# GenderAPI.io vs NameGender.com

> Compare GenderAPI.io V2 with NameGender: current V1 routes, name/email/username inputs, confidence scales, AI defaults, nickname options, batches and billing.

Canonical HTML: https://www.genderapi.io/genderapi-io-vs-namegender-com

Last reviewed: 2026-09-26

## About this comparison

Published by GenderAPI.io, one of the providers discussed. This is a dated review of public documentation, not an independent performance test or an endorsement by another provider. We did not run competitor prediction requests. Undocumented in a reviewed reference does not mean unavailable. Recheck the linked contract and pricing before integrating.

## What changes between these APIs?

Both services document name, email and username workflows. Important differences include AI defaults, batch structure and confidence semantics. NameGender best_guess and GenderAPI.io forceToGenderize describe different behaviors and should not be mapped automatically.

| Decision point | GenderAPI.io V2 | NameGender.com | Sources |
| --- | --- | --- | --- |
| Inputs and authentication | Names, email addresses and usernames use type and value on /api/v2/gender. Authorization: Bearer with a GenderAPI.io key. Query keys are available for simple GET examples; prefer headers in applications. | Separate /api/v1/gender, /gender/email and /gender/username routes; Bearer or X-Api-Key. URL keys are rejected. | [GenderAPI.io V2 request parameters](https://www.genderapi.io/docs/v2/request-parameters); [GenderAPI.io V2 authentication](https://www.genderapi.io/docs/v2/authentication); [REST API Reference — NameGender](https://namegender.com/docs) |
| Batch requests | Up to 50 keyed items or 10 IP-trial items. Each item can have its own type, country and options. | Up to 100 values per /api/v1/gender/bulk request; one input type and country for the whole batch. | [GenderAPI.io V2 batch guide](https://www.genderapi.io/docs/v2/batch); [NameGender API: Bulk request](https://namegender.com/docs/ai/bulk.md) |
| Confidence and unknowns | data.confidence is 0–1 or null. confidence_kind distinguishes stored-count frequency from an AI score; sample_count is null for AI. data.result_status: unknown; data.gender and data.confidence are JSON null. Inspect data.reason. | probability: 0–100; confidence: a category such as high or unknown; sample_size: an integer. gender can be null. | [GenderAPI.io V2 responses](https://www.genderapi.io/docs/v2/responses); [NameGender API OpenAPI 3.1 contract, info.version 1.0.0](https://namegender.com/openapi.json) |
| AI fallback | Explicit off, fallback or always. Singles default to fallback; batches default to off. Optional forceToGenderize uses the dataset first, then nickname-aware AI. | ai_fallback defaults to false and requires account consent. The reference describes 1 extra credit when AI is used. | [GenderAPI.io V2 AI options](https://www.genderapi.io/docs/v2/ai-options); [REST API Reference — NameGender](https://namegender.com/docs) |
| Nickname options | forceToGenderize applies to all three input types and can infer an alias association even when data.name is null. | best_guess lowers the name-evidence threshold. For email/username it acts on an extracted first name. | [GenderAPI.io V2 AI options](https://www.genderapi.io/docs/v2/ai-options); [NameGender API: Gender from a name](https://namegender.com/docs/ai/name.md); [NameGender API: Gender from an email](https://namegender.com/docs/ai/email.md); [NameGender API: Gender from a username](https://namegender.com/docs/ai/username.md) |
| Unknown-result billing | Ordinary successful lookups cost 1 credit, even unknowns and fallback AI. Always-AI costs 2. forceToGenderize costs 1 for a resolved dataset result or 2 when AI runs. | An ordinary successful unknown still costs 1 credit. Read credits_charged and credits_remaining. | [GenderAPI.io V2 credits and usage](https://www.genderapi.io/docs/v2/credits-and-usage); [NameGender API: Gender from a name](https://namegender.com/docs/ai/name.md); [NameGender API OpenAPI 3.1 contract, info.version 1.0.0](https://namegender.com/openapi.json) |
| Payment models | Monthly subscriptions and one-time packages; see current plan terms. | One-time packages plus monthly/yearly subscriptions. Subscription credits reset monthly; one-time credits persist until used. | [GenderAPI.io pricing](https://www.genderapi.io/price); [Pricing — NameGender](https://namegender.com/pricing) |

## Before you switch an integration

Map the endpoint-specific name, email or username field to type and value. Rework bulk names into items, respecting the smaller V2 limit. Use meta.usage.charged_credits and remaining_credits for usage. Select options.ai_mode explicitly: NameGender’s documented AI default differs from a GenderAPI.io single request.

Dividing a NameGender probability by 100 only changes its units. It does not make it statistically equivalent to GenderAPI.io confidence. NameGender confidence is categorical; GenderAPI.io confidence is numeric and confidence_kind describes its basis. Review both your parser and thresholds.

