Zenrows General FAQ: Billing, Features, and Limits

Find answers to frequently asked questions about Zenrows web scraping, including billing cycles, supported features, and usage limits.

Does Usage Carry Over Months?

On paid plans (Build through Scale), yes: unused credits roll over for 1 additional billing period before they expire. The Free plan doesn’t roll over; credits reset at the start of each month. Enterprise rollover terms are negotiated. Separately, if you upgrade your plan mid-cycle, any unused credits (including top-ups) carry over as bonus credits on top of your new plan’s allowance. See Upgrading Your Plan.

Can I Scrape Using Browser Extensions?

Zenrows does not offer a browser extension, and our products are designed to work via API requests, proxies, and automated browsers, not through browser extensions.

Why Doesn’t Zenrows Offer a Browser Extension?

Browser extensions have significant limitations when it comes to web scraping:

1. Restricted Execution – Extensions run in a browser’s sandboxed environment, limiting their ability to bypass antibot protections.
2. Scalability Issues – A browser extension would require manual interaction, making it impractical for large-scale or automated scraping.
3. Limited Customization – Unlike our API and Browser Sessions, extensions lack the flexibility to integrate advanced scraping techniques, such as headless browsing, fingerprint evasion, and CAPTCHA handling.

How to Scrape Without a Browser Extension

Instead of using an extension, we recommend using one of our API-based solutions, which are optimized for web scraping at scale:

Fetch

• Designed for flexible, automated scraping with built-in antibot bypassing.
• Supports JavaScript rendering, Premium Proxies, and CAPTCHA handling.
• Ideal for scraping protected or dynamic pages.

Browser Sessions

• A headless browsing solution that allows full control over web automation.
• Ideal for cases where manual browser behavior replication is needed.

Residential Proxies

• Provides rotating IPs to increase anonymity.
• Best for handling IP-based blocks but requires custom browser automation for full scraping functionality.

If you’re looking for automated and scalable web scraping, our API solutions are the best fit. Let us know if you need help choosing the right approach! 🚀

Can I See the XHR / AJAX / Fetch Requests that Browsers Perform?

If you need to capture dynamic content loaded via AJAX requests, Zenrows offers different approaches depending on the product you’re using. Some products provide built-in JSON responses, while others require custom configurations to extract network requests.

More and more websites load content dynamically, meaning data is fetched via XHR, AJAX, or Fetch requests instead of being included in the initial HTML. Besides waiting for the content to load, you might want to capture these network requests, similar to how they appear in the Network tab in DevTools.

How Each Zenrows Product Handles XHR / AJAX / Fetch Requests

Fetch

• The JSON Response feature (json_response=true) captures AJAX requests automatically.
• Returns a structured JSON object containing two fields:
  • HTML – The final rendered page source.
  • XHR – An array of network requests (XHR, AJAX, Fetch), including URL, body, headers, and more.
• This feature is exclusive to Fetch and is ideal for analyzing background requests.

Learn more: JSON Response

Browser Sessions

• Does not capture network requests automatically.
• You’ll need to configure custom JavaScript code to intercept and extract XHR/AJAX calls manually on Puppeteer or Playwright.

For a step-by-step guide on capturing network requests in Playwright, check out our comprehensive Playwright guide.

Residential Proxies

• Acts as a proxy layer without modifying responses.
• To capture XHR/AJAX requests, you must configure custom request logging in your own setup (e.g., Puppeteer, Playwright, or Selenium).

By choosing the right Zenrows product and configuration, you can effectively capture network requests and analyze the data that websites load dynamically. Let us know if you need guidance on a specific use case! 🚀

Does Zenrows Bypass Antibot Solutions?

Zenrows is designed to bypass most modern antibot solutions out-of-the-box. We continuously test and optimize our systems to ensure a smooth scraping experience. However, antibot defenses vary by website, and different Zenrows products serve different purposes.

Below is an overview of how each product handles antibot measures and what to expect when using them.

Fetch

Fetch, when combined with Premium Proxies and JS Render, effectively handles most antibot measures. This setup mimics real user behavior, helping bypass bot detection mechanisms.

