AI Search APIs Compared: Exa vs Tavily vs Perplexity vs Linkup (2026)

Six companies now sell what most people lump together as an "AI search API," and they do not sell the same thing. Some return a finished answer with citations. Some return clean snippets for you to feed an LLM. Some return raw access to a web index that you rank yourself. Pricing is quoted in at least three incompatible units. The last broad comparison report on this category (Proxyway's) has not been updated since February 2026, and the category moved hard since then: Exa raised $250M, Tavily was acquired by Nebius, Parallel hit a $2B valuation, and Linkup, You.com, and Perplexity all shipped or recut pricing.

This guide is the hub for the category. It gives you a framework to pick by primitive, a normalized pricing table built only from verified vendor numbers, a short read on each tool, and concrete scenario-to-tool mappings. For the conceptual background on what these APIs are and how they differ from Google Custom Search, start with AI Search APIs Explained. For the broader decision framework across SERP and scraping APIs too, see How to Choose a Search API for Your AI Product.

The decision framework: Full, Fast, Index

Before you read any pricing page, decide which primitive your product actually needs. Three primitives cover the category.

Full. You send a query and get back a synthesized, cited answer. The vendor runs the retrieval, reads the sources, and writes the response. You pay for that generation whether or not you wanted it. This is Perplexity Sonar and the deep-research tiers of Parallel and You.com. Use it when you want a finished answer and do not want to run your own synthesis step.

Fast. You send a query and get back low-latency, LLM-ready snippets: deduplicated, ranked content optimized for information density per token, with no answer written for you. You do the synthesis in your own LLM call. This is Tavily, Linkup Fast, Exa Fast and Instant, and You.com Web Search. Use it for an agent step or a RAG retrieval where you control the model.

Index. You get raw access to a web index: semantic, keyword, or both. You rank, filter, and synthesize over the results yourself. This is Exa most purely, where its embeddings index and findSimilar primitive return similar documents that keyword APIs cannot, plus independent keyword indexes like Brave. Use it when you need control over ranking or a retrieval shape that the snippet APIs do not expose.

The complication is that most vendors now span more than one tier. Exa sells an Index primitive but also ships Fast and Instant modes and a Deep mode that behaves like Full. You.com sells a Fast Web Search API and a separately billed Full Research API. The taxonomy is a property of the call you make, not the company. Pick the primitive first, then check which vendors expose it cheaply and fast enough.

A second filter is latency, and it follows the framework. Full primitives are inherently slower because synthesis takes time; the fast ones counter with specialized inference (Perplexity runs Sonar on Cerebras). Fast primitives are the sub-second tier built for an agent that a user is waiting on. Index primitives vary by mode. If a human is waiting on the response, you are almost always in the Fast tier, and the Full tier only fits workflows that tolerate seconds to minutes.

Pricing table

The table below normalizes published pricing to a common unit where possible. Most of these APIs bill per 1,000 requests, so that is the primary unit; Perplexity bills primarily per million tokens plus per-request search fees, which do not reduce cleanly to a single per-query number, so its cell is illustrative. Where a number is not publicly verifiable, the cell says "see pricing page" rather than guessing.

Prices are as of June 2026 and are taken from each vendor's own pricing pages and disclosures. Tier names, multipliers, and rates change often in this category, so confirm the current number on the vendor's pricing page before you budget. Exa's restructured pricing ($7 per 1,000 searches plus $1 per 1,000 content pages) supersedes older "$5 to $10 per 1,000" figures that still circulate in directories. Primary sources: Exa pricing and Linkup pricing.

The tools

Exa

Exa encodes the web into dense embeddings and uses next-link prediction to surface conceptually relevant pages over a proprietary index it states covers 500B+ URLs. Its findSimilar primitive (semantic similar-document retrieval) has no direct equivalent among keyword or SERP-based competitors, which is the main reason to reach for Exa over a snippet API. The mode lineup runs from Instant (100 to 200ms, shipped February 2026 for real-time agents) through Fast, Auto, and Deep, and search is $7 per 1,000 requests with content at $1 per 1,000 pages. Exa raised a $250M Series C led by Andreessen Horowitz on 20 May 2026 at a $2.2B valuation, citing 400,000+ developers and 5,000+ businesses including Cursor, Cognition, and HubSpot.

Tavily

Tavily is a real-time web search API built for AI agents and LLMs: it returns LLM-ready, deduplicated, ranked content optimized for information density per token, with a single search_depth dial spanning ultra-fast, fast, basic, and advanced. It is the cheapest entry point in the category, with a 1,000-credit free tier and basic search at 1 credit (roughly $5 to $8 per 1,000 queries). In January 2026 it shipped fast and ultra-fast modes for latency-sensitive workloads. The catch for procurement is ownership: Nebius (NASDAQ: NBIS) acquired Tavily in February 2026 for $275M, rising to up to $400M on milestones, and is folding it into a web-gateway and AI-cloud stack.