Sources: [REST API Reference — NameGender](https://namegender.com/docs); [NameGender API OpenAPI 3.1 contract, info.version 1.0.0](https://namegender.com/openapi.json); [NameGender API: Bulk request](https://namegender.com/docs/ai/bulk.md); [GenderAPI.io V2 request parameters](https://www.genderapi.io/docs/v2/request-parameters); [GenderAPI.io V2 AI options](https://www.genderapi.io/docs/v2/ai-options); [GenderAPI.io V2 batch guide](https://www.genderapi.io/docs/v2/batch); [GenderAPI.io V2 responses](https://www.genderapi.io/docs/v2/responses); [GenderAPI.io V2 credits and usage](https://www.genderapi.io/docs/v2/credits-and-usage)

- [V2 request fields](https://www.genderapi.io/docs/v2/request-parameters)
- [V2 response fields](https://www.genderapi.io/docs/v2/responses)
- [Batch processing and item errors](https://www.genderapi.io/docs/v2/batch)

## Evaluate the workflow you will deploy

Choose a representative sample you are permitted to process and keep the original inputs, preprocessing and country context fixed. Evaluate name, email and username workflows separately. Record provider, endpoint, date, configuration and whether AI was used.

Measure coverage (answered / eligible), accuracy among answered results (correct / answered), and correct results across all eligible inputs (correct / eligible). Report unknowns, errors, costs and latency separately. A threshold should be selected on validation data and then checked on a held-out sample.

GenderAPI.io does not publish an independent reference-labelled accuracy benchmark here. Database counts, contract tests and one provider's published study cannot establish which service will work best on your data. An inferred association does not establish a person's gender identity.

Sources: [GenderAPI.io accuracy methodology](https://www.genderapi.io/accuracy-methodology)

- [Our methodology and current evidence limits](https://www.genderapi.io/accuracy-methodology)
- [Dated database profile](https://www.genderapi.io/data-provenance)

## Is best_guess the same as forceToGenderize?

No. NameGender documents a lower evidence threshold, with email and username behavior tied to an extracted name. GenderAPI.io nickname mode can attempt an alias association without a real-name result. Neither option guarantees a non-null or correct answer.

Sources: [NameGender API: Gender from a name](https://namegender.com/docs/ai/name.md); [NameGender API: Gender from an email](https://namegender.com/docs/ai/email.md); [NameGender API: Gender from a username](https://namegender.com/docs/ai/username.md); [GenderAPI.io V2 AI options](https://www.genderapi.io/docs/v2/ai-options)

## Which response contract was reviewed?

NameGender’s current /api/v1 documentation and OpenAPI were reviewed on 26 September 2026. This page uses the current ai_fallback, best_guess, sample_size and credits_charged names. Recheck the linked contract before integrating.

Sources: [REST API Reference — NameGender](https://namegender.com/docs); [NameGender API OpenAPI 3.1 contract, info.version 1.0.0](https://namegender.com/openapi.json)

## Sources and review date

- [GenderAPI.io V2 request parameters](https://www.genderapi.io/docs/v2/request-parameters): Reviewed 2026-09-26
- [GenderAPI.io V2 authentication](https://www.genderapi.io/docs/v2/authentication): Reviewed 2026-09-26
- [GenderAPI.io V2 responses](https://www.genderapi.io/docs/v2/responses): Reviewed 2026-09-26
- [GenderAPI.io V2 AI options](https://www.genderapi.io/docs/v2/ai-options): Reviewed 2026-09-26
- [GenderAPI.io V2 batch guide](https://www.genderapi.io/docs/v2/batch): Reviewed 2026-09-26
- [GenderAPI.io V2 credits and usage](https://www.genderapi.io/docs/v2/credits-and-usage): Reviewed 2026-09-26
- [GenderAPI.io accuracy methodology](https://www.genderapi.io/accuracy-methodology): Reviewed 2026-09-26
- [GenderAPI.io pricing](https://www.genderapi.io/price): Reviewed 2026-09-26
- [NameGender API: Bulk request](https://namegender.com/docs/ai/bulk.md): Reviewed 2026-09-26
- [NameGender API: Gender from an email](https://namegender.com/docs/ai/email.md): Reviewed 2026-09-26
- [NameGender API: Gender from a name](https://namegender.com/docs/ai/name.md): Reviewed 2026-09-26
- [NameGender API OpenAPI 3.1 contract, info.version 1.0.0](https://namegender.com/openapi.json): Reviewed 2026-09-26
- [Pricing — NameGender](https://namegender.com/pricing): Reviewed 2026-09-26
- [REST API Reference — NameGender](https://namegender.com/docs): Reviewed 2026-09-26
- [NameGender API: Gender from a username](https://namegender.com/docs/ai/username.md): Reviewed 2026-09-26