Clay vs Seamless.AI (2026): Data, Pricing and API Compared

Clay and Seamless.AI both sell contact data, but they work differently. Clay is a table workflow that buys data from 150+ providers on credits. Seamless.AI owns a contact database, bills in credits, and publishes no dollar price. Neither publishes a price at 1M records.

Verdict

• Pick Clay if you want a visual workflow that tries several data sources per row, and you want public prices. Its Public API is on every plan, Free included (Clay docs, September 2026).
• Pick Seamless.AI if your reps want one platform with a large contact base and mobile numbers, and you are fine buying through sales. One credit covers a contact's email and phone together (Seamless.AI docs, September 2026).
• Pick neither if you pull people and company data by API at volume and want a price you can read. Clay has no public 1M price, and Seamless.AI has no dollar price at all. LeadOcean is one option, covered below.

Side by side

Figures were checked in September 2026. Both vendors change plans often, so confirm before you buy.

Data and coverage

Seamless.AI is the one with a database it can count. It claims 2.2B+ verified contacts, 1.6B+ verified business emails, 448M+ verified mobile numbers and 121M+ companies (Seamless.AI platform overview, September 2026). These are the vendor's own claims. Treat them as marketing until you run your own list.

Clay does not publish a record count. It buys data from 150+ providers and runs them as a waterfall, so the email you get depends on which provider answered (Clay pricing, September 2026). Clay also has a search over its own GTM database, capped at 500 results per request on paid plans (Clay developer docs, September 2026).

The difference is where the data comes from. Seamless.AI sells one database through one credit meter. Clay sells access to many databases, which widens the odds of a hit and multiplies the formats you handle.

Phones are the sharpest gap. Clay's Free plan has no phone enrichment, and Clay does not publish a phone credit cost (Clay pricing, September 2026). Seamless.AI folds the phone into the same credit as the email (Seamless.AI docs, September 2026).

Neither number is proof of fit. Hit rate depends on your titles, countries and company sizes. Run the same 100 contacts through both before you sign anything.

API and developer experience

Clay lets you read its docs and call its API before you pay. Seamless.AI needs a plan that includes API access, and the API page sends you to sales (Seamless.AI API page, September 2026).

Clay, run a function over one domain. The key goes in the clay-api-key header, and results come back by polling (Clay developer docs, September 2026).

curl --request POST \
  --url "https://api.clay.com/public/v0/routines/function:t_abc123/run" \
  --header "Content-Type: application/json" \
  --header "clay-api-key: $CLAY_PUBLIC_API_KEY" \
  --data '{"items":[{"id":"row-1","inputs":{"domain":"acme.com"}}]}'

The run returns a routine_run_id. You poll GET /routines/run/{id}/results until it returns HTTP 200. The function is one you build in the Clay UI, so the request is only half the work.

Seamless.AI, start a contact research job. The key goes in a Token header, and the call returns HTTP 202 with requestIds (Seamless.AI docs, September 2026).

curl -X POST https://api.seamless.ai/api/client/v1/contacts/research \
  -H "Content-Type: application/json" \
  -H "Token: $SEAMLESS_API_KEY" \
  -d '{"contacts":[{"contactName":"Jane Doe","companyName":"Acme Corp","title":"CTO"}]}'

You then poll GET /contacts/research/poll or take the result by webhook. A poll ends in done, error, missing or duplicate. The docs do not say how long a job takes.

Rate limits differ in kind. Seamless.AI publishes one: 60 requests a minute per endpoint, shared by every key and user in the organization. Search, research and poll each get their own window (Seamless.AI docs, September 2026).

Clay's Public API has a per-workspace limit and no published number. Over it you get HTTP 429 with a Retry-After header (Clay developer docs, September 2026). For the HTTP API column you set the limit yourself, for example 10 requests per second (Clay docs, September 2026).

Batch size favors Seamless.AI. One research request takes up to 500 records, while a Clay function run takes 1 to 100 items (Clay developer docs, September 2026).

On MCP, both ship a hosted server. Seamless.AI lists 57 tools that cover search, research, campaigns and email (Seamless.AI MCP docs, September 2026). Clay MCP exposes its providers, research agents and your saved functions inside Claude, ChatGPT and Codex (Clay MCP guide, September 2026).

