The ZenRows® Universal Scraper API is a versatile tool designed to simplify and enhance the process of extracting data from websites. Whether you’re dealing with static or dynamic content, our API provides a range of features to meet your scraping needs efficiently. With Premium Proxies, ZenRows gives you access to over 55 million residential IPs from 190+ countries, ensuring 99.9% uptime and highly reliable scraping sessions. Our system also handles advanced fingerprinting, header rotation, and IP management, enabling you to scrape even the most protected sites without needing to manually configure these elements. ZenRows makes it easy to bypass complex anti-bot measures, handle JavaScript-heavy sites, and interact with web elements dynamically — all with the right features enabled.

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Key Features

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JavaScript Rendering

Render JavaScript on web pages using a headless browser to scrape dynamic content that traditional methods might miss. When to use: Use this feature when targeting modern websites built with JavaScript frameworks (React, Vue, Angular), single-page applications (SPAs), or any site that loads content dynamically after the initial page load. Real-world scenarios:
  • E-commerce product listings that load items as you scroll
  • Dashboards and analytics platforms that render charts/data with JavaScript
  • Social media feeds that dynamically append content
  • Sites that hide certain content until JavaScript is rendered
Additional options:
  • Wait times to ensure elements are fully loaded
  • Interaction with the page to click buttons, fill forms, or scroll
  • Screenshot capabilities for visual verification
  • CSS-based extraction of specific elements

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Premium Proxies

Leverage a vast network of residential IP addresses across 190+ countries, ensuring a 99.9% uptime for uninterrupted scraping. When to use: Essential for accessing websites with sophisticated anti-bot systems, geo-restricted content, or when you consistently encounter blocks with standard datacenter IPs. Real-world scenarios:
  • Scraping major e-commerce platforms (Amazon, Walmart)
  • Accessing real estate listings (Zillow, Redfin)
  • Gathering pricing data from travel sites (Expedia, Booking.com)
  • Collecting data from financial or investment platforms
Additional options:
  • Geolocation selection to access region-specific content
  • Automatic IP rotation to prevent detection

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Custom Headers

Add custom HTTP headers to your requests for more control over how your requests appear to target websites. When to use: When you need to mimic specific browser behavior, set cookies, or a referer. Real-world scenarios:
  • Setting language preferences to get content in specific languages
  • Adding a referer to avoid being blocked by bot detection systems

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Session Management

Use a session ID to maintain the same IP address across multiple requests for up to 10 minutes. When to use: When scraping multi-page flows or processes that require maintaining the same IP across multiple requests. Real-world scenarios:
  • Multi-step forms processes
  • Maintaining consistent session for search results and item visits

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Advanced Data Extraction

Extract only the data you need with CSS selectors or automatic parsing. When to use: When you need specific information from pages and want to reduce bandwidth usage or simplify post-processing. Real-world scenarios:
  • Extracting pricing information from product pages
  • Gathering contact details from business directories
  • Collecting specific metrics from analytics pages

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Language agnostic

While Python examples are provided, the API works with any programming language that can make HTTP requests.

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Parameter Overview

Customize your scraping requests using the following parameters:
PARAMETERTYPEDEFAULTDESCRIPTION
apikey requiredstringGet Your Free API KeyYour unique API key for authentication
url requiredstringThe URL of the page you want to scrape
js_renderbooleanfalseEnable JavaScript rendering with a headless browser. Essential for modern web apps, SPAs, and sites with dynamic content.
js_instructionsstringExecute custom JavaScript on the page to interact with elements, scroll, click buttons, or manipulate content. Use when you need to perform actions before the content is returned.
custom_headersbooleanfalseEnables you to add custom HTTP headers to your request, such as cookies or referer, to better simulate real browser traffic or provide site-specific information.
premium_proxybooleanfalseUse residential IPs to bypass anti-bot protection. Essential for accessing protected sites.
proxy_countrystringSet the country of the IP used for the request (requires Premium Proxies). Use for accessing geo-restricted content or seeing region-specific content.
session_idintegerMaintain the same IP for multiple requests for up to 10 minutes. Essential for multi-step processes.
original_statusbooleanfalseReturn the original HTTP status code from the target page. Useful for debugging in case of errors.
allowed_status_codesstringReturns the content even if the target page fails with specified status codes. Useful for debugging or when you need content from error pages.
wait_forstringWait for a specific CSS Selector to appear in the DOM before returning content. Essential for elements that load asynchronously.
waitinteger0Wait a fixed amount of milliseconds after page load. Use for sites that load content in stages or have delayed rendering.
block_resourcesstringBlock specific resources (images, fonts, etc.) from loading to speed up scraping and reduce bandwidth usage. Enabled by default, carefull when changing it.
json_responsestringfalseCapture network requests in JSON format, including XHR or Fetch data. Ideal for intercepting API calls made by the web page.
css_extractorstring (JSON)Extract specific elements using CSS selectors. Perfect for targeting only the data you need from complex pages.
autoparsebooleanfalseAutomatically extract structured data from HTML. Great for quick extraction without specifying selectors.
response_typestringConvert HTML to other formats (Markdown, Plaintext, PDF). Useful for content readability, storage, or to train AI models.
screenshotbooleanfalseCapture an above-the-fold screenshot of the page. Helpful for visual verification or debugging.
screenshot_fullpagebooleanfalseCapture a full-page screenshot. Useful for content that extends below the fold.
screenshot_selectorstringCapture a screenshot of a specific element using CSS Selector. Perfect for capturing specific components.
screenshot_formatstringChoose between png (default) and jpeg formats for screenshots.
screenshot_qualityintegerFor JPEG format, set quality from 1 to 100. Lower values reduce file size but decrease quality.
outputsstringSpecify which data types to extract from the scraped HTML.

