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

Seamless.AI is the bigger claimed database with an open API and no public price. UpLead is the smaller one with a price you can read and an API locked behind a custom quote. At 1M records a month, neither publishes a number. This page compares them on data, API, MCP and cost, with the arithmetic shown.

Verdict

• Pick Seamless.AI if reps will prospect in its app and you want the largest claimed pool of emails and mobile numbers. You must take a sales quote and an annual contract (Seamless.AI, September 2026; terms of use, September 2026).
• Pick UpLead if you run small, accuracy-first lookups in its app and want to budget before you talk to anyone. Essentials is $99 a month for 170 credits. An email credit is charged only for a Valid or Accept All address (UpLead pricing, September 2026; UpLead API docs, September 2026).
• Pick neither if the job is bulk volume through an API at a fixed bill. Both meter by credit and neither lists a 1M price. LeadOcean is built for that case. See the last section.

Side by side

All figures were checked in September 2026. Both vendors change plans often, so confirm on their pages before you buy.

Data and coverage

Seamless.AI publishes the bigger numbers. It lists 2.2B+ verified contacts, 121M+ companies, 1.6B+ verified business emails and 448M+ mobile numbers. UpLead states 200M+ contacts with email addresses and 19M+ companies. All of these are vendor claims, and neither explains how it counts.

The two handle bad email in opposite ways. UpLead returns an email_status on every contact and charges a credit only for Valid or Accept All. An unmatched enrichment row is refunded, and the same record is never charged twice (UpLead API docs, September 2026). UpLead also states a 95% accuracy guarantee and refunds bounces and poor data (UpLead data page, September 2026).

Seamless.AI charges one credit per contact researched, and that one credit covers the email and phone together. The docs mark a record with no result as missing on poll, but do not say whether it is charged (Seamless.AI docs, September 2026). The Seamless.AI numbers are about reach. The UpLead promise is about accuracy per credit.

Phone is where Seamless.AI claims a clear lead: 448M+ verified mobiles against no published UpLead count. UpLead does include mobile_directdial in its person record, with no verification claim.

Filters differ too. Seamless.AI contact search takes 39 filter and modifier parameters and company search takes 23 (Seamless.AI docs, September 2026). UpLead states no filter count, and its Prospector Pro and Quick Search APIs are Professional-only.

Size is not reach. Pull 500 contacts from your own CRM that you know are good, across regions and seniority levels. Run the same list through both tools, then count emails returned, bounces and phones.

API and developer experience

Seamless.AI has the open API, and UpLead has the simple one. Seamless.AI takes a Token header and answers a research call with HTTP 202 and a request ID. You poll for the result or take it by webhook. UpLead answers in the same call, but the Enrichment, Prospector Pro and Full API Access rows are ticked only on its custom-quote Professional plan.

Seamless.AI: start a research job, from its docs. The sample uses placeholder names (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"}]}'

Next you call GET /contacts/research/poll with the returned requestIds. A poll ends in done, error, missing or duplicate. The docs give no job time for a large batch.

UpLead: a person lookup by email, from its docs (UpLead API docs, September 2026).

curl -X POST "https://api.uplead.com/v2/person-search" \
  -H "Authorization: $UPLEAD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email":"jane@acme.com"}'

It returns the person, the email_status and your remaining credits in one response. The Prospector Pro, Quick Search, Industries and Lists APIs are for Professional, Elite and Enterprise plans only. Elite and Enterprise are not on the current pricing page.

On MCP, Seamless.AI runs a hosted server at mcp.seamless.ai/mcp with 57 tools, OAuth 2.1 or an API key, and it must be enabled on the account. Search tools use no credits and research tools do (Seamless.AI MCP docs, September 2026). UpLead mentions none, so an agent that needs UpLead data goes through a third-party connector.

On limits, UpLead allows 500 requests a minute, about 8 a second. Seamless.AI allows 60 a minute per endpoint, shared across the whole organization, with separate windows for search, research and poll. Seamless.AI makes up for it with 500 records per call.