Pricing

Clay bills a plan fee plus two meters. Seamless.AI bills credits and publishes no dollar price. Clay figures use the monthly list price first, with the billed-yearly price after it.

At 10,000 work emails a month

• Clay needs 10,000 Actions, one per enrichment. At the docs example of 0.5 credit per email find, that is 5,000 Data Credits (Clay docs, September 2026).
• On Launch, the 15,000 Action tier is $60 and the 6,000 credit tier is $290. That is $60 + $290 = $350 a month billed monthly. Yearly billing is 10 percent off, about $315 (Clay pricing, September 2026).
• Seamless.AI needs 10,000 credits at 1 credit per contact researched. That equals one Pro license's monthly allowance. If each record first comes from a search at 1 credit per 10 results, add 1,000 credits, so 11,000 (Seamless.AI docs, September 2026).
• Seamless.AI dollar price: Not published. Pricing is a quote form (Seamless.AI pricing, September 2026).

A full profile costs Clay more. Clay says a fully enriched record typically costs 6 to 20 Data Credits (Clay docs, September 2026). At 6 credits, 10,000 records need 60,000 credits, above the 50,000 a month top public tier.

At 1M work emails a month

• Clay: No public 1M price. A run needs 1,000,000 Actions, and the largest public Action tier is 200,000 a month. Actions cannot be bought as top-ups. Above that, Clay sells Enterprise by quote (Clay pricing, September 2026).
• For scale, the largest public Growth combination is 200,000 Actions at $850 plus 50,000 credits at $2,125. That is $2,975 a month billed monthly, or $2,678 billed yearly. It covers a fifth of the Actions.
• Seamless.AI: No public 1M price. 1,000,000 contact researches need 1,000,000 credits, or 1,100,000 with a search first. A Pro license carries 10,000 credits a month, so that is 100 licenses or a bulk pool. Both are quote only (Seamless.AI credit docs, September 2026).
• Seamless.AI speed: at 500 records a call and 60 calls a minute, 1M records is 2,000 research calls, about 34 minutes of request windows. Job completion time is not documented (Seamless.AI docs, September 2026).

We do not multiply a rate out to 1M for either tool. A number built that way is arithmetic past the public tiers, not a price anyone will quote you.

Contract terms differ too. Seamless.AI subscriptions are annual, sales are final, and cancelling needs 60 days' notice before renewal or it renews for 12 months (Seamless.AI terms, September 2026). Clay lists monthly billing on Launch and Growth (Clay pricing, September 2026).

Where Clay wins

• Public prices. You can cost a plan before you talk to anyone.
• A Public API and CLI on every plan, so a developer can test before buying a seat.
• A visual table workflow. Ops people add columns, conditions and waterfalls without code.
• Choice of sources. It runs 150+ providers per row, and your own provider keys skip Data Credits so you pay only Actions (Clay pricing, September 2026).
• A no-result enrichment costs nothing. Clay charges no Data Credits or Actions when a lookup comes back empty.

Where Seamless.AI wins

• One database you can count against. It claims 2.2B+ contacts and 448M+ mobile numbers, against Clay's unpublished count.
• One credit per contact covers email and phone together, so a record has one price.
• A published rate limit and a clear batch size: 60 requests a minute, 500 records per research request.
• A sales platform around the data. Its MCP server covers campaigns, email and call logging, not only lookups (Seamless.AI MCP docs, September 2026).
• A Free license with 50 credits, so a rep can try the data without a quote.

If you need volume through an API

LeadOcean is a data API and MCP server with no credits, no per-record price and no CRM in front of it. Pro costs $499 a month flat, and the Free plan gives 1,000 records one-off with no card (LeadOcean pricing, September 2026). Both plans get the same REST API and 12-tool MCP server, and POST /v1/exports returns up to 50,000 rows per request (LeadOcean exports docs, September 2026). It has an export app, not a table workflow builder or a sales suite, and its 693M people are far fewer than Seamless.AI claims. Compare on a list you know. See pricing or the Clay alternative.

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