Scaling keyword research is still one of SEO’s toughest challenges. Clunky tools, noisy data, and inconsistent outputs slow teams down and distract from what actually drives results.
A keyword research API addresses this by delivering structured, accurate insights directly into your workflow, which helps teams move faster and act on real opportunities. 📊
These APIs provide access to essential metrics like search volume, keyword difficulty, and SERP context, which makes it easier to automate research and support data-driven strategies.
Choosing the right API, however, isn’t just about features. It’s about fit, accuracy, and how well it integrates with your workflow. ⚙️
To help you find the right fit, here are 7 keyword research API tools that stand out for SEO professionals who rely on speed, precision, and scale.
What Matters Most in Keyword Research API Tools
Look for APIs that integrate smoothly into your systems, which allows teams to automate workflows and scale keyword research without constant manual adjustments or complex setups.
Check if the tools segment data by location or language, to allow for precise keyword targeting in local SEO strategies and geographically tailored campaigns.
Strong options include data points like search volume, cost per click, keyword difficulty, SERP elements like People Also Ask, and related terms that match business goals. 🎯
Advanced features like keyword gap analysis and competitor overlap reports offer strategic insights, which help identify missed opportunities and track shifting demand across markets.
Access to trustworthy keyword data enables smarter content planning and improves how effectively your content connects with what people are searching for. 🔎
7 Best Keyword Research API Options for Growth
To scale SEO efforts and unlock smarter insights, pros need tools that go beyond manual research. These 7 keyword research APIs deliver the data and speed that top strategies demand.
1. Search Atlas
Search Atlas centralizes keyword research within a single platform, which removes the need for separate APIs or third-party data integrations.
Its tools deliver keyword volume, CPC, difficulty, and intent insights to support search strategy and content development.
The platform makes it easier to discover new opportunities with question-based terms, related variants, and localized keywords for regional campaigns.
The Content Genius feature uses AI to surface relevant keywords, search intent, and structure from top-ranking pages. It helps you create content that’s optimized, natural, and built to rank.
Search Atlas Popular Features
- Keyword Research. Analyze search volume, competition level, CPC, and intent across national, regional, and city-specific queries.
- Keyword Magic Tool. Discover keyword ideas, variations, and related terms by entering a seed keyword, along with intent and CPC insights.
- Keyword Gap. Compare keyword coverage between your domain and competitors to highlight missed opportunities.
- Keyword Rank Tracker. Monitor daily position changes and receive automatic alerts for significant keyword movement.
- Keyword Lists. Organize and save keyword groups to support research workflows and collaborative planning.
- Regional Keyword Data. Access precise keyword metrics filtered by location to guide hyperlocal SEO targeting.
- Content Planner. Build structured content plans using automated keyword grouping and topic suggestions aligned with your goals.
Search Atlas Limitations
- Users must track OTTO SEO AI credit usage before activating automations.
- Advanced tools feel complex at first, though onboarding sessions and ongoing support are available to help.
Search Atlas Pricing
| Starter plan | Growth plan | Pro plan | |
|---|---|---|---|
| Price: | $99 monthly | $199 monthly | $399 monthly |
| Free OTTO Activation | 1 | 2 | 4 |
| User Seats | 2 | 3 | 5 |
| GSC Projects | 5 | 15 | 100 |
| Keywords per Site | Top 10K | Top 100K | Top 1M |
| Keyword Rank Tracking Projects | 20 | 50 | 1000 |
| Backlink Analyzer Projects | 2 | 5 | 5 |
| Keyword Explorer, Keyword Magic, Rank Tracker, and Keyword Gap Analysis | Unlimited use | Unlimited use | Unlimited use |
| GSC Keywords Tracking per SIte | Top 10,000 | Top 100,000 | Top 1,000,000 |
| Keyword, Competitor & Backlink Research Tools | ✅ | ✅ | ✅ |
| Content Genius – AI Blog and Landing Page Generation | ✅ | ✅ | ✅ |
Search Atlas Reviews
- G2. 4.8/5 (91 reviews)
- Capterra. 4.9/5 (64 reviews)
2. Serpstat
Serpstat offers a dedicated API for keyword research, designed to deliver structured SEO data directly into your applications, dashboards, or automated reports.
It retrieves metrics such as search volume, CPC, keyword competition, and related terms, supporting efficient content planning and SEO campaign management.
Request keyword information in real time, analyze search trends at scale, and extract insights without relying on the standard interface.
Serpstat Popular Features
- Keyword Overview. Access keyword-level data like monthly volume, cost-per-click, and competitiveness using the getKeywordsInfo method.
- Keywords Selection. Explore top organic keywords related to your term, along with ranking domains, using the getKeywords method.
