Best company search API
“Company search” is three different jobs wearing one name: lookup — a domain in, the right record out. Similar-companies search — seed companies in, ranked lookalikes out. Filter search — criteria in, a company list out. Vendors blur them; the failure modes are completely different.
Two of the three are independently benchmarked and evaluated on this site — identical inputs, public evidence, no vendor pays for rank. The third (filter search) has no independent ground truth yet, and this page says so instead of pretending.
Three jobs, one label — pick yours, then use the measured leader
| Job | In → out | Independently benchmarked? | Measured leader |
|---|---|---|---|
| Lookup | domain → company record | Yes — enrichment benchmark | Ocean.io 100.0% match rate |
| Similar-companies | seed companies → ranked lookalikes | Yes — lookalike benchmark | Parallel P@100 56.5% |
| Filter search | criteria → company list | Partially — the same providers' entity search APIs are benchmarked on similarity-shaped queries; multi-constraint criteria queries aren't in the query set yet, so vendor accuracy claims on that slice are unverified | — |
Doing prospecting rather than integration? B2B prospecting tools, split honestly →
There is no single “best” company lookalike API — this independent benchmark points to a different winner depending on how you will use the results. Pick the workflow that matches yours:
- Low volume, high accuracyPredictLeadstop 10 P@10 93.8%
Reps hand-work a handful of accounts, so the top of the list has to be right. Sharpest top-of-list precision in the benchmark.
- High volume, broad reachParallellong list P@100 56.5%
A big list runs through automated sequences, so relevance has to hold deep into the results. Best long-list precision in the benchmark.
- Market / TAM sizingParallelrelevant 1,356
You are counting the universe of similar companies, not actioning a shortlist. Returns the most relevant companies across the cohort.
- Real-time in-product featurePredictLeadsavg latency 738 ms
A live “similar companies” lookup called on page-load, where response time is the constraint. Fastest average latency in the benchmark.
Full ranking, per-seed evidence, and average latency: the lookalike benchmark →
Company search APIs — common questions
What is the best company search API in 2026?
Name the job first. For lookup — a domain in, the right company record out — Ocean.io currently has the highest measured domain match rate (100.0%). For similar-companies search — seed companies in, ranked lookalikes out — Parallel leads on long-list relevance (Precision@100 56.5%) and PredictLeads on top-of-list precision (Precision@10 93.8%). Both are independently benchmarked on identical inputs. Filter search — arbitrary criteria in, a company list out — has no independent ground truth yet; treat any 'best' claim there as a vendor claim.
What's the difference between company search, company lookup, and lookalike APIs?
Lookup answers 'what is this company?' — one identifier in, one structured record out. Similar-companies (lookalike) search answers 'what else looks like these?' — seed companies in, a ranked list out. Filter search answers 'which companies match these criteria?' — industry, size, geography, keywords in, a list out. Vendors blur all three under 'company search'; they're different products with different failure modes, and only the first two can currently be measured on identical terms.
Is there an independent benchmark for company search APIs?
For two of the three jobs, yes — on this site. Lookup is measured on the enrichment benchmark (domain match rate, field correctness, latency, cost — 300 identity-verified companies). Similar-companies search is measured on the lookalike benchmark, which exercises the providers' entity search APIs on similarity-shaped natural-language queries (identical inputs, an LLM judge scoring every returned company). Filter search is the honest gap: multi-constraint criteria queries aren't in the query set yet, so vendor accuracy claims on that slice are unverified. No vendor pays for inclusion or rank in either measured benchmark.
Which company search API is best for B2B prospecting?
For prospecting, the search job that decides list quality is picking the right accounts — the similar-companies half. Parallel currently returns the most relevant long lists on identical seeds; PredictLeads is strongest at the top of the list. The full prospecting picture — accounts, then contacts, then outreach — is split honestly on the B2B prospecting tools page.