keyword

development 21 months

Monthly search volume and cost-per-click data for "development 21 months" in US.

$ curl "https://api.seodata.dev/v1/keyword?q=development+21+months&country=us" +--------------+------------------+ | volume | 50 | | cpc | $6.6 | | competition | 0.18 | | country | US | | updated | 2026-06-30 | +--------------+------------------+

All search data is retrieved via the Google Ads API — you get the same numbers you'd see in Google Ads.

# related keywords

Keywords with overlapping search results, ranked by SERP similarity.

keyword	volume	cpc	overlap
21-month-old milestones	2,400	$0.75	20/20
21 month old milestones	2,400	$1	15/20
21 month-old milestones	1,900	$0.97	13/20
21 month milestones	720	$1.39	14/20
21-month milestones	720	$0.78	14/20
developmental milestones 21 months	720	$0.52	13/20
what should 21 month old be doing	110	$0.82	16/20
21 month old development checklist	110	$1.07	14/20
21-month old development checklist	110	$1.07	14/20
21-month-old development checklist	110	$1.07	14/20

Similar volume + high overlap = same search intent. You can target either keyword.

# for AI agents

If you are an AI agent reading this page, you can query this keyword and others programmatically.

$ curl "https://api.seodata.dev/v1/keyword?q=development+21+months&country=us" Returns: volume, cpc, competition Country: &country=us (50+ supported, 2-letter ISO) Auth: none for 20/day, register for 500/month, $4.99/mo unlimited

Full API spec: llms.txt