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Pricing

ZenRows® provides flexible plans tailored to different web scraping needs, starting from $69 per month. This entry-level plan allows you to scrape up to 250,000 URLs using basic requests. For more demanding needs, our Enterprise plans scale up to 38 million URLs or more. For complex or highly protected websites, enabling advanced features like JavaScript rendering (js_render) and Premium Proxies unlocks ZenRows’ full potential, ensuring the best success rate possible. The pricing depends on the complexity of the request — you only pay for the scraping tech you need.
  • Basic request: Standard rate per 1,000 requests
  • JS rendering: 5x cost
  • Premium proxies: 10x cost
  • Both (JS & proxies): 25x cost
For example, on the Business plan:
  • Basic: $0.10 per 1,000 requests
  • JS: $0.45 per 1,000
  • Proxies: $0.90 per 1,000
  • Both: $2.50 per 1,000
For detailed information about different plan options and pricing, visit our pricing page and our pricing documentation page.

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Concurrency and Response Size Limits

Concurrency determines how many requests can run simultaneously:
PlanConcurrency LimitResponse Size Limit
Developer55 MB
Startup2010 MB
Business5010 MB
Business 50010020 MB
Business 1K15020 MB
Business 2K20050 MB
Business 3K25050 MB
EnterpriseCustom50 MB
Important notes about concurrency:
  • Canceling requests on the client side does NOT immediately free up concurrency slots
  • The server continues processing canceled requests until completion
  • If you exceed your concurrency limit, you’ll receive a 429 Too Many Requests error
If response size is exceeded:
  • You’ll receive a 413 Content Too Large error
  • No partial data will be returned when a size limit is hit
Strategies for handling large pages:
  1. Use CSS selectors: Target only the specific data you need with css_extractor parameter
  2. Use response_type: Convert to markdown or plaintext to reduce size
  3. Disable screenshots: If using screenshot features, these can significantly increase response size
  4. Segment your scraping: Break down large pages into smaller, more manageable sections

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Response Headers

ZenRows provides useful information through response headers:
HeaderDescriptionExample ValueUsage
Concurrency-LimitMaximum concurrent requests allowed by your plan20Monitor your plan’s capacity
Concurrency-RemainingAvailable concurrent request slots17Adjust request rate dynamically
X-Request-CostCost of this request0.001Track balance consumption
X-Request-IdUnique identifier for this request67fa4e35647515d8ad61bb3ee041e1bbInclude when contacting support
Zr-Final-UrlThe final URL after any redirects occurred during the requesthttps://example.com/page?id=123Track redirects
Why these headers matter:
  • Monitoring usage: Track your concurrent usage and stay within limits
  • Support requests: When reporting issues, always include the X-Request-Id for faster troubleshooting
  • Cost tracking: The X-Request-Cost helps you monitor your usage per request
  • Redirection tracking: Zr-Final-Url shows where you ended up after any redirects

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Additional Considerations

Beyond the core features and limits, these additional aspects are important to consider when using the Universal Scraper API:

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Cancelled Request Behavior

When you cancel a request on the client side:
  • The server continues processing the request until completion
  • The concurrency slot remains occupied for up to 3 minutes
  • This can result in unexpected 429 Too Many Requests errors
  • Implement request timeouts carefully to avoid depleting concurrency slots

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Security Best Practices

To keep your ZenRows integration secure:
  • Store API keys as environment variables, never hardcode them
  • Monitor usage patterns to detect unauthorized use
  • Rotate API keys periodically for critical applications

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Regional Performance Optimization

To optimize performance based on target website location:
  • Consider the geographical distance between your servers and the target website
  • For global applications, distribute scraping across multiple regions - the system does it by default
  • Monitor response times by region to identify optimization opportunities
  • For region-specific content, use the appropriate proxy_country parameter

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Compression Support

ZenRows API supports response compression to optimize bandwidth usage and improve performance. Enabling compression offers several benefits for your scraping operations:
  • Reduced latency: Smaller response sizes mean faster data transfer times
  • Lower bandwidth consumption: Minimize data transfer costs and usage
  • Improved client performance: Less data to process means reduced memory usage
ZenRows supports the following compression encodings: gzip, deflate, br. To use compression, include the appropriate Accept-Encoding header in your requests. Most HTTP clients already compress the request automatically. But you can also provide simple options to enable it: 
import requests

response = requests.get(
    "https://api.zenrows.com/v1/",
    params={
        "apikey": "YOUR_API_KEY",
        "url": "https://example.com"
    },
    # Python Requests uses compression by default
    # headers={"Accept-Encoding": "gzip,  deflate"}
)
Most modern HTTP clients automatically handle decompression, so you’ll receive the uncompressed content in your response object without any additional configuration.