# Seonio, free $1, POST /api/v1/website/competitors: Similar companies API

> The sites competing for the same organic keywords, best first.

Seonio's similar companies API on its Free $1 plan. It costs $0.00 per 1,000 companies. Seonio's docs list 2 of the 13 key fields we check: Description, Headquarters.
We haven't run Seonio through [our similar companies API benchmark](https://datacircle.dev/best-similar-companies-api.txt) yet.
This plan is free. We rank 135 plans for similar companies APIs by price. Half the plans cost $1.33 per 1,000 companies or less.
[PublicWWW's $499 monthly plan](https://datacircle.dev/similar-company-apis/publicwww/499-monthly/llms.txt) costs the least per 1,000 companies: $0.000055. PublicWWW charges for each page of results. We count 1,000,000 companies on each page to get the $0.000055 price.
[ZoomInfo's $45 pack](https://datacircle.dev/similar-company-apis/zoominfo/45-pack/llms.txt) covers any number of companies. ZoomInfo's $45 pack costs less up front than PublicWWW's $499 monthly plan.
[ScrapeAtlas](https://datacircle.dev/similar-company-apis/scrapeatlas/19-pack/llms.txt), [LeadMagic](https://datacircle.dev/similar-company-apis/leadmagic/499-monthly-professional-post-v3-companies-lookalike/llms.txt) and [Tomba](https://datacircle.dev/similar-company-apis/tomba/449-monthly/llms.txt) are the best similar companies API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/similar-company-apis/seonio/free-1-post-api-v1-website-competitors
- [Similar companies API: the best of 20+ providers compared](https://datacircle.dev/best-similar-companies-api.txt)
- Get it: https://seonio.com/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=similar-companies-api-pricing
- Request: `POST https://seonio.com/api/v1/website/competitors`
- API key: with the plan, on https://seonio.com/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=similar-companies-api-pricing
- Its API docs: https://seonio.com/product/api/website/competitors?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=similar-companies-api-pricing
- Sold by: Seonio (https://seonio.com?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=similar-companies-api-pricing)
- Checked: 2026-11-06

## In the answer

- Completeness: 15%
- Description: ✓
- Headquarters: ✓

## Price

- $ per 1,000 companies: $0.00
- Per: page of 15
- Billing: free

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: Keyword Research · Keyword Difficulty · Keyword Intent · Keyword Demographics · Keyword Clustering · Keyword Suggestions · Keyword Metrics by Country · SERP · SERP Scraper · Scraper · Website Traffic · Website Ranking · Website Category · Similar Websites · URL Stats · URL Keywords · Website Stats · Backlink History · Backlink Table · AI Visibility Report · AI Visibility Result · Site Audit · Site Audit Result · Seonio SEO Agent · SEO Page Checker

## Overage

- Units cap: hard

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: The sites competing for the same organic keywords, best first.

## Data

- Keep data: no limit
- Use data: [...] you may use reports, API responses, and outputs generated through your account for: your internal business purposes, your own websites, products, applications, and projects, client work performed by you or your organization, integrations that use Seonio data as part of a broader product or workflow, provided that you comply with these Terms and applicable law [...] You must not: resell standalone access to Seonio, resell or sublicense API access, API keys, or your account, resell raw datasets, raw API responses, or raw outputs as a separate data product, use the Service or outputs to build a substantially similar competing service without our written permission, misrepresent Seonio outputs as official, guaranteed, real-time, or independently verified data, remove or obscure any usage restrictions, source notices, or attribution requirements that may be shown in the Service

## Plan

- Pay: $0
- You get: $1
- Enough for: 20 pages, once
- Expires: 30 days after the account is verified

## Rate limit

- Per second: 5
- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: domain_name
- Method: POST
- Path: /api/v1/website/competitors

## About the plan

- Plan: Free $1
- Who can get it: anyone with a verified account

## The 12 fields the plan's answer can hold

target, country, keywords checked, competitor domain, competitor score, competitor domain authority, shared keywords, overlap percentage, average position, competitor organic keywords, competitor traffic, updated at

