This is a comparison of web search APIs (SERP APIs) for LLM-powered AI workflows and agents.
Why Use a Search API With an AI Workflow?
You may need a web search API if you’re building an LLM-powered system and want to retrieve relevant web content to include in the context you provide to the LLM.
For example, if you’re creating a fact checking tool, you might want to search the web and retrieve content relating to a fact that your system is checking.
How Do AI Agents Use Web Search APIs?
If you’re developing an AI agent, you’ll typically want it to make use of web search APIs through functionality baked into LLMs known as ‘tool-calling’, ‘tool-use’ or ‘function-calling’.
Frameworks such as LangChain have support for tool-/function-calling and have off-the-shelf integrations with many of the APIs (e.g. see LangChain’s search tool integrations.) Alternatively, you may be able to connect your agent to your chosen provider via a corresponding MCP server. Another option is to define a custom tool to call your chosen web search API.
Web Search API Pricing
** Firecrawl pricing is per result rather than per call. Each call can have multiple results.
What to Consider When Choosing a Web Search API
1. Underlying Search Index
Different services use different search indexes to retrieve their results.
Many services are wrappers around Google Search and should therefore return very similar results to each other. (These list ‘Google’ in the ‘Search Index’ column of the table above.)
Other services have their own indexes and may return very different sets of results.
Just as you may prefer Google over Bing search when you’re searching manually, you may prefer the results from one web search API over those from another.
2. Amount of Content for Each Search Result
Different services return different amounts of information for each search result. This can have a big impact on the effectiveness of your RAG workflow or agent.
In some cases you may prefer a service that returns relatively long snippets of content even if it costs more per request. In others you may find that smaller snippets of content are fine or even preferable as the LLM’s prompt ends up being more focussed.
3. Pricing
Prices vary considerably between services.
When you’re comparing prices, be aware that some services have optional parameters that, if you need them, can significantly impact pricing, e.g. doubling the cost of requests.
4. Latency
Services differ widely in how quickly they respond to requests.
Low cost services that work by scraping Google (these will list ‘Google’ in the ‘Search Index’ column) may be much slower than services that query their own indexes. These ‘Google wrapper’ services sometimes offer a choice of more expensive, faster options and cheaper, slower options.
5. Rate Limits
All services are limited, to some extent, in the rate of requests they can handle. Some have fixed rate limits that they make public.
6. Other Terms and Conditions
Depending on the nature of your business, factors such as a provider’s privacy policies and/or the country where they operate their servers may be very important.
Some of the links in this article are affiliate links. This means I may earn a commission if you make a purchase through them—at no extra cost to you.