keeping a company’s CRM full and current.

ZoomInfo’s Chrome extension reveals contacts while you browse. Enrichment runs in real time when CRM records are created or updated, or in scheduled batches, with controls over which fields get overwritten. It connects to Salesforce, HubSpot, Microsoft Dynamics, Marketo, Pardot and Eloqua, and Copilot Advanced adds buyer intent and website visitors.

Seamless’s extension works on LinkedIn and company websites. One click on Find costs a credit; from there a contact can be saved to a list, downloaded, synced to the CRM or dropped into Connect. Its knowledge base walks through Salesforce, HubSpot, Dynamics, Pipedrive and Zoho, the Outreach and Salesloft sequencers, and the recruiting systems Bullhorn and Greenhouse. Admins can cap each user’s draw on a shared credit pool, and calls in Connect need a Twilio subscription.

ZoomInfo sells its developer access as a separate pay-as-you-go service, GTM.AI, while Seamless.AI puts its API on every plan and charges a fraction of a credit for each AI action. Both run an MCP server, which lets Claude or ChatGPT search their contact records and pull people into a chat without opening the app.

ZoomInfo. Reps get AI agents in GTM Workspace, ZoomInfo’s seller app since October 2025, that research accounts, prepare meetings and rank deals. GTM Studio lets RevOps describe a waterfall in plain words and pulls from 25+ sources, and Agent Teams (October 2026) runs several agents on a play with approval steps. GTM.AI starts with 1,000 free data credits and 1,000 AI credits, then charges from $20 with no contract or seat fees: $0.45 down to $0.25 a record by purchase size, $0.05 per AI credit, and nothing for search or lookups. ZoomInfo notes that older subscriptions carrying only monthly credits can’t use MCP.

Seamless.AI. Each AI Assistant exchange costs 0.2 credits, as does each message from AI Prompts and AI Campaigns, announced in June 2026. Autopilot builds lists at 1 credit per contact. The API went public in May 2025 and reached every plan, free included, in May 2026, at 60 requests a minute. Connecting Claude or ChatGPT over MCP can spend credits. Seamless data also sits behind HubSpot’s Breeze Prospecting Agent, and there’s a node for n8n. Its homepage advertises “AI Agents” for six teams, and I found no help-center documentation for them.

Neither company prices its main plans in public, so this table holds what can be checked: ZoomInfo’s one published price list, GTM.AI data credits, and what reviewers report for Seamless. Neither sells inboxes, so neither column includes inboxes or warmup.

How I got there, from the GTM.AI and Reachkit pricing pages: roughly 4,000 emails a month for the founder and 25,000 for the agency, one credit per new contact, GTM.AI’s list rate for a single month’s purchase ($0.41 a record at 1,500, $0.38 at 10,000; its 70% off a first purchase isn’t counted), and Reachkit at $5 per inbox a month, $15 per domain a year (5 domains, then 20) and $25 per 1,000 extra credits.

The caveats matter more than the totals. GTM.AI isn’t what seat buyers pay: the app, phones and intent come on a contract, where Vendr’s median is $33,500 a year. A full year of credits bought up front costs less per record (18,000 for $5,760), but past 100,000 credits GTM.AI sends you to sales, and its page gives two answers on whether credits lapse after a year. For Seamless, UpLead’s Pro range assumes 5+ users, the help center gives Pro 10,000 credits a month where an archived FAQ said 10,000 a year, and Amplemarket estimates $44,000 to $90,000 a year for 25 users. Each Seamless credit includes phones, and Connect needs a warmup service on top. On Reachkit, the founder fills Growth’s 5,000 stored contacts around the fourth month, and the agency fills Scale’s 25,000 in about 2.5 months; after that, clear finished leads or move up a tier.

Both tools score well on G2 and badly on Trustpilot. G2’s reviewers are mostly product users; Trustpilot’s include many people in billing disputes or listed in the data, alongside complaints about the data itself.

ZoomInfo (October 2026): G2 lists it as GTM Workspace, at 4.5 across 9,100+ reviews. Capterra has it at 4.1 (322 reviews), TrustRadius at 8.2 out of 10 (1,887) and Trustpilot at 1.8 (343). On G2, reviewers like the contact data and find it easy to use. Trustpilot’s summary of recent reviews leads with stale and wrong contact details, and renewals recur: one 2025 reviewer cancelled “five days past the notification date” and was still held to the contract. Aggressive sales outreach and people who found themselves in the database fill out the complaints.

Seamless.AI (October 2026): G2 gives it 4.4 across 5,300+ reviews, Capterra 4.5 across 580+, and Trustpilot 1.2 across 311. G2’s summary says users like how easy it is and how accurate the contacts are. On Trustpilot, renewals dominate: one reviewer wrote in October 2026 that declining another year “shouldn’t require an appointment”. Capterra’s themes are split too: of 42 reviews that mention contracts and billing, 62% are negative, and of 71 that discuss data accuracy, 45% are, mostly over outdated or missing emails and phone numbers.

This is our product. If you’re weighing ZoomInfo against Seamless.AI to fill cold email campaigns, Reachkit puts the leads and the sending in one tool on a monthly plan.

• Leads. Lead Finder covers 500M+ people and 70M+ companies, filtered by role, seniority, industry, headcount and tech stack, and a search costs nothing. You pay 1 credit for a lead whose email verifies, with automatic refunds for leads that turn up no verifiable address.
• Campaigns. The AI drafts a sequence and sizes an audience from a one-sentence brief.
• Inboxes. Order domains at $15 a year and Google Workspace or Microsoft 365 inboxes at $5 a month, and Reachkit configures them, connects them and starts AI warmup. Bringing your own inboxes adds no per-inbox fee. New inboxes start at 3 emails a day and climb to 20, and a campaign pauses at a 5% bounce rate.
• Terms. Growth is $39 a month per workspace with 1,000 credits and unlimited teammates. You can cancel anytime and keep access to the end of the period; fees aren’t refunded.

Reachkit doesn’t do phones: no numbers, no dialer, no browser extension, and no intent data, org charts or Salesforce sync either, so a calling team should stay with ZoomInfo or Seamless. More in ZoomInfo alternatives and Seamless.AI alternatives.

Moving between ZoomInfo and Seamless.AI turns on two dates and one asymmetry: ZoomInfo lets you keep its data after you leave, and Seamless doesn’t.

• Seamless to ZoomInfo. Seamless’s terms say to destroy “any and all” of its data on exit, so plan to source those contacts again. File the request and book the meeting at least 60 days before renewal.
• ZoomInfo to Seamless. Records you obtained during the term stay usable for your own business. The contract can’t be cancelled mid-term, so find the notice date in your order first.
• CRM. Salesforce, HubSpot and Dynamics work with both, so the deal records you built don’t move when the data vendor does.
• Sequences and inboxes. Connect sends from your own Gmail or Outlook, so those inboxes keep their history wherever you go next. Sequences in Outreach, Salesloft or Engage stay in that tool.

Before the notice date, I’d test the other side on a sample: ZoomInfo’s free GTM.AI credits or Lite, or Seamless’s 50 free credits.

I’d pick by team size and by what happens after the lookup. A big team that calls, works from intent signals and buys through procurement gets more from ZoomInfo, and its accuracy clause and data-retention terms are worth having. A rep or small team that wants phones and emails from LinkedIn at a lower entry price will find Seamless quicker to start, as long as someone owns the renewal date. Either way, measure bounces on your own niche before signing. If cold email is the real job, try Reachkit for 30 days.

Related: Apollo vs ZoomInfo, Apollo vs Seamless.AI, the ZoomInfo profile and the Seamless.AI profile.