Head to head
Apollo.io vs Seamless.AI
As a data enrichment API, Apollo.io rates higher on the APIbenchmarks Index, 80.1 to 68.3, a 11.8-point gap. Here is how they compare on each criterion.
Criterion by criterion
| Criterion | Apollo.io | Seamless.AI |
|---|---|---|
| Documentation & DX | ||
| Reliability | ||
| Ecosystem & SDKs | ||
| Accessibility | ||
| APIbenchmarks Index | 80.1 | 68.3 |
Specifications
| Apollo.io | Seamless.AI | |
|---|---|---|
| Best for | Sales engagement plus enrichment | Prospecting teams wanting UI plus API and MCP |
| Free tier | 10k credits/mo (verified corporate domain) or 100/mo | Free plan (50 lifetime credits per third party; API eligibility unconfirmed) |
| Pricing | Per credit (email 1, phone 8) | Per credit; sales-led Pro/Enterprise |
| Official SDKs | 6 languages | 6 languages |
Is Apollo.io better than Seamless.AI?
On the APIbenchmarks Index, Apollo.io rates higher (80.1 vs 68.3). It leads on the four weighted criteria, but price is reported separately, so the best choice still depends on your budget.
Verdict in one line
Apollo.io leads by 11.8 points (80.1 vs 68.3) and wins 4 of 4 criteria.
Winner by criterion
| Criterion | Winner | ||
|---|---|---|---|
| Documentation & DX | 80 | 76 | |
| Reliability | 84 | 74 | |
| Ecosystem & SDKs | 78 | 68 | |
| Accessibility | 78 | 50 |
Choose Apollo.io if… / choose Seamless.AI if…
- →documentation & dx matters most to you (80 vs 76)
- →reliability matters most to you (84 vs 74)
- →ecosystem & sdks matters most to you (78 vs 68)
- →accessibility matters most to you (78 vs 50)
- →your use case matches its focus: sales engagement plus enrichment
- →your use case matches its focus: prospecting teams wanting ui plus api and mcp
Pricing side by side
- Model
- Per credit (email 1, phone 8)
- Free tier
- 10k credits/mo (verified corporate domain) or 100/mo
- Free$0
- Basic$49/user/mo (annual)
- Professional$79/user/mo (annual)
- Organization$119/user/mo (annual)
- Overage credits$0.20 / credit
- Model
- Per credit; sales-led Pro/Enterprise
- Free tier
- Free plan (50 lifetime credits per third party; API eligibility unconfirmed)
- Free$0
- ProContact sales (third-party: about $4,740-$9,000/yr for 5 users)
- EnterpriseCustom
Vendor-published pricing, verified 2026-06-27 (Apollo.io) and 2026-10-07 (Seamless.AI).
SDK and language coverage
Both · 1
REST API (HTTPS / JSON)
Only Apollo.io · 5
OpenAPI / Swagger specificationApollo MCP serverApollo CLIllms.txt index for AI agentsCommunity-built clients (e.g. Ruby gem EnaiaInc/apollo_io), no official first-party language SDKs
Only Seamless.AI · 5
OpenAPI YAML/JSONPostman collectionMCP servercurl, Python and Node examplesNo official language SDKs found
Strengths and weaknesses
- +Large database (275M+ contacts, 73M+ companies) with strong US coverage (~80–88% match accuracy)
- +Aggressive pricing that undercuts ZoomInfo/Lusha-class incumbents for comparable breadth
- +Bulk enrichment endpoints (up to 10 people or companies per call) reduce call volume
- –Data accuracy drops sharply outside the US (~60–73% in EU/APAC/LATAM); stale titles common
- –Phone numbers cost 8 credits each yet user-reported direct-dial accuracy is only ~50–70%
- –Credits expire every billing cycle with no rollover and no refund on unused balance
- +Modern async API with webhooks or polling plus OpenAPI YAML/JSON specs
- +MCP server with 57 tools documented for Claude, Cursor, VS Code and ChatGPT
- +Published rate limits and simple credit rules (search 1 credit per 10 results; polling free)
- –Plan eligibility for the API is unclear and sources conflict
- –60 requests/min per endpoint, restrictive for bulk jobs
- –Pro and Enterprise pricing is sales-led
Apollo.io vs Seamless.AI: questions
- Which has better documentation, Apollo.io or Seamless.AI?
- Apollo.io scores higher on documentation and developer experience: 80 vs 76 out of 100.
- Which is more reliable, Apollo.io or Seamless.AI?
- Apollo.io scores higher on reliability: 84 vs 74 out of 100.
- Do Apollo.io and Seamless.AI have a free tier?
- Apollo.io: yes (10k credits/mo (verified corporate domain) or 100/mo). Seamless.AI: yes (Free plan (50 lifetime credits per third party; API eligibility unconfirmed)).
- How are Apollo.io and Seamless.AI priced?
- Apollo.io: Per credit (email 1, phone 8). Seamless.AI: Per credit; sales-led Pro/Enterprise.
- Which has more official SDKs?
- Both list 6 official SDKs.