By capability · Website to API

Website to API: turn any website into a structured API your code can call

The short answer

To turn a website into an API, you point a crawling and extraction service at the pages you need, define the fields you want as a schema, and call it like any other JSON endpoint. ClawEngine renders each page in a browser environment so client-side content is present, maps it to your schema, and returns typed JSON on every request, which gives a site with no public API a stable, callable interface. You control the freshness by deciding how often you call it. It reads public, no-login pages only and respects robots.txt and Terms of Service. Plans start at $39 a month.

Clean markdown & JSON · JavaScript rendered · robots.txt respected

Last updated August 2026

Live Extraction

Endpoint · POST /v1/extract

POST

try:

Hit Extract to turn this page into clean, LLM-ready data.

robots.txt respected · public data only

Markdown · JSON · structured fields, from one API call. Crawling, rendering and extracting ...

Most of the data a business actually needs sits on a web page that will never ship an API. A supplier publishes a price list as a table. A regulator posts a licensing register you have to page through. A partner runs a portal that has no developer docs and no plans to write any. Your product needs those values in JSON, on a schedule, in a shape your code already understands.

The usual answer is to write a scraper, and it works right up until it does not. Selectors break on a redesign. A page starts rendering client-side and your parser returns empty strings. Nobody owns the job after the engineer who wrote it moves teams. Six months in you have a directory of one-off scripts and a Slack channel where people report that the numbers look stale.

A website-to-API service moves that maintenance somewhere else. You describe the fields you want rather than where they sit in the markup, and every call returns the same typed record whether the source used a clean table, nested divs, or content injected after page load. Change the source layout and the schema usually still describes what you asked for.

Two honest limits, because they decide whether this is the right tool. First, if the site publishes an official API, a bulk download or a CSV export, use that instead. It will be cheaper, faster and more stable than any crawler, and it comes with a support contract. Second, this covers public pages that need no login. ClawEngine does not fill in forms, drive multi-step browser sessions, defeat anti-bot systems or read scanned PDFs, so a portal behind authentication is out of scope by design.

CRAWL RENDER JS EXTRACT MARKDOWN JSON

Any URL in LLM-ready data out

robots.txt respected public data only

Why it works

What you get with Website to API

A schema, not a scraper

You name the fields and their types once. Nothing is pinned to the third cell of the second row, so a redesign that moves elements around does not silently empty your feed.

Renders before it reads

Sites that build their content client-side hand a plain HTTP client an empty shell. Every page loads in a browser environment first, so the values exist by the time extraction runs.

Crawl and extract in one call

A register that runs 200 pages deep is one request with a page budget, not 200 requests plus the queue and retry logic you would otherwise write and own.

What it handles

Any URL in, clean structured data out

Point ClawEngine at a public page and it crawls, renders the JavaScript and extracts clean markdown or typed JSON in one call. Define a schema for structured fields, and respect robots.txt and Terms of Service by default.

Returns typed JSON from sites that publish no API
Maps pages to a schema you define, not to CSS selectors
Renders JavaScript so client-side content is captured
Follows pagination inside a single call, with a page cap
Keeps the source URL on every record for auditing
Reads public, no-login pages and respects robots.txt

POST /v1/extract extraction result

200 · JSON

{
  "url": "https://example.com/products/atlas",
  "title": "Atlas Field Notebook",
  "markdown": "# Atlas Field Notebook\n\nDurable...",
  "data": {
    "name": "Atlas Field Notebook",
    "price": 24.00,
    "currency": "USD",
    "rating": 4.7
  },
  "links": [ "/products", "/cart" ],
  "metadata": { "rendered": true }
}

JS rendered · boilerplate stripped ✓ robots.txt respected

Why ClawEngine

One API that crawls, renders and extracts

Not a raw HTML dump, not a headless browser fleet to run, and not a brittle parser to maintain. One call crawls a public page, renders its JavaScript and returns clean markdown or typed JSON, built for RAG pipelines and AI agents.

LLM-ready output

Clean markdown or typed JSON with the boilerplate stripped, so the data drops straight into a vector store, a prompt or an agent without a cleanup step.

JavaScript rendered

Each page loads in a real browser environment before extraction, so single-page apps and client-rendered content come back complete, not as an empty shell.

Compliance-first

ClawEngine works on public, permitted data only. It respects robots.txt and site Terms of Service and honors crawl-delay, so responsible scraping is the default.

Code examples

Give a site the JSON endpoint it never shipped

Post a URL and a schema describing one record. ClawEngine renders the page, maps it to that shape and returns typed JSON. Point the same call at a listing to walk pagination and get the whole dataset in one response.

curl Turn one page into a JSON record (POST /v1/extract)

curl https://api.clawengine.ai/v1/extract \
  -H "Authorization: Bearer $CLAWENGINE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://supplier.example.com/catalog/sku-4417",
    "format": "json",
    "render": true,
    "schema": {
      "sku": "string",
      "name": "string",
      "unit_price": "number",
      "currency": "string",
      "lead_time_days": "number",
      "in_stock": "boolean"
    }
  }'

python Wrap a whole site as an internal API your services call

import os, requests

BASE = "https://api.clawengine.ai/v1"
HEADERS = {"Authorization": f"Bearer {os.environ['CLAWENGINE_API_KEY']}"}

RECORD = {
    "sku": "string",
    "name": "string",
    "unit_price": "number",
    "currency": "string",
    "in_stock": "boolean",
}

def supplier_catalog(listing_url, max_pages=200):
    """Expose a supplier site that has no API as a normal Python function."""
    resp = requests.post(
        f"{BASE}/crawl",
        headers=HEADERS,
        json={
            "url": listing_url,
            "follow": "pagination",  # keep going while a next-page link exists
            "limit": max_pages,      # cap it so a runaway listing cannot bill forever
            "render": True,          # the grid is drawn client-side on this site
            "format": "json",
            "schema": {"rows": [RECORD]},
        },
        timeout=300,
    )
    resp.raise_for_status()

    for page in resp.json()["pages"]:
        for row in page["data"]["rows"]:
            # Keep provenance so any figure can be re-checked at its source later.
            yield {**row, "source_url": page["url"]}

rows = list(supplier_catalog("https://supplier.example.com/catalog"))
print(f"{len(rows)} products, {sum(r['in_stock'] for r in rows)} in stock")

Turn a website into an API: the questions buyers ask

How do I turn a website into an API?

Point a crawling and extraction service at the pages you need, define the fields you want as a schema, and call it like a normal JSON endpoint. The service fetches the page, renders it, maps the content to your schema and returns typed records. You are not reverse engineering the site; you are describing an output shape and letting the service produce it. ClawEngine does the crawl, the rendering and the extraction in a single request.

Can I create an API from any website?

From most public websites, yes. If a page loads for a signed-out visitor and robots.txt permits crawling, an extraction service can turn it into a JSON endpoint. What you cannot reliably do is build an API on top of pages behind a login, a paywall or an active anti-bot system, because getting past those is both a technical and a legal problem. Public pages are the durable case.

How do I get data from a website that has no API?

Check three sources before you crawl anything. Many sites publish a bulk CSV, an RSS feed or an undocumented JSON endpoint their own front end calls, and any of those beats scraping. If none exists, extract from the rendered page against a schema you define, and store the source URL with every record so a value can be re-checked later. That last habit is what makes the feed auditable.

What is a website to API converter?

It is a service that sits between a web page and your code, returning JSON where the site returns HTML. You give it a URL and a description of the fields you want, and it handles fetching, rendering and mapping. The useful ones also handle crawling, so a dataset spread across paginated results arrives as one response rather than as several hundred requests you have to orchestrate.

How do I find the hidden API a website already uses?

Open the browser developer tools, go to the Network tab, filter to Fetch or XHR and reload the page. Modern sites usually load their content from a JSON endpoint, and you will see it there with its parameters. If that endpoint is public and the terms permit it, calling it directly is cleaner than parsing HTML. It can also change without warning, since it was never meant as a public contract.

Is it legal to build an API on top of another company website?

In the United States, collecting publicly available data from pages that need no login is broadly lawful, and courts have repeatedly declined to treat access to public data as unauthorized access under the Computer Fraud and Abuse Act. What still binds you is the site Terms of Use, robots.txt, copyright in creative content, and privacy law once records describe individuals. Republishing someone else data as your own product is a separate question from collecting it. This is general information, not legal advice.

How much does it cost to turn a website into an API?

The visible cost is per page crawled, and on ClawEngine that starts at $39 a month for roughly 50,000 pages. The cost people underestimate is maintenance: an in-house scraper is cheap to write and expensive to keep alive, because every redesign, every new JavaScript framework and every added pagination style lands on whoever owns the script. Price the engineering hours, not just the requests.

What breaks when you build an API from a website?

Four things, in order of how often they happen. Layout changes break position-based selectors. Client-side rendering returns an empty shell to anything that reads raw HTML. Pagination changes silently truncate a dataset, which is the dangerous one because nothing errors. And rate limits turn a working job into a partial one. Describing fields by name, rendering before extracting and capping crawl size handle the first three.

Good questions

Questions about Website to API

As fresh as your last call, because there is no cache between you and the page. Teams normally schedule a crawl at whatever interval the source actually changes: nightly for a price list, weekly for a licensing register, hourly only when the underlying page really moves that fast. Crawling more often than the source updates costs money and buys nothing.

Usually nothing, because your schema describes fields by name and type rather than by position in the markup. A moved column or a reworded heading is normally absorbed. A genuine restructure, where a field stops being published at all, will show up as nulls, so it is worth alerting on the null rate per field rather than waiting for someone downstream to notice.

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Stop wrangling raw HTML. Get LLM-ready data.

Point ClawEngine at a public page and one call crawls, renders the JavaScript and extracts clean markdown or typed JSON, ready for your RAG pipeline or AI agent. Public, permitted data only.

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Crawl · render JS · extract markdown & JSON · robots.txt respected, public data only