# SEOmonitor, free: Related keywords API

> Access complete keyword data. Directly access our curated UK and US keyword database. Get all the keyword and domain data you need.

SEOmonitor's related keywords API on its Free trial plan. It costs $0.00 per 1,000 keywords. SEOmonitor's docs list 2 of the 6 key fields we check: Search volume, Monthly trend.
You get up to 300,000 calls a month.
We haven't run SEOmonitor through [our related keywords API benchmark](https://datacircle.dev/best-related-keywords-api.txt) yet.
This plan is free. We rank 194 plans for related keywords APIs by price. Half the plans cost $0.60 per 1,000 keywords or less.
[Keys.so's ₽34,900 monthly plan](https://datacircle.dev/related-keywords-apis/keys-so/34900-monthly/llms.txt) is the cheapest paid plan per 1,000 keywords. Keys.so's ₽34,900 monthly plan charges nothing per call. You get as many keywords as Keys.so's rate limit allows.
[seodata.dev's $4.99 monthly plan](https://datacircle.dev/related-keywords-apis/seodata-dev/4-99-monthly/llms.txt) covers any number of keywords. seodata.dev's $4.99 monthly plan costs less up front than Keys.so's ₽34,900 monthly plan.
[Bing Webmaster Tools](https://datacircle.dev/related-keywords-apis/bing-webmaster-tools/free/llms.txt), [DataForSEO](https://datacircle.dev/related-keywords-apis/dataforseo/top-up-from-50-pay-as-you-go-post-v3-dataforseo-labs-google-keyword-ideas-live/llms.txt) and [Mangools](https://datacircle.dev/related-keywords-apis/mangools/15-monthly/llms.txt) are the best related keywords API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/related-keywords-apis/seomonitor/free
- [Related keywords API: the 7 best providers compared](https://datacircle.dev/best-related-keywords-api.txt)
- Get it: https://www.seomonitor.com/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=related-keywords-api-pricing
- Request: `GET https://apigw.seomonitor.com/v3/research/v3.0/related-keywords`
- API key: with the plan, on https://www.seomonitor.com/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=related-keywords-api-pricing
- Its API docs: https://api-docs.seomonitor.com/api-23256208?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=related-keywords-api-pricing
- Sold by: SEOmonitor (https://www.seomonitor.com?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=related-keywords-api-pricing)
- Checked: 2026-11-06

## In the answer

- Completeness: 33%
- Search volume: ✓
- Monthly trend: ✓

## Price

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

## Charges

- Start fee: $0.00
- Also pays for: 50 other calls

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Access complete keyword data. Directly access our curated UK and US keyword database. Get all the keyword and domain data you need.

## Data

- Freshness: 30 days
- Keep data: no limit
- Use data: Terms of Use, 6. Acceptable Use: "The Customer agrees not to: exceed published or communicated usage/rate limits, probe, scrape, or overload the Service, reverse engineer, copy, or create derivative works of the Platform, resell or provide the Service to third parties except as expressly permitted, or use the Service unlawfully or to infringe others' rights." 3. Eligibility and Accounts: "Accounts and credentials may not be shared outside the Customer's organisation or resold without our written [...]"

## Plan

- Pay: $0
- Enough for: 300,000 calls a month

## Rate limit

- Per day: 10,000
- Per second: 10
- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: campaign_id, keyword. Optional: limit, offset, order_by, order_direction, search
- Method: GET
- Path: /research/v3.0/related-keywords

## About the plan

- Plan: Free trial
- Who can get it: anyone with a valid business email

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

keyword, search volume, monthly searches, keyword relevance

## SEOmonitor's plans (3)

- [SEOmonitor, free](https://datacircle.dev/related-keywords-apis/seomonitor/free/llms.txt): $0.00 per 1,000, 33% complete, 30 days
- [SEOmonitor, €299 monthly](https://datacircle.dev/related-keywords-apis/seomonitor/299-monthly/llms.txt): $0.0011 per 1,000, 33% complete, 30 days
- [SEOmonitor, €2,990 yearly](https://datacircle.dev/related-keywords-apis/seomonitor/2990-yearly/llms.txt): $0.00093 per 1,000, 33% complete, 30 days

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

- `GET /research/v3.0/related-keywords`: [SEOmonitor, free](https://datacircle.dev/related-keywords-apis/seomonitor/free/llms.txt)

## SEOmonitor's APIs (8)

- [SEOmonitor: ChatGPT scraper API pricing, 3 plans](https://datacircle.dev/chatgpt-scraper-apis/seomonitor/free/llms.txt)
- [SEOmonitor: Gemini scraper API pricing, 3 plans](https://datacircle.dev/gemini-scraper-apis/seomonitor/free/llms.txt)
- [SEOmonitor: Google AI Overview scraper API pricing, 3 plans](https://datacircle.dev/google-ai-overview-scraper-apis/seomonitor/free/llms.txt)
- [SEOmonitor: keyword research API pricing, 3 plans](https://datacircle.dev/keyword-research-apis/seomonitor/free/llms.txt)
- [SEOmonitor: ranked keywords API pricing, 3 plans](https://datacircle.dev/ranked-keywords-apis/seomonitor/free/llms.txt)
- [SEOmonitor: related keywords API pricing, 3 plans](https://datacircle.dev/related-keywords-apis/seomonitor/free/llms.txt)
- [SEOmonitor: Perplexity scraper API pricing, 3 plans](https://datacircle.dev/perplexity-scraper-apis/seomonitor/free/llms.txt)
- [SEOmonitor: SERP API pricing, 3 plans, GET /rank-tracker/v3.0/keywords/daily-ranks](https://datacircle.dev/serp-apis/seomonitor/free-trial-get-rank-tracker-v3-0-keywords-daily-ranks/llms.txt)
- [SEOmonitor: SERP API pricing, 3 plans, GET /rank-tracker/v3.0/keywords](https://datacircle.dev/serp-apis/seomonitor/free-trial-get-rank-tracker-v3-0-keywords/llms.txt)
- [SEOmonitor: SERP API pricing, 3 plans, GET /rank-tracker/v3.0/keywords/top-results](https://datacircle.dev/serp-apis/seomonitor/free-trial-get-rank-tracker-v3-0-keywords-top-results/llms.txt)

## SEOmonitor: related keywords API alternatives

- [DataForSEO, top-up from $50, Pay as you go, POST /v3/keywords_data/google_ads/keywords_for_keywords/live](https://datacircle.dev/related-keywords-apis/dataforseo/top-up-from-50-pay-as-you-go-post-v3-keywords-data-google-ads-keywords-for-keywords-live/llms.txt): $0.0045 per 1,000, 67% complete, live
- [AnyAPI, pay as you go, Pay per call with x402 and MPP, POST /v1/run/seo.related_keywords](https://datacircle.dev/related-keywords-apis/anyapi/pay-as-you-go-pay-per-call-with-x402-and-mpp-post-v1-run-seo-related-keywords/llms.txt): $0.16 per 1,000, 100% complete, 1 month
- [QuanticData, $299 monthly](https://datacircle.dev/related-keywords-apis/quanticdata/299-monthly/llms.txt): $0.167 per 1,000, 0% complete, live
- [OutlierKit, $1,999 yearly](https://datacircle.dev/related-keywords-apis/outlierkit/1999-yearly/llms.txt): $0.833 per 1,000, 33% 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 2026-11-06.

- https://api-docs.seomonitor.com/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=related-keywords-api-pricing
- https://api-docs.seomonitor.com/api-23256208?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=related-keywords-api-pricing
- https://help.seomonitor.com/en/articles/2285726-seomonitor-terms-of-use?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=related-keywords-api-pricing
- https://help.seomonitor.com/en/articles/6824373-seomonitor-pricing-plans-billing-and-usage-limits?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=related-keywords-api-pricing
- https://www.seomonitor.com/apis-integrations?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=related-keywords-api-pricing
- https://www.seomonitor.com/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=related-keywords-api-pricing