Stealth Mode

What Stealth Mode Solves

Many websites actively block automated HTTP requests. Common defenses include:

JavaScript rendering requirements — pages that return blank HTML without executing scripts
Enterprise bot protection — services that fingerprint and block non-browser traffic
Request fingerprinting — detection based on HTTP headers, TLS handshake characteristics, or behavioral signals

Standard extraction (stealth: false) sends a direct HTTP request. This works well for the vast majority of public websites and is both fast and cost-efficient.

Stealth mode routes the request through our premium unblocker, which handles rendering and bypasses bot-protection layers. Use it only when standard extraction returns incomplete content or fails.

When to Use Stealth vs Normal

Situation	Recommendation
Public articles, blogs, documentation	Normal extraction (1 credit/URL)
E-commerce product pages	Try normal first; use stealth if blocked
Sites requiring JavaScript to render content	Stealth mode
Sites with heavy bot protection	Stealth mode
High-volume batch extraction	Normal mode; fall back to stealth on failure

Example

curl -X POST https://api.serpex.dev/api/crawl \
  -H "Authorization: Bearer sk_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "urls": ["https://example-protected-site.com/product/123"],
    "stealth": true,
    "format": "html"
  }'

import { SerpexClient } from "serpex";

const client = new SerpexClient("sk_your_api_key");

const result = await client.extract({
  urls: ["https://example-protected-site.com/product/123"],
  stealth: true,
  format: "html",
});

if (result.results[0].success) {
  // Parse structured data from HTML
  console.log(result.results[0].html);
} else {
  console.error(result.results[0].error);
}

from serpex import SerpexClient

client = SerpexClient("sk_your_api_key")

result = client.extract({
    "urls": ["https://example-protected-site.com/product/123"],
    "stealth": True,
    "format": "html",
})

if result.results[0].success:
    # Parse structured data from HTML
    print(result.results[0].html)
else:
    print(result.results[0].error)

Response

The response shape is identical to normal extraction. The stealth field in the metadata indicates stealth mode was active.

{
  "results": [
    {
      "url": "https://example-protected-site.com/product/123",
      "success": true,
      "html": "<!DOCTYPE html><html>...",
      "status_code": 200
    }
  ],
  "metadata": {
    "total_urls": 1,
    "processed_urls": 1,
    "successful_crawls": 1,
    "failed_crawls": 0,
    "credits_used": 5,
    "stealth": true,
    "response_time": 11000,
    "timestamp": "2025-06-21T10:30:00.000Z"
  }
}

Performance

Stealth requests are significantly slower than normal extraction — each one routes through a premium browser-rendering unblocker that executes JavaScript and clears anti-bot challenges.

Mode	Typical time per URL
Normal extraction	~1–5s
Stealth	~7–15s (up to ~25s for JavaScript-heavy sites)

Set your client timeout to at least 60 seconds for stealth requests. Batch requests (up to 10 URLs) are processed concurrently, so total time is bounded by the slowest URL — not the sum.

Cost

Stealth mode costs 5 credits per URL, compared to 1 credit per URL for normal extraction. Only use it when standard extraction is insufficient.

Normal extraction: 1 credit/URL
Stealth mode: 5 credits/URL
Cache hits: 0 credits regardless of mode

Failed stealth requests are not charged.