However, not all pages are protected equally. Many websites enforce stricter protections on internal APIs or login-restricted content. If you’re targeting such endpoints, additional configurations might be needed.

If you’re experiencing blocks despite using Premium Proxies and JS Render, refer to this guide: Using Premium + JS Render and still blocked

Residential Proxies

Residential Proxies prioritize anonymity rather than antibot bypassing. They provide IP rotation and geographic targeting but do not include built-in antibot or CAPTCHA-solving capabilities. For heavily protected websites, additional techniques may be required.

Browser Sessions

Browser Sessions is highly effective against antibot and anticaptcha solutions, using the same advanced algorithms as Fetch. However, if a website enforces a CAPTCHA challenge, we do not automatically bypass it. Solving CAPTCHAs currently requires implementing custom handling, such as integrating third-party CAPTCHA-solving services.

By choosing the right combination of Zenrows tools, you can optimize your web scraping strategy to handle even the most complex antibot defenses. If you need further assistance, feel free to reach out to our support team.

Does Zenrows Have No-Code Options?

Zenrows supports a variety of no-code platforms to help you scrape data from websites without writing a single line of code. These integrations let you connect your scraping workflows with thousands of apps like Google Sheets, Airtable, Notion, Amazon S3, and more.

These no-code integrations are ideal for marketers, analysts, product managers, and anyone looking to automate data collection without needing technical skills.

When to Use No-Code Integrations

Use Zenrows’ no-code options when you:

• Want to scrape data into a spreadsheet without writing code
• Need to automate recurring data collection tasks
• Prefer visual workflow builders over API requests
• Are integrating web data into tools like CRMs, email platforms, or dashboards

Best Practice: Start with pre-built Zenrows templates in platforms like Zapier or Make to set up your workflow in minutes.

Next Steps

Visit our Integrations Page to explore tutorials and real-world examples that walk you through setting up your first workflow.

Does Zenrows Integrate with External Tools?

Suppose you must scrape data from a website and automatically process it using a third-party tool. We offer various ways to integrate Zenrows with external software and tools. Currently, you can integrate a captcha solver or a no-code tool like Zapier/Make/Clay.

Additionally, you can build your integrations using the Zenrows output, whether HTML or JSON. A good use case for this is the autoparse feature, which returns structured data from a page.

Does Zenrows offer Custom plans?

Yes! Our custom plans are available for high-volume cases. We cannot customize public plans, as they are standardized for all our clients.

How Can I Speed Up My Requests?

Optimizing your requests can significantly improve performance and reduce response times. Below are general best practices, followed by specific recommendations for each Zenrows product.

Factors Affecting Request Speed

1. Concurrency: Sending multiple requests simultaneously can increase throughput
2. Resource Usage: Features like JavaScript rendering or waiting for specific conditions can impact speed
3. Response Size (optional): Pages with dynamic content will naturally take longer to load. Consider targeting only the necessary data or using output filters to minimize payload.
4. Success Rate: The rate of successful requests. If the success rate is low, you may need to increase the number of requests or the concurrency.

While Residential Proxies have no concurrency restrictions, other products have plan-specific limits. Monitor your performance when adjusting these settings.

Monitoring Concurrency Usage

Each response includes headers that help you manage and optimize your concurrency:

Concurrency-Limit: 200
Concurrency-Remaining: 199

These headers help you:

• Monitor how many concurrent requests your plan allows
• Track how many slots are currently available
• Adjust request volume dynamically to avoid hitting limits that may delay or throttle requests

The Concurrency-Remaining header reflects the real-time state of your concurrency usage and is the primary value our system uses to enforce limits. If it reaches zero and more requests are sent, you may receive a 429 Too Many Requests error and your IP can be temporarily blocked for 5 minutes.

If you receive a BLK0001 error (IP Address Blocked), it means your IP has exceeded the allowed error rate. The block will last for 5 minutes and will impact your ability to send new requests during that time, affecting your overall scraping speed. For more details, see our API Error Codes documentation.

Use these headers to adjust your request flow in real-time, scaling up when possible and backing off before hitting limits.

Product-Specific Recommendations

Fetch

1. Optimize JavaScript Rendering:

• Disable js_render=true for static content to improve speed
• Only enable when necessary for dynamic content or accessing protected content
• Consider the impact on response times

2. Minimize Wait Times:

• Use wait and wait_for only when required
• Set the minimum necessary wait duration
• Longer waits mean slower requests

3. Use Premium Proxies:

• Enable premium_proxy=true for faster, more consistent responses
• Particularly useful for sites with anti-bot measures
• Can reduce retries and improve overall speed

Residential Proxies

1. Request Rate Optimization:

• Monitor response times at different request rates
• Adjust based on target site performance
• Implement backoff when responses slow down

Browser Sessions

1. Resource Management:

• Disable unnecessary JavaScript execution
• Block non-essential resources (images, media, etc.)
• Optimize browser settings for faster loading

2. CAPTCHA Handling:

• Implement manual CAPTCHA solving to avoid automated delays
• Consider the impact on overall request speed

Speed Optimization Best Practices

1. Start with Baseline: Begin with standard settings and measure response times
2. Monitor Performance: Use response headers and timing metrics to track speed
3. Gradual Optimization: Make incremental changes and measure their impact
4. Smart Retries: Use exponential backoff for failed requests to maintain speed
5. Target-Specific Tuning: Adjust settings based on the specific website’s performance

While these optimizations can improve request speed, some features (like JavaScript rendering) might be necessary for your specific use case. If you need help optimizing for speed while maintaining functionality, our support team is here to assist.

How Is Usage Counted?

Your dashboard displays usage as a percentage of your plan’s total credit allowance. This percentage reflects spending across all Zenrows products, with different features consuming credits at different rates based on their credit costs.

Features like JavaScript Rendering (5 credits) or Premium Proxies (10 credits) consume more of your allowance per request than standard requests (1 credit). This means the number of API calls you make may differ from the usage percentage shown. The percentage reflects the actual credit cost of each request relative to your total allowance.

Credit resets and rollover depend on your plan tier:

Free

• Credits reset each month.
  Unused credits do not roll over.

Build, Launch, Growth, and Scale

• Credits reset each billing period.
  Unused credits roll over for 1 additional billing period before they expire.

Enterprise

• Rollover terms are negotiated as part of your contract.

If you upgrade your plan mid-cycle, unused credits carry over to your new plan. See our Pricing page for details.

How to Handle CAPTCHA-Protected Pages?

Zenrows is designed to bypass most modern antibot solutions out-of-the-box. We continuously test our service to ensure optimal performance.

Handling CAPTCHAs depends on the type of CAPTCHA and the Zenrows product you’re using.

Handling CAPTCHAs on Forms

CAPTCHAs on forms are not solved automatically. If you need to submit forms that trigger a CAPTCHA, we offer an integration with a CAPTCHA solver that might work for your use case. Learn more about it here: Using JavaScript Instructions to Solve CAPTCHAs

CAPTCHA Handling by Product

Each Zenrows product has its own approach to handling CAPTCHAs, depending on the level of antibot protection in place. While some products automatically bypass CAPTCHAs in most cases, others may require additional configurations or external solvers. Below, we outline how each product deals with CAPTCHAs and what you can do to improve your success rate.

Fetch

• Uses Premium Proxies and JS Render to bypass most antibot measures.
• If a CAPTCHA appears, you can use JavaScript Instructions to interact with the page and solve it manually or through an external CAPTCHA-solving service.

Residential Proxies

• Residential Proxies provide anonymity but do not bypass CAPTCHAs automatically.
• If CAPTCHA protection is strict, you’ll need custom handling or an external solver.

Browser Sessions

• Uses the same bypassing techniques as Fetch.
• Can handle most antibot solutions, but does not solve CAPTCHAs by default.
• If a CAPTCHA is encountered, it requires custom handling, such as integrating a CAPTCHA solver.

