Best Search APIs for AI Agents and LLMs (2026)
An LLM on its own knows only what was in its training data. A search API gives an agent or a RAG pipeline current information: it sends a query and gets back results (and often page text) that the model can read and cite.
The options changed in 2025: one major official web search API was retired and another closed to new customers. This guide covers what to look for, compares the main options with prices taken from each vendor's own pricing page, and says honestly who should pick which.
We make one of these APIs, Serpex, so read this as a vendor's guide. Every competitor figure below links to its source and carries the date it was checked, and each API gets a "pick it if" line, including the ones we compete with.
What changed: the Bing and Google APIs
If you are reading this because an older integration stopped working, this is probably why.
- Bing Search APIs were retired on August 11, 2025 (Microsoft announcement). If you still have code calling the Bing endpoints, see our Bing Search API alternative page for a migration path.
- Google's Custom Search JSON API is closed to new customers. Existing customers have until January 1, 2027 to transition, and Google points to Vertex AI Search for searching up to 50 domains (Google developer docs). That covers a limited set of domains, not the whole web. Our Google Custom Search API alternative page covers the options if you need web-wide results.
For a new project that needs web-wide results, that leaves the independent search APIs below.
How to choose a search API for an agent
Six questions decide most of it. Answer them before comparing prices.
1. Do you want retrieval or an answer?
Some APIs return results and leave the reasoning to your model. Others, such as Perplexity's Sonar, run the search and write a cited answer with their own model. If you already run a capable model with your own prompts, you probably want retrieval. If you want to remove a model call from the pipeline, an answer engine may suit you better.
2. Does page content come with the results?
Snippets are rarely enough for grounding. Check whether the API can return full page text with the search results, or whether you need a second call to an extract endpoint, with its own price and its own failure cases.
3. What controls does the request expose?
Domain include/exclude lists, date ranges, topic modes and search depth are request parameters on some APIs and missing on others. If your agent must restrict sources, check this first.
4. What exactly is billed?
Compare cost per task, not just cost per call. Check whether errors, empty results and repeated queries are charged, whether content is priced per page or per token, and whether "deep" modes cost a multiple of the base rate.
5. Is there a free tier you can test on?
A renewing monthly allowance is different from a one-time signup credit. Both are fine for evaluation; only one works for a hobby project that runs indefinitely.
6. How does it plug in?
Official SDKs, an MCP server for agent clients, and existing LangChain or LlamaIndex integrations all reduce the code you have to write.
Comparison table
Search prices are per 1,000 requests at list price. Competitor figures are from each vendor's pricing page as of 2026-08-16 (sources in the sections below). Serpex figures are from our pricing page.
| API | What it is | Search, per 1,000 | Page content | Free tier |
|---|---|---|---|---|
| Serpex | Search results as structured JSON, plus page content extraction | $0.50 – $0.80 | In the same request: 2 credits for 5 pages, 4 for 10 | 200 credits on signup, no card |
| Tavily | Search API aimed at RAG pipelines, billed in credits | $5.00 – $8.00 | include_raw_content on the search call, or a separate /extract endpoint (about $1.60 per 1,000 pages) | 1,000 credits per month |
| Exa | Embeddings-based search with a separate contents endpoint | $7.00 standard, up to $15.00 deep | $1 per 1,000 pages per content type | $20 credit on signup, plus $10 per month |
| Parallel | Web search and deep-research API for agents | $1.00 – $5.00 | Separate Extract API, $1 per 1,000 URLs | 5,000 requests per month |
| Linkup | Web search for agents, standard and deep modes | $5.00 – $6.00 | Separate Fetch endpoint, $1 – $10 per 1,000 pages | $20 credit per month |
| Brave Search API | Search on Brave's own independent index | $5.00 | LLM Context endpoint, same price per call | $5 credit per month |
| Perplexity Sonar | Answer engine: runs the search and writes the answer | $5 – $14 in request fees, plus tokens | Token billing on top of the request fee | Varies by plan |
Two tools come up in the same conversations but are not search APIs: Firecrawl crawls sites you already know and turns pages into markdown, and Jina Reader converts a URL you already have into markdown. They are covered briefly at the end.
Each API, honestly
Serpex
Serpex is a search API: real-time web search results as structured JSON, plus page content extraction. POST /api/search returns title, url, snippet and position per result; with include_content: true the top 5 or 10 results also carry their page content as markdown. A separate Extract API returns markdown or HTML for up to 10 URLs per request. There are Python and TypeScript SDKs and an MCP server (serpex-mcp).
Billing: errors are never charged, unconfirmed empty results are free, your own repeated requests within about 5 minutes cost 0 credits, and page content is billed on what was delivered. Content is best-effort; the docs say it arrives for roughly 79% of requested results.
Limits: no domain, date or topic filter parameters, no generated answers, no site crawling, no PDF extraction.