## Seonio's plans (10)

- [Seonio, free $1, POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/free-1-post-api-v1-website-competitors/llms.txt): $0.00 per 1,000, 15% complete
- [Seonio, $10 pack, Extra Usage $10, POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/10-pack-extra-usage-10-post-api-v1-website-competitors/llms.txt): 15% complete
- [Seonio, $100 pack, Extra Usage $100, POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/100-pack-extra-usage-100-post-api-v1-website-competitors/llms.txt): $2.899 per 1,000, 15% complete
- [Seonio, $1,000 pack, Extra Usage $1,000, POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/1000-pack-extra-usage-1000-post-api-v1-website-competitors/llms.txt): 15% complete
- [Seonio, $15 monthly, Starter, POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/15-monthly-starter-post-api-v1-website-competitors/llms.txt): $3.333 per 1,000, 15% complete
- [Seonio, $30 monthly, Pro, POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/30-monthly-pro-post-api-v1-website-competitors/llms.txt): $2.667 per 1,000, 15% complete
- [Seonio, $60 monthly, Business, POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/60-monthly-business-post-api-v1-website-competitors/llms.txt): $2.222 per 1,000, 15% complete
- [Seonio, $120 yearly, Starter (yearly), POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/120-yearly-starter-yearly-post-api-v1-website-competitors/llms.txt): $2.222 per 1,000, 15% complete
- [Seonio, $240 yearly, Pro (yearly), POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/240-yearly-pro-yearly-post-api-v1-website-competitors/llms.txt): $1.778 per 1,000, 15% complete
- [Seonio, $480 yearly, Business (yearly), POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/480-yearly-business-yearly-post-api-v1-website-competitors/llms.txt): $1.482 per 1,000, 15% complete

## Seonio's calls for this API (2)

- `POST /api/v1/website/similar`: [Seonio, free $1, POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/free-1-post-api-v1-website-similar/llms.txt)
- `POST /api/v1/website/competitors`: [Seonio, free $1, POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/free-1-post-api-v1-website-competitors/llms.txt)

## Seonio's APIs (8)

- [Seonio: related keywords API pricing, 10 plans](https://datacircle.dev/related-keywords-apis/seonio/free/llms.txt)
- [Seonio: backlink API pricing, 10 plans](https://datacircle.dev/backlink-apis/seonio/free/llms.txt)
- [Seonio: web scraping API pricing, 10 plans](https://datacircle.dev/web-scraping-apis/seonio/free/llms.txt)
- [Seonio: keyword research API pricing, 10 plans, POST /api/v1/keywords/country](https://datacircle.dev/keyword-research-apis/seonio/free-1-post-api-v1-keywords-country/llms.txt)
- [Seonio: keyword research API pricing, 10 plans, POST /api/v1/keywords/global](https://datacircle.dev/keyword-research-apis/seonio/free-1-post-api-v1-keywords-global/llms.txt)
- [Seonio: SERP API pricing, 10 plans, POST /api/v1/serp/country](https://datacircle.dev/serp-apis/seonio/free-1-post-api-v1-serp-country/llms.txt)
- [Seonio: SERP API pricing, 10 plans, POST /api/v1/serp/scraper](https://datacircle.dev/serp-apis/seonio/free-1-post-api-v1-serp-scraper/llms.txt)
- [Seonio: similar companies API pricing, 10 plans, POST /api/v1/website/competitors](https://datacircle.dev/similar-company-apis/seonio/free-1-post-api-v1-website-competitors/llms.txt)
- [Seonio: ranked keywords API pricing, 10 plans, POST /api/v1/url/keywords](https://datacircle.dev/ranked-keywords-apis/seonio/free-1-post-api-v1-url-keywords/llms.txt)
- [Seonio: ranked keywords API pricing, 10 plans, POST /api/v1/website/ranking](https://datacircle.dev/ranked-keywords-apis/seonio/free-1-post-api-v1-website-ranking/llms.txt)
- [Seonio: domain authority API pricing, 10 plans, POST /api/v1/url/stats](https://datacircle.dev/domain-authority-apis/seonio/free-1-post-api-v1-url-stats/llms.txt)
- [Seonio: domain authority API pricing, 10 plans, POST /api/v1/website/stats](https://datacircle.dev/domain-authority-apis/seonio/free-1-post-api-v1-website-stats/llms.txt)

## Seonio: similar companies API alternatives

- [Findymail, $2,490 yearly](https://datacircle.dev/similar-company-apis/findymail/2490-yearly/llms.txt): $1.383 per 1,000, 23% complete
- [LinkCensus, $149 pack](https://datacircle.dev/similar-company-apis/linkcensus/149-pack/llms.txt): $1.49 per 1,000, 15% complete, stored
- [DiscoLike, $1,599 monthly](https://datacircle.dev/similar-company-apis/discolike/1599-monthly/llms.txt): $1.50 per 1,000, 69% complete, 30 days
- [The Companies API, $950 yearly](https://datacircle.dev/similar-company-apis/the-companies-api/950-yearly/llms.txt): $1.583 per 1,000, 92% complete, stored

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-06.

- https://seonio.com/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=similar-companies-api-pricing
- https://seonio.com/product/api?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=similar-companies-api-pricing
- https://seonio.com/product/api/website/competitors?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=similar-companies-api-pricing
- https://seonio.com/terms?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=similar-companies-api-pricing