By choosing the right Zenrows product and implementing the appropriate CAPTCHA-handling techniques, you can minimize interruptions and improve your scraping success rate. If you need assistance with a specific case, feel free to contact our support team.

What is concurrency?

Concurrency refers to the number of ongoing requests that happen at any given time. By different means, computers and languages can call the API in parallel and wait for results while others are still running. You can use concurrency with any Zenrows plan; check out pricing for more details.

For more details, check our how-to guide on concurrency to see details about implementation in Python and JavaScript.

Important Behavior to Understand

Canceled Requests Still Count Against Your Concurrency

One crucial thing to understand is that canceling requests on the client side does NOT immediately free up concurrency slots. When you cancel a request:

1. Your client stops waiting for a response
2. But the Zenrows server continues processing the request
3. The concurrency slot remains occupied until the server-side processing completes
4. Only then is the concurrency slot released

This can lead to unexpected 429 errors if you’re canceling requests and immediately trying to make new ones, as your concurrency limit might still be reached.

Security System for Failing Requests

Zenrows implements a security system that may temporarily ban your API key if you send too many failing requests in a short period. Types of failing requests that can trigger this include:

• 429 Too Many Requests errors due to exceeding concurrency limits
• Invalid API key errors
• 400 Bad Request errors due to invalid parameters
• Other repeated API errors

If your API key gets temporarily banned, you’ll receive an error from the API. If the requests continue, the IP address might get banned for a few minutes and the requests will not even connect with the server.

Monitoring Your Concurrency Usage

You can monitor your concurrency usage through response headers:

Concurrency-Limit: 200
Concurrency-Remaining: 199
X-Request-Cost: 0.001
X-Request-Id: 67fa4e35647515d8ad61bb3ee041e1bb
Zr-Final-Url: https://httpbin.io/anything

These headers provide valuable information about your request:

• Concurrency-Limit: Your maximum concurrent request limit based on your plan
• Concurrency-Remaining: Number of additional concurrent requests you can make
• X-Request-Cost: The cost of this request (varies based on enabled features)
• X-Request-Id: Unique identifier for this request - essential when reporting issues to support
• Zr-Final-Url: The final URL after any redirects that occurred during the request

Related questions

How many concurrent requests are included in my plan?

The concurrency limit scales by plan tier, not by individual rung:

• Free: 5 concurrent requests
• Build: 20 concurrent requests
• Launch: 50 concurrent requests
• Growth: 100 concurrent requests
• Scale: 200 concurrent requests
• Enterprise: Custom (400 to 1,000+) concurrent requests

See the full pricing table for details. Contact us for tailor-made Enterprise solutions.

If I get a “429 Too Many Requests” error, do I lose that request or is it queued?

You’ll receive an error, and that request won’t be queued or retried automatically. You’ll need to manage retries on your end, ensuring you don’t exceed your concurrency limit.

Can I increase my concurrency limit?

Absolutely! We offer various plans with different concurrency limits to suit your needs. If you find yourself frequently hitting the concurrency limit, consider upgrading.

How can I monitor my concurrency usage?

When using Fetch, each response includes these helpful headers:

• Concurrency-Limit: Shows your maximum concurrent request limit
• Concurrency-Remaining: Shows how many free concurrency slots you have available

I’ve been blocked by repeatedly exceeding my concurrency limit. Why?

Whenever you exceed your plan concurrency limit, you’ll start receiving “429 Too Many Requests” errors. If you keep sending more and more requests exceeding your plan concurrency limit in a short period of time, the service may temporarily block your IP address to prevent API misuse.

The IP address ban will last only a few minutes, but repeatedly being blocked might end in a long-lasting block. Check the concurrency optimization section for more information on how to limit concurrent requests to prevent being blocked.

Troubleshooting with Support

When contacting Zenrows support for any issues with your requests, always include:

1. The X-Request-Id from the response headers
2. The exact error message you received
3. The timestamp of when the error occurred
4. Details about the parameters you used in the request

This information, especially the Request ID, allows our support team to quickly locate your specific request in our logs and provide more effective assistance.

What is Geolocation and What are All the Premium Proxy Countries?

Many websites tailor their content based on the visitor’s location. For example, Amazon displays different products and prices on its UK (.co.uk) and French (.fr) sites. If you’re scraping data from these sites, using a regional IP ensures that you receive the correct localized content. Also some websites restrict access to their content based on geographic location.

To avoid discrepancies caused by regional variations, such as different products being displayed on a retailer’s website, you can send a specific country code with your request. This ensures that your request is localized to the desired country, allowing you to obtain consistent and replicable results.

Zenrows supports proxies from numerous countries around the world. You can use any country’s ISO code to configure your proxies.

Here is the comprehensive list of premium proxy countries supported by Zenrows:

af => Afghanistan
al => Albania
dz => Algeria
ad => Andorra
ao => Angola
ai => Anguilla
ag => Antigua and Barbuda
ar => Argentina
am => Armenia
au => Australia
at => Austria
az => Azerbaijan
bs => Bahamas
bh => Bahrain
bd => Bangladesh
bb => Barbados
by => Belarus
be => Belgium
bz => Belize
bj => Benin
bm => Bermuda
bt => Bhutan
bo => Bolivia, Plurinational State of
ba => Bosnia and Herzegovina
bw => Botswana
br => Brazil
bn => Brunei Darussalam
bg => Bulgaria
bf => Burkina Faso
bi => Burundi
cv => Cabo Verde
kh => Cambodia
cm => Cameroon
ca => Canada
ky => Cayman Islands
cf => Central African Republic
td => Chad
cl => Chile
cn => China
co => Colombia
km => Comoros
cg => Congo
cd => Congo, The Democratic Republic o
cr => Costa Rica
ci => Cote D'ivoire
hr => Croatia
cu => Cuba
cy => Cyprus
cz => Czech Republic
dk => Denmark
dj => Djibouti
do => Dominican Republic
ec => Ecuador
eg => Egypt
sv => El Salvador
gq => Equatorial Guinea
er => Eritrea
ee => Estonia
et => Ethiopia
fo => Faroe Islands
fj => Fiji
fi => Finland
fr => France
gf => French Guiana
pf => French Polynesia
ga => Gabon
gm => Gambia
ge => Georgia
de => Germany
gh => Ghana
gi => Gibraltar
gr => Greece
gl => Greenland
gp => Guadeloupe
gu => Guam
gt => Guatemala
gn => Guinea
gw => Guinea-Bissau
gy => Guyana
ht => Haiti
hn => Honduras
hk => Hong Kong
hu => Hungary
is => Iceland
in => India
id => Indonesia
ir => Iran, Islamic Republic of
iq => Iraq
ie => Ireland
im => Isle of Man
il => Israel
it => Italy
jm => Jamaica
jp => Japan
jo => Jordan
kz => Kazakhstan
ke => Kenya
kr => Korea, Republic of
kw => Kuwait
kg => Kyrgyzstan
la => Lao People's Democratic Republic
lv => Latvia
lb => Lebanon
ls => Lesotho
lr => Liberia
ly => Libya
lt => Lithuania
lu => Luxembourg
mo => Macao
mk => Macedonia, The Former Yugoslav Republic of
mg => Madagascar
mw => Malawi
my => Malaysia
mv => Maldives
ml => Mali
mt => Malta
mq => Martinique
mr => Mauritania
mu => Mauritius
mx => Mexico
md => Moldova, Republic of
mn => Mongolia
me => Montenegro
ma => Morocco
mz => Mozambique
mm => Myanmar
na => Namibia
np => Nepal
nl => Netherlands
nc => New Caledonia
nz => New Zealand
ni => Nicaragua
ne => Niger
ng => Nigeria
no => Norway
om => Oman
pk => Pakistan
ps => Palestine, State of
pa => Panama
pg => Papua New Guinea
py => Paraguay
pe => Peru
ph => Philippines
pl => Poland
pt => Portugal
pr => Puerto Rico
qa => Qatar
re => Reunion
ro => Romania
ru => Russia
rw => Rwanda
lc => Saint Lucia
mf => Saint Martin (French Part)
ws => Samoa
sa => Saudi Arabia
sn => Senegal
rs => Serbia
sc => Seychelles
sl => Sierra Leone
sg => Singapore
sx => Sint Maarten (Dutch Part)
sk => Slovakia
si => Slovenia
sb => Solomon Islands
so => Somalia
za => South Africa
ss => South Sudan
es => Spain
lk => Sri Lanka
sd => Sudan
sr => Suriname
sz => Swaziland
se => Sweden
ch => Switzerland
sy => Syrian Arab Republic
tw => Taiwan, Province of China
tj => Tajikistan
tz => Tanzania, United Republic of
th => Thailand
tl => Timor-Leste
tg => Togo
to => Tonga
tt => Trinidad and Tobago
tn => Tunisia
tr => Turkey
tm => Turkmenistan
ug => Uganda
ua => Ukraine
ae => United Arab Emirates
gb => United Kingdom
us => United States
uy => Uruguay
uz => Uzbekistan
vu => Vanuatu
ve => Venezuela, Bolivarian Republic of
vn => Viet Nam
ye => Yemen
zm => Zambia
zw => Zimbabwe