- Search Suggestions. Discover alternative queries based on partial matches and user search patterns through the getSuggestions method.
- Related Keywords. Retrieve a broad list of semantically linked keywords via the getRelatedKeywords method.
Serpstat Limitations
- The dataset lacks depth compared to highly specialized SEO platforms.
- Advanced functionality is limited for lower-tier accounts, which restricts extensive analysis unless upgraded.
Serpstat Pricing
- Individual plan. $69/month, access to core features (Keyword Research, Site Analysis, Rank Tracker, Site Audit, Backlink Analysis), 5 projects, 10,000 position checks, and more.
- Team plan. $129/month, access to extended features (everything in Individual + API, Share Access, AI Tools, Batch Analysis, Scheduled Report), unlimited projects, 50,000 position checks, and more.
- Agency plan. $49/ month, access to all features (everything in Team + White Label Reports, Data Engineer Consultation), 500,000 position checks, and more.
Serpstat Reviews
- G2. 4.6/5 (462 reviews)
- Capterra. 4.7/5 (169 reviews)
3. Semrush
Semrush offers an API that allows direct access to its keyword database for integration into custom tools, internal systems, or SEO platforms.
Automate keyword discovery, gather historical advertising data, and retrieve related terms without navigating the main Semrush interface.
Two versions of the API are available, each with distinct authorization methods and different sets of available reports and features.
Semrush Popular Features
- Related Keywords. Explore synonym-based and closely related terms to build a broader list of relevant keyword opportunities.
- Keyword Ads History. Review domains that placed bids on the keyword in paid search, along with their historical ad positions.
- Broad Match Keyword. Identify variations and alternative search queries that include your target keyword or expressions.
- Phrase Questions. Gather user-style question queries that include your keyword, ideal for content targeting and intent-driven optimization.
Semrush Limitations
- Limits on how frequently automated reports are generated affect high-volume or frequent-use workflows.
- Unlocking full report functionality typically requires access to higher-tier plans, which raise overall usage costs.
Semrush Pricing
- Free. $0, unlimited time – 10 keyword searches per day, up to 10 domains per day, track 10 keywords, crawl up to 100 URLs, monitor local listings
- Pro. $139.95/month – 5 projects, 500 tracked keywords, 10,000 results per report
- Guru. $249.95/month – 15 projects, 1,500 tracked keywords, 30,000 results per report, access to historical data, content marketing platform, Looker Studio Integration
- Business. $449.95/month – 40 projects, 5,000 tracked keywords, 50,000 results per report, access to API, and extended limits.
Semrush Reviews
- G2. 4.5/5 (2,534 reviews)
- Capterra. 4.6/5 (2,286 reviews)
4. DataForSEO
DataForSEO provides a set of scalable APIs tailored for integrating keyword research and SEO insights directly into applications, dashboards, or internal systems. The Labs API supports collecting keyword ideas with associated metrics such as search intent, difficulty, and volume across Google, Bing, and other channels.
Structured endpoints return results optimized for bulk queries, ideal for platforms processing large datasets or automating keyword workflows. The service is designed for developers, tool creators, and analysts seeking high-speed access to accurate SEO and advertising data.
DataForSEO Popular Features
- Google Ads API. Retrieve keyword planner data, including search volume, impressions, CPC, and competitive intensity for Google-based campaigns.
- Bing Ads API. Extract Bing’s organic keyword volume with monthly trends and historical metrics across a full year for blended or standalone insights.
- Google Trends API. Analyze search behavior across platforms such as YouTube and Google Shopping with access to real-time and location-based trend data.
- Clickstream Data API. Compare keyword performance using blended data from clickstream sources, Google, and Bing for more precise volume distribution estimates.
DataForSEO Limitations
- Pricing presents a challenge for smaller operations.
- Some users report slower platform performance, which impacts workflow efficiency during high-usage periods.
DataForSEO Pricing
- Pay-as-you-go. $50 minimum payment/month – Pricing is based on the number of API requests made and the data retrieved.
DataForSEO Reviews
- G2. 4.1/5 (10 reviews)
- Capterra. 4.5/5 (15 reviews)
5. SpyFu
SpyFu offers an API built for embedding keyword intelligence directly into your internal tools, research platforms, or large-scale SEO workflows.
With access to 19 years of SERP data and billions of keyword metrics, it supports bulk keyword analysis, ad insights, and historical performance tracking.
Submit flexible parameters to retrieve keyword groups, competitor strategies, and intent-driven suggestions at scale.
SpyFu Popular Features
- Related Keywords. Discover semantically connected terms to expand campaign reach with relevant and competitive keyword ideas.
- Question Keywords. Identify common user queries related to your topic to support content creation and SEO intent targeting.
- “Also Buys Ads For” Keywords. View additional keywords purchased by top advertisers bidding on your selected term.
- “Also Ranks For” Keywords. Find other keywords ranking high for domains already ranking on your target term.
- Transactional Keywords. Spot search terms with strong commercial intent often linked to users close to making a purchase.
SpyFu Limitations
- Precision drop in smaller regions, affecting the reliability of insights for niche markets.
- Lacks tools for technical SEO tasks like full site audits or advanced backlink evaluation, which limits all-in-one usage.
SpyFu Pricing
- Basic Plan. $39 per month, 10k row search results, 10k data exports, 100 domain overview PDFs, 6 months of historical data, 250 sales leads & domain contacts, and 5k weekly tracked keyword rankings.
- Pro Plan. $79 per month, provides unlimited search results, unlimited data exports, unlimited domain overview PDFs, 10+ years of historical data, 500 sales leads & domain contacts, 15k weekly tracked keyword rankings, and API access.
SpyFu Reviews
- G2. 4.6/5 (513 reviews)
- Capterra. 4.5/5 (144 reviews)
6. Ahrefs
Ahrefs provides an API for keyword research that supports automated access to core metrics and search insights across global datasets.
It enables developers and SEO professionals to fetch keyword volume, difficulty scores, and ranking data for integration into dashboards or custom-built tools.
The API supports large-scale analysis by returning keyword ideas, SERP positions, and historical data without navigating the main platform.
Ahrefs Popular Features
- Volume History. Retrieve monthly search volume trends for a keyword across selected countries to monitor seasonal or long-term interest.
- Matching Terms. Collect keyword suggestions that directly include your seed term, which helps grow focused keyword sets.
- Related Terms. Uncover keywords with semantic relevance to expand coverage around a specific topic or niche.
- Search Suggestions. Generate autocomplete-style keyword prompts influenced by real user behavior, useful for content ideation.
Ahrefs Limitations
- Access is limited to a single user per plan unless upgraded, which restricts collaborative use for teams.
- Data reliability is inconsistent in less competitive or low-volume regions, affecting precision in smaller markets.
Ahrefs Pricing
- Lite Plan. $129 per month, 5 projects, track up to 750 keywords, 100,000 crawl credits.
- Standard Plan. $249 per month, 20 projects, track up to 2,000 keywords, 500,000 crawl credits.
- Advanced Plan. $499 per month, 50 projects, track up to 5,000 keywords, 1,500,000 crawl credits.
Ahrefs Reviews
- G2. 4.5/5 (555 reviews)
- Capterra. 4.7/5 (577 reviews)
7. Keywordtool.io
Keyword Tool API delivers search volume data and keyword suggestions across major platforms, which helps businesses scale keyword research without relying on manual tools.
It supports structured access to autocomplete-based data from sources like Google, YouTube, Amazon, TikTok, and more, which makes it ideal for cross-channel keyword analysis.
Integrate the API with scripts or spreadsheets to simplify repetitive research workflows and generate insights programmatically.
Keywordtool.io Popular Features
- Search Volume. Access CPC and competition metrics for each keyword, with figures aligning with Google and Bing Keyword Planner data.
- Related Keywords. Discover semantically similar search terms to expand your keyword coverage and diversify content themes.
- Question Keywords. Extract long-tail questions tied to your keyword, useful for answering user queries and guiding topic development.
- Preposition Keywords. Identify phrases containing prepositions and commercial intent, often tied to high-conversion search behavior.
Keywordtool.io Limitations
- Unusually high request volumes in a short time window trigger temporary usage restrictions.
- Daily query limits vary depending on the selected subscription plan, potentially affecting larger workflows.
Keywordtool.io Pricing
- Pro Basic. $79/month – Includes search volume data, access to more keywords, bulk search volume analysis, and 1 user account.
- Pro Plus. $89/month – Adds cost-per-click data, competition data, more keyword access, bulk analysis tools, and supports 5 user accounts.
- Pro Business. $179/month – Offers full access to search volume, CPC, and competition data, expanded keyword sets, and bulk search volume tools.
Keywordtool.io Reviews
- G2. 4.5/5 (19 reviews)
- Capterra. 4.3/5 (36 reviews)
Take Keyword Strategy Further with Search Atlas
While many SEO teams rely on APIs to bring keyword data into their systems, Search Atlas takes a different route by delivering a complete solution within a single platform.
Built-in tools support keyword discovery, local insights, competitive analysis, track performance, and create content aligned with what people actually search. 🔍
Push automation even further with OTTO SEO, the AI assistant that simplifies keyword research, applies NLP insights, and helps execute both on-page and off-page strategies.
Boost qualified traffic, improve conversions, and get more from your SEO and PPC with Search Atlas. Start your free trial today with no commitment and cancel anytime. ✨