Perplexity Sonar

Sonar returns a cited, web-grounded answer (not links) through an OpenAI-compatible chat-completions endpoint, run on Cerebras inference for low latency among grounded answer engines. It is a Full primitive: you get synthesis you did not have to build, and you pay per token plus a per-request search fee, which works out to roughly $5 to $7 per 1,000 simple Sonar queries and closer to $14 to $20+ for Sonar Pro. The lineup spans Sonar, Sonar Pro, Sonar Reasoning Pro, and Sonar Deep Research; Artificial Analysis lists Sonar Pro at ~1.51s time-to-first-token. Perplexity is independent and reported a ~$20B valuation in late 2025, with some 2026 trackers citing up to ~$22.6B.

Linkup

Linkup competes on accuracy: its Deep tier ranks #1 on OpenAI's SimpleQA factuality benchmark at a 91.0% F-score, ahead of Exa (90.04%), Perplexity Sonar Pro (86%), and Tavily (73%). It returns extracted, structured answers grounded in trusted sources rather than blue links, across three tiers: Fast (beta, sub-second), Standard, and Deep. Pricing is $5 per 1,000 for searchResults and $6 per 1,000 for sourcedAnswer or structured output, with Deep at $50 to $55 per 1,000, plus a $20 monthly credit for professional-email accounts. It raised a $10M seed led by Gradient in early February 2026 and remains independent.

Parallel

Parallel, founded and led by former Twitter CEO Parag Agrawal, exposes both a fast Search API ($5 per 1,000 requests, results in roughly 1 to 5 seconds) and a Task API with a ladder of nine processor tiers from Lite ($5 per 1,000) up to Ultra8x (around $2,400 per 1,000), all returning structured JSON with per-field citations. The design lets an agent route cheap simple lookups and escalate hard tasks. Parallel claims it beats Exa, Perplexity, and GPT-5 on the BrowseComp benchmark at a large cost advantage; treat vendor benchmark claims as directional. It closed a $100M Series B led by Sequoia in April 2026 at a $2B valuation.

You.com

You.com covers the full latency spectrum on one platform: a sub-450ms Web Search API (p50 ~445ms) and a separately billed Research API whose research_effort parameter scales from Lite (<10s) to Frontier (>1,000s) and which ranked #1 on the DeepSearchQA benchmark (83.67% accuracy). In March 2026 it cut Web Search to a flat $5 per 1,000 calls and Contents to $1 per 1,000 pages (about a 90% cut), with $100 in free credits for new accounts. Founded in 2020 by Richard Socher, it raised a $100M Series C at a $1.5B valuation in September 2025 and has pivoted from consumer search to an enterprise developer and API platform.

How to choose

The framework reduces to matching your scenario to a primitive, then to the cheapest vendor that hits your latency target.

RAG pipeline. You want LLM-ready snippets per token, not a written answer, because you have your own generation step. Start with Tavily for the lowest snippet-tier cost, or Exa contents at $1 per 1,000 pages if your queries are conceptual and you want semantic ranking. When factual precision is the binding constraint, Linkup's SimpleQA lead is the reason to pay slightly more. See Exa vs Tavily for the head-to-head.

Research agent. A multi-step agent that reads and reasons benefits from a Full primitive so each step returns a cited synthesis. Parallel's Task API lets the agent escalate processor tiers by difficulty; Perplexity Sonar Deep Research and You.com Research (top of DeepSearchQA) are the alternatives. Budget for these in the tens to hundreds of dollars per 1,000 calls, not single digits.

Real-time agent step. A user is waiting, so you are in the Fast tier and latency is the constraint. Exa Instant (100 to 200ms) and Exa Fast (sub-350ms P50) are the lowest-latency options; You.com Web Search (p50 ~445ms), Tavily ultra-fast, and Linkup Fast are all in range. Stay out of the Full tier here.

Citation-backed deep research. You want a finished, defensible answer with sources. Linkup Deep leads public factuality at 91.0% SimpleQA F-score; You.com Research leads DeepSearchQA; Perplexity Sonar Deep Research gives you cited synthesis through a familiar OpenAI-compatible interface. Compare on the benchmark closest to your domain rather than the headline number. See Exa vs Perplexity Sonar and Tavily vs Perplexity Sonar for index-versus-answer tradeoffs.

Budget-constrained. All else equal, the $5-per-1,000 tier (Linkup searchResults, You.com Web Search) and Exa at $7 per 1,000 are the cheapest production starts, and each ships a real free tier you can validate on (Linkup's $20 monthly credit, You.com's $100 credit, Exa's 20,000 requests, Tavily's 1,000 credits). Test at production volume and watch P95, not just the headline price; a cheap API that fails or stalls on hard targets is not cheap. See Exa vs Linkup for the cheapest-accurate-index question specifically.

The short version

Decide the primitive first. If you want a finished cited answer, you are buying Full (Sonar, You.com Research, Parallel Task, or a Deep tier) and paying for synthesis. If you want low-latency snippets for your own LLM, you are buying Fast (Tavily, Linkup Fast, Exa Fast/Instant, You.com Web Search) and the question is price and latency. If you want raw index access and similar-document retrieval, you are buying Index, and Exa is the one with a primitive (findSimilar) the others lack. The vendors keep adding tiers across the framework, so re-read the call you are making, not the logo, and confirm every number on the vendor's own pricing page before you commit budget.