# Kaidn, free: Phone validation API

> Paste a number in international format to see its line type, carrier and country, and whether it is VOIP or a known disposable service.

Kaidn's Free plan for the phone validation API costs $0.00 per 1,000 phones. We check each provider's docs for 9 fields. Kaidn's docs list 6: Formats, Validity, Type, Carrier, Place, Risk.
We ran Kaidn in [our phone validation API benchmark](https://datacircle.dev/best-phone-validation-api.txt). We didn't score any Kaidn plan.
This plan is free. We rank 1,494 plans for phone validation APIs by price. Half the plans cost $3.20 or less per 1,000 phones. [326 phone validation API plans on our price sheet are free.](https://datacircle.dev/best-phone-validation-api.txt) [Trestle](https://datacircle.dev/validate-phone-apis/trestle/free/llms.txt) has a free plan with 25 calls in total. Trestle is the best phone validation API in our benchmark.
[Linq's $260 monthly plan](https://datacircle.dev/validate-phone-apis/linq/260-monthly-pro-post-v3-capability-check-imessage/llms.txt) is the cheapest paid plan per 1,000 phones. Linq's phone validation API costs nothing beyond the plan price. [Keyronne's pay-as-you-go plan](https://datacircle.dev/validate-phone-apis/keyronne/pay-as-you-go/llms.txt) costs the least for 10,000 phones a month: $0.20.
[Trestle](https://datacircle.dev/validate-phone-apis/trestle/top-up-from-10-self-serve-pay-as-you-go-get-3-0-phone-intel-phone-validation-api/llms.txt), [Signal House](https://datacircle.dev/validate-phone-apis/signal-house/top-up-from-10/llms.txt) and [Data247](https://datacircle.dev/validate-phone-apis/data247/12-pack-membership-get-v3-0-verify247-phone/llms.txt) are the best phone validation API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/validate-phone-apis/kaidn/free
- [Phone validation API in 2026: the best of 60+ compared](https://datacircle.dev/best-phone-validation-api.txt)
- Get it: https://kaidn.io/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Request: `POST https://api.kaidn.io/v1/check/phone`
- API key: with the plan, on https://kaidn.io/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Its API docs: https://kaidn.io/docs/api?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Sold by: Kaidn (https://kaidn.io?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing)
- Checked: 2026-11-11

## In the answer

- Completeness: 67%
- Formats: ✓
- Validity: ✓
- Type: ✓
- Carrier: ✓
- Place: ✓
- Risk: ✓

## Price

- $ per 1,000 phones: $0.00
- Per: call
- Billing: free

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: Check an email address · Check an IP address · Score an event · Score many events at once

## Not found

- $ per 1,000 calls that find nothing: $0.00

## In their words

- Their pitch: Paste a number in international format to see its line type, carrier and country, and whether it is VOIP or a known disposable service.

## Data

- What it checks: numbering plan
- Keep data: no limit
- Use data: You agree not to, and not to permit any third party to: use the Service unlawfully, or in violation of any applicable law, regulation, sanctions regime or third-party right, submit data you do not have a lawful basis and the necessary rights, consents or notices to submit and have processed (see section 7), use the Service as the sole or automated basis for a decision that produces legal or similarly significant effects on an individual, or to unlawfully discriminate against any person or group, including on the basis of a protected characteristic, use the Service for credit scoring, employment, insurance, housing, or any use regulated as a consumer report or background-screening service, unless you have separately arranged this with us in writing, attempt to reverse engineer, resell, sublicense, or build a competing risk-scoring product from the Service or its outputs, probe, scan, overload, circumvent rate limits, or interfere with the integrity or performance of the Service, upload malware, or use the Service to harass, defame, or harm others.

## Plan

- Pay: $0
- You get: 10,000 requests a month
- Enough for: 10,000 calls a month

## Rate limit

- Per second: 4
- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: phone. Optional: country
- Method: POST
- Path: /v1/check/phone

## About the plan

- Plan: Free
- Who can get it: anyone

## The 13 fields the plan's answer can hold

fraud score, valid, VoIP, disposable, line type, country, carrier, formatted number, recent abuse, network risk, network operators, honeypot hits, summary

## Kaidn's plans (5)

- [Kaidn, free](https://datacircle.dev/validate-phone-apis/kaidn/free/llms.txt): $0.00 per 1,000, 67% complete
- [Kaidn, $39 monthly](https://datacircle.dev/validate-phone-apis/kaidn/39-monthly/llms.txt): $0.78 per 1,000, 67% complete
- [Kaidn, $99 monthly](https://datacircle.dev/validate-phone-apis/kaidn/99-monthly/llms.txt): $0.396 per 1,000, 67% complete
- [Kaidn, $299 monthly](https://datacircle.dev/validate-phone-apis/kaidn/299-monthly/llms.txt): $0.299 per 1,000, 67% complete
- [Kaidn, contact us](https://datacircle.dev/validate-phone-apis/kaidn/contact-us/llms.txt): 67% complete

## Kaidn's calls for this API (1)

- `POST /v1/check/phone`: [Kaidn, free](https://datacircle.dev/validate-phone-apis/kaidn/free/llms.txt)

## Kaidn's APIs (2)

- [Kaidn Email verification API pricing, 5 plans](https://datacircle.dev/validate-email-apis/kaidn/free/llms.txt)
- [Kaidn Phone validation API pricing, 5 plans](https://datacircle.dev/validate-phone-apis/kaidn/free/llms.txt)

## Kaidn: phone validation API alternatives

[Kaidn alternatives: other phone validation API providers by price](https://datacircle.dev/kaidn-alternatives.txt)

We list Kaidn's cheapest paid plan first. Next we list other providers' plans closest to Kaidn in price per 1,000 phones.

- [Kaidn, $299 monthly](https://datacircle.dev/validate-phone-apis/kaidn/299-monthly/llms.txt): $0.299 per 1,000, 67% complete
- [Ihuyi, CNY 10,000 pack](https://datacircle.dev/validate-phone-apis/ihuyi/cny-10000-pack/llms.txt): $0.299 per 1,000, 22% complete
- [TCPA Litigator List, $2,999 monthly, API Titan, POST /scrub/phones/](https://datacircle.dev/validate-phone-apis/tcpa-litigator-list/2999-monthly-api-titan-post-scrub-phones/llms.txt): $0.30 per 1,000, 33% complete, stored
- [Dev.me, $300 monthly](https://datacircle.dev/validate-phone-apis/dev-me/300-monthly/llms.txt): $0.30 per 1,000, 67% complete
- [NumDetect, $19.90 pack, Basic, POST /api/v1/bulk-jobs, Bulk check, Telegram](https://datacircle.dev/validate-phone-apis/numdetect/19-90-pack-basic-post-api-v1-bulk-jobs-bulk-check-telegram/llms.txt): $0.30 per 1,000, 11% complete, live

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-11.

- https://api.kaidn.io/v1/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://kaidn.io?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://kaidn.io/docs/api?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://kaidn.io/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://kaidn.io/terms?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://kaidn.io/tools/phone-lookup?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing