Building SEO tools or integrating keyword data into your applications requires reliable, scalable keyword research APIs. This comparison helps you evaluate the leading keyword research APIs based on data quality, coverage, and integration capabilities.
Keyword Research API Feature Comparison Table
|
API Provider |
Database Size |
Search Engines |
Update Frequency |
Metrics Available |
Rate Limits |
Starting Price |
Languages Supported |
|---|---|---|---|---|---|---|---|
|
DataForSEO |
2B+ keywords |
Google, Bing, Yahoo |
Daily |
Volume, CPC, Competition, Difficulty |
10 req/sec |
$0.0006/SERP |
PHP, Python, Java, Ruby |
|
Semrush |
20B+ keywords |
|
Monthly |
Volume, CPC, Competition, Intent |
3000/day |
$416.66/mo |
REST, PHP, Python |
|
Ahrefs |
12B+ keywords |
Google, YouTube |
Monthly |
Volume, CPC, Traffic Potential |
1M rows/mo |
$500/mo |
REST, Python, PHP |
|
Moz |
500M+ keywords |
|
Monthly |
Volume, Difficulty, Priority |
Custom |
$5/mo |
REST, PHP, Ruby |
|
SpyFu |
100M+ keywords |
|
Monthly |
Volume, CPC, Clicks |
Plan-based |
$39/mo |
REST, Python |
|
Keywordtool.io 
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750M+ keywords |
Google, YouTube, Bing |
Weekly |
Volume, CPC, Competition |
Plan-based |
$299/mo |
REST, PHP |
DataForSEO API – Most Comprehensive Database
DataforSEO API is a comprehensive keyword research API that delivers search volume, CPC, and competition metrics. This flexible keyword research API supports bulk requests and includes SERP feature analysis for each keyword.
Highlights
- Massive keyword database covering multiple search engines
- Real-time SERP data and competitor analysis
- Extensive documentation and code examples
Pros
- Extensive global coverage across 170+ countries
- Competitive pricing with pay-as-you-go model
- High-performance infrastructure with 99.95% uptime
Cons
- Complex API structure requires development expertise
- Limited historical data compared to competitors
- API response times can vary during peak hours
Pricing
As of November 2024:
- Pay-as-you-go model
- Real-time SERP retrieval: $0.002 per SERP
- Standard queue SERP retrieval: $0.0006 per SERP
- Bulk pricing available from $0.60 per 1,000 SERPs to $100 per purchase
Support
DataForSEO offers 24/7 live chat customer support, making it easy to get help when needed. Their technical documentation is comprehensive and regularly updated with new features and implementations.
Semrush API – Best for Competitive Analysis
Semrush API is a leading keyword research API offering detailed insights into search patterns and keyword metrics. The platform’s keyword research API provides access to their massive database of over 20 billion keywords across 142 countries.
Highlights
- Advanced competitive analysis capabilities
- Extensive keyword metrics and SERP features
- Historical data tracking and trend analysis
Pros
- Comprehensive competitive intelligence
- Regular database updates
- Multiple API endpoints for different data types
Cons
- Higher price point compared to alternatives
- Complex authentication process
- Rate limits on lower-tier plans
Pricing
As of November 2024:
- Available with Business plan: $499.95/month
- Annual billing discount: $416.66/month
- Custom API pricing for enterprise-level usage
- Volume-based pricing available for large-scale implementations
Support
Semrush provides priority support for Business plan users, including:
- Dedicated account managers
- Technical implementation assistance
- Regular training sessions
- Priority ticket resolution
Ahrefs API – Most Accurate Search Volume Data
Moz API is a trusted SEO API that delivers essential metrics like domain authority and ranking factors.
Highlights
- Industry-leading keyword accuracy
- Extensive backlink data integration
- Regular database updates
Pros
- Most accurate search volume metrics
- Comprehensive keyword difficulty scores
- Advanced filtering capabilities
Cons
- Higher entry-level pricing
- Limited free trial options
- Strict rate limiting
Pricing
As of November 2024:
- API Standard plan: $500/month
- $1 per 1,000 rows for overages
- Custom enterprise pricing available
- Volume discounts for larger implementations
Support
Ahrefs provides comprehensive support including:
- Technical documentation
- Implementation guides
- API status monitoring
- Email support system
Moz API – Best for Domain Authority Metrics
Moz API is a respected keyword research API providing reliable keyword difficulty scores and volume data. Their keyword research API includes proprietary metrics like keyword potential and organic CTR predictions.
Highlights
- Industry-standard domain authority metrics
- Comprehensive link data
- User-friendly implementation
Pros
- Reliable domain metrics
- Straightforward integration
- Flexible pricing structure
Cons
- Smaller keyword database
- Limited international coverage
- Basic rate limits on lower tiers
Pricing
As of November 2024:
- Starting at $5/month
- Tier-based pricing structure
- Usage-based scaling
- Custom enterprise solutions available
Support
Moz offers:
- Comprehensive documentation
- Code examples
- Self-serve dashboard
- Account management tools
SpyFu API – Best for PPC Research
Spyfu API is an innovative keyword research API specializing in competitor keyword analysis and search volume data. Their keyword research API includes unique features like keyword gap analysis and real-time difficulty scoring.
Highlights
- Detailed PPC competitor data
- Historical ad copy database
- Comprehensive keyword positioning
Pros
- Extensive PPC metrics
- Historical ad performance data
- Competitive intelligence features
Cons
- Limited organic search data
- US-centric database
- Basic API documentation
Pricing
As of November 2024:
- Basic Plan: $39/month ($192/year)
- Professional Plan: $79/month ($432/year)
- Team Plan: $299/month ($1,788/year)
- Custom API pricing available
Support
SpyFu provides:
- Email support for all plans
- 30-day money-back guarantee
- 4.5/5 average customer service rating
Keywordtool.io API – Best Google Ads Alternative
Keywordtool.io API is a specialized keyword research API focusing on long-tail keyword discovery across multiple search engines. The keyword research API covers Google, YouTube, Bing, Amazon, and other platforms for comprehensive keyword insights.
Highlights
- Multiple search engine coverage
- Long-tail keyword focus
- Question-based keyword suggestions
Pros
- Comprehensive long-tail data
- Multiple language support
- Regular database updates
Cons
- Higher starting price point
- Limited historical data
- Basic API documentation
Pricing
As of November 2024:
- API Lite: $299/month (€239/month annually)
- API Basic: $999/month (€799/month annually)
- API Plus: $1,999/month (€1,599/month annually)
- Custom enterprise solutions available
Support
- 24/7 customer support team
- Dedicated contact form
- Implementation assistance
- Regular feature updates
Choose the Right Keyword Research API for Your Needs
Looking to integrate keyword data into your spreadsheets without complex API implementation? Try Coefficient’s direct integrations with SEO tools like Semrush and Ahrefs. Start automating your keyword research workflows today.