How to use it with each product:

Fetch

Incorporate the selected ISO code into your scraping script to route your requests through the chosen proxy.

scraper.py

# pip install requests
import requests

# Example for setting a proxy for Canada
params = {
    'premium_proxy': 'true',
    'proxy_country': 'ca',
}

response = requests.get('https://api.zenrows.com/v1/', params=params)
print(response.text)

Residential Proxies

Zenrows supports IPs from a wide variety of countries, allowing you to access geo-restricted data with ease. You can specify a country by using country followed by the country code in your proxy URL.

Example for Spain:

http://<YOUR_USERNAME>:<YOUR_PASSWORD>[e-mail]:1337

Browser Sessions

You basically have two ways to set a country geolocation on Browser Sessions, depending if you’re using the SDK or not.

Without using the SDK, select a specific country by adding the proxy_country parameter to the WebSocket URL:

wss://browser.zenrows.com?apikey=YOUR_ZENROWS_API_KEY&proxy_country=es

In SDK mode, specify the country when generating the connection URL:

const connectionURL = scrapingBrowser.getConnectURL({
    proxy: {
        location: ProxyCountry.ES
    },
});

By using the right proxy, you can ensure more reliable and geographically relevant data scraping while maintaining compliance with website policies.

For further assistance or more detailed configuration, refer to the Zenrows documentation or contact their support team. Happy scraping!

Do you charge failed requests using Fetch?

Not at all. We only charge for successful requests :)

404 Not Found and 410 Gone errors are charged

I need to scrape millions of websites every month. Is it possible?

You can extract data from as many websites as you want. Throw us 1M requests or 50M; we can perfectly handle it!

Do I need to install anything to use the product?

Not at all. Our infrastructure is cloud-based, making our language-agnostic API easy and seamless to use.

Do you rotate IPs on every request?

Yes, each new request automatically uses a different IP to ensure anonymity and avoid detection.

However, if you need to maintain the same IP for a specific period, this is also possible. Please refer to each primitive’s documentation for detailed information on how to configure it.

Can I use Residential Proxies with my custom scraping tools?

Absolutely. Residential Proxies are designed to integrate seamlessly with any custom scraping setup, regardless of the tools or frameworks you use.

Do you return the fingerprints from the scraping process?

No, our fingerprints are not returned.

Do you return the page's IP or my own IP during scraping?

No, we do not return either the page’s IP or our own IP.

Can I access the page headers during scraping?

No, you cannot access the page headers directly. However, you can access the response headers.

Do you return CAPTCHA tokens after bypassing them?

No, CAPTCHA tokens are not returned after bypassing.

Do you offer custom coding solutions?

No, we provide the tools for scraping, but you need to develop your own solutions.

We also offer No-Code options for those who prefer to avoid coding.