Pick it if your model does its own reasoning and you need results plus page text, cheaply and at volume. Docs · Pricing
Tavily
A credits-based search API with a broad set of RAG-specific features: answer synthesis, several search depths, domain and time filters, and Crawl, Map and Research endpoints. Its LangChain and LlamaIndex integrations are well established. Sources: tavily.com/#pricing, as of 2026-08-16; endpoints and parameters from Tavily's docs, checked 2026-09-28.
Pick it if you want the API to synthesise answers, rely on its filters, or live inside the 1,000 free monthly credits. Compare in detail: Serpex vs Tavily · Tavily alternative
Exa
Exa's embeddings-based search finds pages by meaning rather than keywords, which suits open-ended research queries. It is pure pay-as-you-go, has deep search and answer endpoints, and offers mature filtering (date ranges, domain include/exclude, categories). Contents are a separate call, with text, highlights and summaries billed separately. Source: exa.ai/pricing, as of 2026-08-16.
Pick it if semantic recall on research-style questions matters more to you than cost per query. Exa alternative
Parallel
Parallel sells web search and deep research for agents, priced per request, and is the closest to Serpex on search price in this table. Its Task API runs multi-step deep research as a managed job, and processor tiers let you trade cost for depth. Source: parallel.ai/pricing, as of 2026-08-16.
Pick it if you need managed deep research rather than search primitives. Parallel alternative
Linkup
Linkup has a standard search mode and a deep mode that does much more retrieval work per query (deep search is priced at $50 – $55 per 1,000 queries). It has licensed premium content partnerships, and the renewing $20 monthly credit is a real free tier. Source: linkup.so/pricing, as of 2026-08-16.
Pick it if you need its licensed premium sources, or your volume fits in the monthly credit. Linkup alternative
Brave Search API
Brave runs its own independent index rather than reselling another engine's results, has a strong public privacy stance with no user profiling, and charges a flat price per call, including for its LLM Context endpoint. Source: brave.com/search/api, as of 2026-08-16.
Pick it if index independence or privacy guarantees are requirements you have to answer for. Brave Search API alternative
Perplexity Sonar API
Sonar is an answer engine: you get a written, cited answer rather than a result set. You pay request fees plus token costs ($1 per million tokens in and out on Sonar; $3 in and $15 out on Sonar Pro). Deep Research mode runs multi-step research in a single call. Source: Perplexity pricing docs, as of 2026-08-16.
Pick it if you want a finished, cited answer and are happy to hand synthesis to their model. Perplexity API alternative
Not search APIs, but often paired with one
Firecrawl crawls and extracts whole sites into markdown, with depth and path control, schema-based extraction and first-class JavaScript rendering. It costs $0.75 – $3.80 per 1,000 pages on monthly billing, with 1,000 free credits a month (firecrawl.dev/pricing, as of 2026-08-16). Use it when you know which site you want crawled thoroughly. Firecrawl alternative
Jina Reader turns a URL into markdown by prefixing it, billed on response tokens ($0.050 per million, $0.045 at volume). Its 10 million free tokens are one-time and licensed for non-commercial use only (jina.ai/reader, as of 2026-08-16). Use it when you already have the URLs. Jina Reader alternative
How to evaluate before you commit
Published prices get you to a shortlist. Your own queries decide the rest.
- Build a query set from real traffic. Take 50 – 100 queries your agent actually issues, including awkward ones: long-tail, recent events, non-English.
- Run each shortlisted API on the same set within its free tier.
- Score what your model needs, not what looks good: were the right pages in the results, and did page text actually arrive for them?
- Compute cost per completed task. Include extract calls, deep-mode multipliers and token fees. Where the API reports credits per response, as Serpex does with
metadata.credits_used, sum those rather than estimating. - Check the failure path. Look at what comes back when a page cannot be fetched or a query has no results, and whether you were charged for it.
FAQ
What replaced the Bing Search API?
Microsoft retired the Bing Search APIs on August 11, 2025. If you need web-wide results, the independent search APIs in the table above are the options to evaluate. Our Bing Search API alternative page covers migration.
Can I still sign up for Google Custom Search JSON API?
No. It is closed to new customers, and existing customers have until January 1, 2027 to transition. Google suggests Vertex AI Search for searching up to 50 domains. See our Google Custom Search API alternative page.
Which search API is best for a RAG pipeline?
It depends on the answers to the six questions above. If your model writes the answer and you need page text at volume, a retrieval API that returns content with results (Serpex, or Tavily with raw content) keeps the pipeline simple. If you want the API to write the answer, look at Perplexity Sonar or Tavily's answer option. For open-ended semantic research, look at Exa.
Do I need a separate crawler alongside a search API?
Often not. Several search APIs return page text with the results or offer an extract endpoint. You need a crawler such as Firecrawl when you have to cover an entire known site rather than the pages a search returns.
How were these prices checked?
Competitor prices come from each vendor's own pricing page, dated 2026-08-16 and linked above. Prices in this category change often, so check the vendor's page before you commit.