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

FullEnrich is the one to pick if you want a public price and an API-first tool. Seamless.AI is the one to pick if reps need a sales app and you can work through a quote. At 1M records a month neither publishes a price.

Verdict

• Pick Seamless.AI if reps will live in the product. It has a Chrome extension, a dialer and a claimed 2.2B+ verified contacts and 448M+ mobile numbers (Seamless.AI, September 2026). You accept an annual contract and a sales quote.
• Pick FullEnrich if developers or RevOps call an API and want to see the price first. Credits are public, you pay only for what is found, and the API and MCP server are on every plan (FullEnrich pricing, September 2026).
• Pick neither if you need 1M records a month at a fixed bill. Neither tool publishes a 1M price. LeadOcean Pro is $499 a month flat over REST and MCP, which fits that job, but it is not a sales app.

Side by side

All figures checked in September 2026. Both vendors change plans, so confirm before you buy.

Data and coverage

Seamless.AI claims the bigger database, but the two numbers measure different things. Seamless.AI says 2.2B+ verified contacts and 121M+ companies. FullEnrich lists 800M people and 50M companies for search (FullEnrich pricing, September 2026).

FullEnrich's homepage also shows 1.6B contacts. That is a customer quote about coverage, not FullEnrich's own database size, so ignore it when comparing.

The two tools build coverage differently. Seamless.AI holds its own claimed dataset. FullEnrich asks 25+ sources in turn for each person, so a miss at one source can be a hit at the next (FullEnrich pricing, September 2026).

On phones, Seamless.AI gives a number to compare: 448M+ verified mobiles. FullEnrich publishes none. It does say about 30% of raw data is removed by verification, which cuts volume but should cut bounces.

Neither claim is ours to confirm. We did not test find rates, and a bigger database does not mean a higher hit rate on your list. A claim of 2.2B contacts says little about how many of your 5,000 target accounts it covers.

Run the same 100 contacts through both before you commit. Count how many return an email, how many return a mobile and how many emails bounce. That test costs a few credits and settles the question better than any vendor figure.

API and developer experience

Both APIs are asynchronous, so neither returns a contact in one call. They differ in what you send and how you collect the result.

Seamless.AI researches by search result ID, by name and company, by email or by LinkedIn URL. One request takes up to 500 records and returns request IDs. You poll GET /contacts/research/poll for the result (Seamless.AI docs, September 2026).

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

FullEnrich takes a LinkedIn URL, or a name plus a domain or company. You choose the fields to enrich, up to 100 contacts per call. The response is an enrichment ID, and a webhook is the recommended way to get results (FullEnrich docs, September 2026).

curl -X POST "https://app.fullenrich.com/api/v2/contact/enrich/bulk" \
  -H "Authorization: Bearer $FULLENRICH_API_KEY" \
  -H "content-type: application/json" \
  -d '{"name":"Acme leads","data":[{"first_name":"Jane","last_name":"Doe","domain":"acme.com","enrich_fields":["contact.work_emails"]}]}'

Throughput is the practical difference. Seamless.AI takes 500 records a request at 60 requests a minute, so 1M records is 2,000 research calls, about 34 minutes of request windows. FullEnrich takes 100 contacts a request at 60 calls a minute, so 1,000,000 / 6,000 a minute is about 167 minutes (Seamless.AI docs; FullEnrich docs).

Those are request windows only. Seamless.AI does not document how long an asynchronous 1M job takes to finish.

On MCP, Seamless.AI runs a hosted server with 57 tools. Search tools use no credits and research tools do (Seamless.AI MCP docs, September 2026). FullEnrich includes its MCP server on every plan, even the free trial (FullEnrich pricing, September 2026).

Pricing

FullEnrich is the only one of the two with prices you can read. Seamless.AI publishes credits but no dollars.

FullEnrich credits

A work email is 1 credit, a personal email 3 and a mobile 10. A lookup that finds nothing costs 0 (FullEnrich docs, September 2026). Monthly list prices run from $29 for 500 credits to $3,500 for 100,000 credits, which is $0.035 a credit (FullEnrich pricing, September 2026).

Seamless.AI credits

One credit researches one contact, and it covers the email and phone together. Search costs 1 credit per 10 results returned. A Pro license carries 10,000 credits a month (Seamless.AI docs, September 2026). Seamless.AI states no dollar price for any license (Seamless.AI pricing, September 2026). Subscriptions are annual, and cancelling needs 60 days' notice before renewal (Seamless.AI terms, September 2026).

Worked example

For FullEnrich at 10,000, the 10,000-credit tier is $499 monthly. The yearly option is 120,000 credits for $454 a month (FullEnrich pricing, September 2026). You spend less if some lookups find nothing. Add mobiles and a found contact costs 11 credits, so 10,000 of them is up to 110,000 credits, above the top monthly tier.

At 1M, FullEnrich has no public price. The top monthly tier covers 100,000 credits, a tenth of the volume, and above that the page says contact sales (FullEnrich pricing, September 2026). We do not multiply its rate out to 1M.

For Seamless.AI at 1M, searching first adds 100,000 credits, so 1,100,000 in all. That is 100 Pro licenses or a bulk credit pool. Both are quote only (Seamless.AI bulk credits, September 2026). We will not multiply a rate out, because none is published.

Where Seamless.AI wins

A sales app, not only an API. Seamless.AI ships a Chrome extension, a dialer and emailing (Seamless.AI, September 2026). FullEnrich lists no dialer or Chrome extension on its pricing page.

One credit for email and phone. A contact researched through Seamless.AI costs 1 credit and returns both. At FullEnrich, the same contact with a work email and a mobile is up to 11 credits.

The bigger claimed database. 2.2B+ verified contacts and 448M+ mobile numbers is a larger claim than 800M people. If your list is broad and you want mobiles at scale, test Seamless.AI.

Where FullEnrich wins

A price you can read. Pro starts at $29 a month and every tier is public up to 100,000 credits. Seamless.AI makes you fill in a form.

Pay only for found data. A miss costs 0 credits, and a landline found instead of a mobile is free (FullEnrich pricing, September 2026). Credits roll over 3 months on monthly plans and 12 on annual.

Waterfall mobile coverage and no seat fees. Asking 25+ sources suits mobile numbers, where one dataset has gaps. Users are unlimited on every plan, and API and MCP are included from the free trial.

If you need volume through an API

Neither tool publishes a price at 1M records a month. LeadOcean has two plans: Free, with 1,000 records one-off and no card, and Pro at $499 a month flat. There are no credits and no per-record price.

The API runs at 100 requests per second per key on every plan, and one call returns a profile and email status. The MCP server at https://api.leadocean.io/mcp has 12 tools. POST /v1/exports returns up to 50,000 rows a request, so 1M rows is about two days at the daily export limit. LeadOcean has 693M people, a smaller database than either vendor lists, and it has no dialer or Chrome extension.

Read the full numbers on pricing, or see LeadOcean as a Seamless.AI alternative.

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