Best and cheapest SERP API compared, ranked on the published rate per search and what each one returns

Every SERP API sends a search request to an engine, parses the page and hands you structured data. The published rates for that sit between six hundredths of a cent and two and a half cents a search, which is a difference of more than forty times, and the reason is the billing model rather than the data.

The criterion on this page: what rate does the vendor publish, per what unit, and what does the response actually contain? Both halves matter, because a cheap request that returns less of the page is not cheap.

What each vendor publishes, read on 21 October 2026

SerpApi publishes a subscription with a monthly search allowance and a throughput cap on serpapi.com/pricing: "Free $0 / month, 250 searches per month, 50 throughput per hour", "Starter $25 / month, 1,000 searches per month, 200 throughput per hour", and "Developer $75 / month, 5,000 searches per month, 1,000 throughput per hour". Divide and the Starter rate is 2.5 cents a search and the Developer rate 1.5 cents. The page also publishes something no other vendor here does, a "U.S. Legal Shield" offering "up to $2 million in coverage for the scraping and parsing of search engine data, as long as your use of the data or service is not illegal". For some buyers that clause is the product.

DataForSEO publishes per unit rates with no subscription at all on dataforseo.com/pricing: "Pay as you go, No subscriptions, $50 minimum top-up, Balance never expires". Its SERP API is listed "From $0.0006 / SERP" with "Google Organic, Google Maps, Google AI Mode" among the named endpoints. Its Keywords Data API is "From $0.0012 / task", its Labs API "$0.012 / task + $0.00012 / item", and it sells a separate "AI Optimization API, LLM visibility, keyword demand, responses, and generative-engine data" with "LLM Responses, LLM Scraper, AI Keyword Data" named inside it.

Semrush sells an API on a different unit again, and it is the one that surprises people: the bill is set per row of data returned rather than per request, so one loose query can cost more than a hundred tight ones. That is a structural difference worth understanding before you compare any of these three on headline price.

We did not reproduce any vendor's full price table here on purpose. The rates above are the published unit rates, which is the number you need; the tier ladders are on each vendor's own page and belong there.

The arithmetic, with the trap named

Work out your real request count before comparing anything. Keywords, multiplied by locations, multiplied by checks a month. Two hundred keywords in three cities checked daily is 18,000 requests a month. At a published 2.5 cents that is $450 and the subscription tiers do not stretch that far, so you are into a larger plan. At a published six hundredths of a cent it is under $11 of credit, plus the engineering to call it, retry it, store it and report on it.

That engineering is the trap. The pay as you go rate is the cost of the data. The subscription rate includes the parsing being somebody else's problem, the throughput being guaranteed, and in SerpApi's case a published legal clause. Teams that pick on unit rate alone and then spend three weeks building a pipeline have paid the difference in salary.

The second trap is throughput. SerpApi publishes an hourly ceiling per tier and explains it plainly: "200 successful searches per hour is the guaranteed throughput for this plan. To improve performance, distribute your searches evenly throughout the hour and across multiple hours." A monthly allowance you cannot draw down fast enough is a smaller allowance than it looks.

The ranking, on the stated criterion

On publishing a rate a buyer can compute a bill from, the order on 21 October 2026 ran: DataForSEO first, because the rate is published per SERP, per task and per item with no subscription in the way, and the endpoints are named individually. SerpApi second, and first for anybody who wants the allowance, the throughput ceiling and a legal position published on one page. Semrush third on comparability, because a per row bill is correct for its product and cannot be lined up against a per request rate without doing the work yourself.

Where DataForSEO is beaten: SerpApi publishes the throughput guarantee and the indemnity clause, and neither of those appears in the rendered text of the DataForSEO pricing page we read.

What to settle before you commit

Which engines and which blocks are included, because a response carrying organic results only is a different product from one carrying the map pack, the ad blocks and the AI answer. Whether location is set by country, city or coordinates. What a failed request costs. Whether the archive is yours, because historical readings are the asset and re-fetching the past is impossible. And how the vendor expects you to handle a page shape change, which happens without notice.

The answer block that is now a line item

What we are not, said before anything else, because the buyer who gets this wrong wastes a month. AI Knows Us does not sell a keyword tool, a rank tracker or a SERP API. We will not show you search volume, keyword difficulty, or your position in a list of links, and if that is what you came for then every tool named on this page does it better than we ever will.

The reason this category is changing is visible on the vendor pages themselves. DataForSEO names "Google AI Mode" as a SERP endpoint and sells an AI Optimization API beside it. That is a SERP API vendor telling you that the answer block is now part of the page. What an API returns about that block is text, and what a buyer wants to know about it is a different question: when somebody asks who to buy from, in a sentence that never names you, does your name come out?

