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

> Traffic-ranked sites in the same category.

Seonio's similar companies API on its Free $1 plan. It costs $0.00 per 1,000 companies. Seonio's docs list 1 of the 13 key fields we check: Domain.
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-similar
- [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/similar`
- 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/similar?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: 8%
- Domain: ✓

## Price

- $ per 1,000 companies: $0.00
- Per: page of 25
- 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 · Website Competitors · 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: Traffic-ranked sites in the same category.

## 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: 1,000 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. Optional: limit
- Method: POST
- Path: /api/v1/website/similar

## About the plan

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

## The 4 fields the plan's answer can hold

domain, similar site domain, monthly traffic, traffic change year over year

## Seonio's plans (10)

- [Seonio, free $1, POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/free-1-post-api-v1-website-similar/llms.txt): $0.00 per 1,000, 8% complete
- [Seonio, $10 pack, Extra Usage $10, POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/10-pack-extra-usage-10-post-api-v1-website-similar/llms.txt): 8% complete
- [Seonio, $100 pack, Extra Usage $100, POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/100-pack-extra-usage-100-post-api-v1-website-similar/llms.txt): $0.035 per 1,000, 8% complete
- [Seonio, $1,000 pack, Extra Usage $1,000, POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/1000-pack-extra-usage-1000-post-api-v1-website-similar/llms.txt): 8% complete
- [Seonio, $15 monthly, Starter, POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/15-monthly-starter-post-api-v1-website-similar/llms.txt): $0.04 per 1,000, 8% complete
- [Seonio, $30 monthly, Pro, POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/30-monthly-pro-post-api-v1-website-similar/llms.txt): $0.032 per 1,000, 8% complete
- [Seonio, $60 monthly, Business, POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/60-monthly-business-post-api-v1-website-similar/llms.txt): $0.027 per 1,000, 8% complete
- [Seonio, $120 yearly, Starter (yearly), POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/120-yearly-starter-yearly-post-api-v1-website-similar/llms.txt): $0.027 per 1,000, 8% complete
- [Seonio, $240 yearly, Pro (yearly), POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/240-yearly-pro-yearly-post-api-v1-website-similar/llms.txt): $0.021 per 1,000, 8% complete
- [Seonio, $480 yearly, Business (yearly), POST /api/v1/website/similar](https://datacircle.dev/similar-company-apis/seonio/480-yearly-business-yearly-post-api-v1-website-similar/llms.txt): $0.018 per 1,000, 8% 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/similar](https://datacircle.dev/similar-company-apis/seonio/free-1-post-api-v1-website-similar/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

- [PublicWWW, $49 pack](https://datacircle.dev/similar-company-apis/publicwww/49-pack/llms.txt): $0.0049 per 1,000, 15% complete, stored
- [CompanyPulse, £29.99 monthly](https://datacircle.dev/similar-company-apis/companypulse/29-99-monthly/llms.txt): $0.013 per 1,000, 0% complete
- [ScrapeAtlas, $89 pack](https://datacircle.dev/similar-company-apis/scrapeatlas/89-pack/llms.txt): $0.018 per 1,000, 8% complete, live
- [OpenMercantil, €57 monthly](https://datacircle.dev/similar-company-apis/openmercantil/57-monthly/llms.txt): $0.021 per 1,000, 0% complete

## 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/similar?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