Pricing

Seamless.AI publishes credits and no dollars. UpLead publishes dollars and a per-credit rate. The examples count one contact lookup as one record.

Seamless.AI at 10,000 records a month

10,000 contact researches is 10,000 credits, at one credit per record (Seamless.AI docs, September 2026). A Pro license carries 10,000 credits a month, so that is one license. If you find the contacts by search first, add 1 credit per 10 results: 10,000 / 10 = 1,000 more. That is 11,000 in all, so a second license or a bulk pool. No dollar figure exists to calculate, because the pricing page is a quote form (Seamless.AI pricing, September 2026). Get a written quote.

Seamless.AI at 1M records a month

No public 1M price. A 1M pull is 1,000,000 credits, or 1,100,000 if each record first comes from a search. At 10,000 credits a license, that is 100 Pro licenses or a bulk pool, both quote only. In calls, 1,000,000 / 500 = 2,000 search calls and 2,000 research calls. At 60 requests a minute per endpoint, each takes about 34 minutes, in separate windows, plus polling. Async completion time is not documented. The calls are fast. The bill is a quote.

UpLead at 10,000 records a month

Plus is $199 a month with 400 credits, or $149 a month billed yearly. Extra credits cost $0.50 each on the monthly plan (UpLead pricing, September 2026).

• Plus, monthly billing: 10,000 - 400 included = 9,600 extra credits x $0.50 = $4,800, plus $199 = $4,999 a month.
• Essentials, monthly billing: 10,000 - 170 = 9,830 extra credits x $0.60 = $5,898, plus $99 = $5,997 a month.

UpLead caps extra credit purchases at $2,000 a day, so the $4,800 takes at least three days (UpLead help center, September 2026). Plus does not list API access, so this is an in-app route. The extra-credit rate on yearly billing is not printed.

UpLead at 1M records a month

No public 1M price. The highest public tier is Plus, and the daily cap decides the rest: $2,000 / $0.50 = 4,000 extra credits a day x 31 days = 124,000 extra credits. With the 400 included, that is about 124,400 credits for $62,199 in the month, an eighth of 1M. Professional is a custom quote with annual billing only, and the help center does not say whether the cap applies to it.

Where Seamless.AI wins

• The largest claimed pool. 2.2B+ contacts, 1.6B+ business emails and 448M+ mobile numbers, against 200M+ contacts at UpLead (Seamless.AI API page, September 2026).
• An API and MCP server you can reach. REST and a 57-tool hosted MCP server, with up to 500 records per research call (Seamless.AI MCP docs, September 2026).
• One credit for email and phone. A single credit covers both on a researched contact.
• A free license to test. 50 credits, no refill (Seamless.AI credit docs, September 2026).

Where UpLead wins

• A price you can read. $99, $199 or a quote. You can budget a small team before you talk to anyone.
• Pay only for usable emails. A credit is charged only for Valid or Accept All, and unmatched enrichment rows are refunded (UpLead API docs, September 2026).
• An accuracy guarantee. UpLead states 95% and refunds bounces (UpLead data page, September 2026).
• A higher request limit. 500 requests a minute, against 60 per endpoint at Seamless.AI.

If you need volume through an API

Both tools meter by credit, and neither publishes a price at 1M records a month. LeadOcean is a data API with one flat price. Pro is $499 a month with no credits, and the Free plan gives 1,000 records, one-off, with no card. You get 693M people and 63M companies over REST and a 12-tool MCP server on every plan, at 100 requests per second per key. Bulk export is POST /v1/exports at 50,000 rows per request, up to 500,000 rows a day (LeadOcean docs, September 2026).

If you are weighing other contact finders, we also compared Seamless.AI against SalesIntel, LeadIQ and Lead411. If Seamless.AI is your current tool, see the Seamless.AI alternative page and Seamless.AI alternatives compared. Plans are on the pricing page.

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