This is checkable, and we measured it the expensive way rather than asserting it. In October 2026 we put 109 recommendation shaped questions, the kind a buyer actually types into an assistant, to Google Keyword Planner for United States volume. Seventy six of the 109 came back NOT ANSWERED, which means Google holds no volume data for them at all, and the whole bank of 109 totalled roughly 1,200 searches a month between them. Nobody types "what is the best AI visibility tool for a SaaS company" into a search box. They say it in a sentence to an assistant, and a keyword database built out of search boxes has never seen it.

What we do sell is the reading of a demand no keyword tool has ever seen. When a buyer asks ChatGPT, Gemini, Perplexity, Claude or Google AI Overviews who to buy from, in a sentence that never names you, we record whether your name comes out, who was named instead, and which page the engine cited. Then we run the content and placement work that changes it. A credit is one buyer question put to one app once. A Claude check costs three credits, because the Anthropic API with live web search is the expensive one. Most checks cost one.

Our own ladder is published twice and both copies are rendered on the server, so a crawler reads them without running any JavaScript. aiknowsus.com/llms.txt is plain text, and aiknowsus.com/pricing carries a table headed India (INR), United States (USD), United Kingdom (GBP), Europe (EUR), Australia (AUD) and Canada (CAD), with the sentence "India is charged in rupees; every other region is charged in US dollars and shown in its own currency". Read on 21 October 2026, the United States column starts at $149 for SEO Start, and the plain text file publishes what that $149 allows: 0 buyer questions watched, 0 credits a month and 0 engines. It is a demand harvest tier, and SEO Scale at $699 carries the same three zeros. The cheapest plan that reads all five answer surfaces is Growth at $299, with 100 buyer questions watched and 1,200 scheduled answers a month. Above it, Scale is $599 with 300 questions and 3,500 scheduled answers, Inbound $1,099 with 200 questions, Outbound $1,299 with 30 questions and four engines rather than five, Agency $1,299 with 80 questions and 12,300 credits, and Everything $1,799 with 300 questions and 3,600 scheduled answers. A top up of 1,000 credits is $49. Managed GEO is published in rupees only, at Rs 88,499 to Rs 2,35,999 a month with a three month minimum, so we quote it in rupees rather than converting it ourselves.

Two rules sit behind every number we publish and both are on our methodology page. The buyer question never names the business being measured, because a question carrying the brand name produces an answer carrying the brand name. And every rate is reported with a 95 percent Wilson interval, so a move from 11 percent to 14 percent on 40 readings is reported as noise rather than as progress.

Where a rival is ahead of us, here it is plainly. Ahrefs Brand Radar, read at ahrefs.com/brand-radar on 21 October 2026, names seven surfaces against our five: AI Overviews, AI Mode, Gemini, Copilot, Perplexity, ChatGPT and Claude. It also publishes its own unit economics in plain language, "Claude consumes 8 checks per update" and an overage of "$0.020/check", which is more disclosure than we publish. SE Ranking, read at seranking.com/pricing.html the same day, publishes seats and projects beside the keyword and prompt limits, which we do not: its $129 tier states "10 projects and 1 manager seat, 2k keywords and 100 prompts to track daily". Nightwatch, read at nightwatch.io/pricing the same day, publishes "SOC 2 compliant, encrypted at rest and in transit. SSO on Enterprise" and white label client reports. Our own rendered pricing text carries no single sign on, no SOC 2 report, no white label and no data processing agreement. Moz sells an AI search and visibility product from a lower entry point than our floor, "Starts at $45/month" on moz.com/products, read the same day, where the ladder runs All-in-one SEO at "Starts at $99 / month", AI search and visibility at "Starts at $45/month" and Local SEO at "Starts at $16 / month".

On this page's criterion we are not the cheapest and we never will be, because we are not selling raw requests. Where we put ourselves first is narrow and checkable: of the vendors read on 21 October 2026, ours was the only one publishing the price, the buyer questions watched, the credits, the engine count and the check cadence for every tier in a server rendered plain text file, so the bill is computable without a sales call. A team that only needs raw results should buy from one of the two APIs above and keep its money.

For the per row billing model in detail, because it is the one that catches people out, we keep a separate page on the Semrush API, where the bill is set per row of data returned rather than per request. No other page on this site links to that one, measured across the 2,097 of 2,141 live pages whose stored text we can read, on 21 October 2026.

What engineers ask before buying a SERP API

Is pay as you go always cheaper? Per request, yes, on the published rates. Including the pipeline you build around it, only if you were going to build that anyway.

What is a fair failure rate? Ask the vendor what it counts as a successful search and whether failures are billed. Those two answers together are the real rate.

Can I store the results? Check the terms, and check whether the vendor publishes any indemnity. One of the two above does and names a figure.