Personal email API benchmark 2026: ContactOut, FullEnrich, Nyne, SignalHire, Wiza and Apollo

ContactOut found the most personal emails of the six providers tested. It returned the known personal address for 83.3% of 498 people, ahead of Nyne at 62.2%, SignalHire at 56.8% and FullEnrich at 55.6%. Wiza returned 33.7% and Apollo 12.0%. The order changes when the lookup runs the other way. Given 504 email addresses, FullEnrich matched the right profile 92.9% of the time and ContactOut 90.5%, with Apollo last again at 23.2%.

A personal email lookup takes a person and asks for the private address they use outside work. A reverse lookup takes an email address and asks who owns it. Both tests here were graded against answers that were already known, so a result counts only when it is the right one.

The short version:

• ContactOut leads personal email finding at 83.3%, 21.1 points ahead of Nyne in second place.
• FullEnrich leads reverse lookup at 92.9%, 2.4 points ahead of ContactOut. Every other provider is below 70%.
• Apollo is last in both tests, at 12.0% for personal email and 23.2% for reverse lookup.

Which API finds the most personal emails?

ContactOut finds the most. It returned the known personal email for 415 of the 498 people in the test, which is 83.3%. Nyne was second with 310, and SignalHire third with 283.

The middle of the table is close. Nyne, SignalHire and FullEnrich sit within 6.6 points of each other, so on a list of a few hundred people the three would land near the same count. The gaps at the ends are large. ContactOut found 105 more people than Nyne, and Apollo found 60 in total, which leaves 438 people with no correct personal email.

Which API is best for reverse email lookup?

FullEnrich, by a small margin. It matched 92.9% of the 504 addresses to the right profile, against 90.5% for ContactOut. That is 468 matches against 456, a gap of 12 addresses.

Below the top two the results drop fast. SignalHire is third at 67.1%, 23.4 points behind ContactOut. Nyne, Reverse Contact and Wiza are bunched between 47.6% and 51.0%, so each of them returned the wrong profile or no profile for roughly half the addresses. Reverse Contact, the one provider that took only this test, placed fifth.

How was this benchmark measured?

Both tests used a fixed panel with known answers and graded every response against them.

• Personal email. 498 people whose personal email address was already known. A provider scored a hit only when it returned that exact address. Run on 2 October 2026.
• Reverse lookup. 504 email addresses whose owner's profile was already known. A provider scored a hit only when it returned that profile. Published on 13 October 2026.
• Every provider received the same panel, and the score is hits divided by the full panel, so a provider that returns nothing for a person is scored as a miss, not left out.
• Six providers took both tests. Reverse Contact took only the reverse lookup test.

Two limits are worth knowing before you read the numbers. First, the personal email test gives credit for one address per person. If a provider returned a different personal address that also works, it counts as a miss here. Second, a hit rate says nothing about price or speed. The methodology page explains how the separate APIbenchmarks Index scores documentation, reliability, ecosystem and access for each API.

Why do the rankings change between the two tests?

The two lookups ask different questions, and the providers are not equally good at both. The chart below puts each provider's two results side by side.

FullEnrich moves the most. It is fourth on personal email at 55.6% and first on reverse lookup at 92.9%, a swing of 37.3 points. The two are different jobs. A reverse lookup starts from an address and checks who owns it. A personal email lookup has to find an address that may not be published anywhere.

ContactOut is the most consistent. It is first or second in both tests and never below 83.3%, so it is the only provider here that is strong in both directions.

Nyne is the one provider that does worse on reverse lookup. It drops from 62.2% to 51.0%, an 11.2 point fall, while every other provider scored higher on the reverse test than on personal email.

Apollo finishes last on both. Its personal email result of 12.0% is the lowest number in either test. The index describes Apollo as sales engagement plus enrichment, and this benchmark scores only personal email and profile matching, not work email.

How do these providers compare on price and API access?

Accuracy is one input. The APIbenchmarks Index also records how each API is sold and how easy it is to start using. Three of the providers in this test are in the data enrichment index.

The two measures point in different directions. ContactOut has the best personal email result but the lowest index score of the three, mostly because its API is sold on a quoted plan and the free tier does not include it. Its accessibility score is 35. Apollo has the highest index score, 80.1, because it is easy to start with and well documented, but it returned the fewest correct personal emails. FullEnrich sits between them and charges only for successful results, so a miss costs nothing. See the full scores on the ContactOut, FullEnrich and Apollo pages, or compare two directly, for example ContactOut vs FullEnrich.

The bottom line on each provider

• ContactOut. First on personal email at 83.3% and second on reverse lookup at 90.5%. The pick when finding a private address is the job. API access goes through a quoted plan.
• FullEnrich. First on reverse lookup at 92.9%, fourth on personal email at 55.6%. Pay per successful result makes it cheap to test on your own list.
• SignalHire. Third in both tests, 56.8% and 67.1%. A steady middle option.
• Nyne. Second on personal email at 62.2%, but only 51.0% on reverse lookup.
• Reverse Contact. Reverse lookup only, 48.0%, fifth of seven.
• Wiza. 33.7% on personal email and 47.6% on reverse lookup.
• Apollo. Last in both, 12.0% and 23.2%. Use it for what it is built for, not for personal email.

How to benchmark contact data providers yourself

These results come from one panel of people and one set of addresses. Your contacts may skew toward a region, an industry or a seniority level where the order is different. Take a few hundred contacts from your own CRM where you already know the personal email or the profile, send the same list to each provider you are considering, and count only exact matches. If you need company data as well, the same approach works there, and the technographics benchmark shows how a shared answer key can be built when no single source is trusted.

FAQ

Which API finds the most personal email addresses? ContactOut. It returned the known personal email for 83.3% of 498 people, ahead of Nyne (62.2%), SignalHire (56.8%), FullEnrich (55.6%), Wiza (33.7%) and Apollo (12.0%).

What is the most accurate reverse email lookup API? FullEnrich matched 92.9% of 504 email addresses to the right profile, with ContactOut close behind at 90.5%. SignalHire was third at 67.1%.

Is ContactOut or FullEnrich better? It depends on the direction of the lookup. ContactOut is far ahead on finding personal emails, 83.3% against 55.6%. FullEnrich is slightly ahead on reverse lookup, 92.9% against 90.5%. FullEnrich has the higher APIbenchmarks Index score, 72.5 against 55, because its API is easier to access.

Is Apollo good for finding personal emails? Not in this test. Apollo returned the known personal email for 12.0% of people, the lowest result in the benchmark, and matched 23.2% of addresses in reverse lookup.

How is a hit counted in this benchmark? Each person or address in the panel had a known correct answer. A provider scores a hit only when it returns that exact personal email or that exact profile. Empty responses and different answers both count as misses.