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06 Numbers and Powers

Web Scraping Proxy Services by Workload

Card No. 06·37872 · Updated · Standard formula, shown below

Total time needed 5.56 hours
Required throughput
1.16 requests/sec
Result
Daily scrape volume (requests)
100000 requests/day
You entered
Average request duration
2 seconds
You entered
You enter
Daily scrape volume (requests), Average request duration, Simultaneous connections
You get
Total time needed, Required throughput
Rounding
2 dp

Web scraping proxy services data teams should evaluate by matching the proxy type to the workload: residential proxies for large-scale, anti-bot-heavy sites; datacenter proxies for high-speed, low-cost scraping of less protected sites; and mobile proxies for app-based or highly restricted targets. The right choice depends on volume, target site defenses, geographic needs, and budget.

Formula

The calculator estimates the total time to complete a scraping job and the required throughput, based on daily volume, average request duration, and the number of simultaneous connections.

Total time (hours) = (daily requests × average request duration in seconds) / (simultaneous connections × 3600)

Throughput (requests per second) = daily requests / 86400 (seconds per day)

Variables:

  • t – daily scrape volume (requests per day)
  • d – average request duration (seconds, including network latency and server response time)
  • c – simultaneous connections (how many requests your scraper can run in parallel)

Worked Example

Using the default values: t = 100,000 requests/day, d = 2 seconds, c = 10 connections.

Total time = (100,000 × 2) / (10 × 3600) = 200,000 / 36,000 = 5.56 hours.

Throughput = 100,000 / 86,400 = 1.16 requests per second.

So with 10 parallel connections, the job finishes in about 5.6 hours. If you need it done in 1 hour, you would need roughly 56 connections (200,000 / 3600).

Why Workload Matters

Proxy services are not one-size-fits-all. A small team scraping a few thousand pages a day for a price comparison site has different needs than a large operation collecting millions of product listings daily. The workload determines:

  • How many IP addresses you need (to avoid rate limits)
  • Whether you need rotating IPs or static ones
  • Whether residential, datacenter, or mobile proxies are cost-effective
  • How much concurrency your infrastructure can support

Data teams often underestimate the volume of requests a real scrape generates. A single product page might require multiple requests: HTML, images, API calls, and AJAX endpoints. A site with 10,000 products could easily produce 50,000 requests. Knowing your daily request count is the first step in evaluating any proxy provider.

Proxy Types and Their Workload Fit

There are three main categories of proxies used in web scraping:

  • Datacenter proxies – IPs hosted on servers in data centers. They are fast, cheap, and abundant. Best for high-volume scraping of sites with weak anti-bot protections. They are often blocked by sophisticated sites like Google or Amazon.
  • Residential proxies – IPs assigned by ISPs to homeowners. They appear as real user traffic, making them harder to block. Ideal for scraping sites with aggressive anti-bot measures, but they are slower and significantly more expensive.
  • Mobile proxies – IPs from mobile carriers. Extremely trusted by websites, but also the most expensive and slowest. Used for app scraping, ad verification, and sneaker copping.

Workload dictates which type you choose. For a low-volume scrape of a site that blocks datacenter IPs, residential is necessary. For high-volume scraping of a site that doesn’t block datacenter IPs, using residential would waste money. Many teams use a mix: datacenter for initial discovery, residential for retries after blocks.

Key Metrics to Compare

When evaluating proxy services, look at these metrics:

  • Success rate – Percentage of requests that return the desired data without errors. Aim for 95%+.
  • Speed – Average response time. Residential proxies typically have higher latency (1-3 seconds) than datacenter (50-200 ms).
  • Rotation options – Whether you can rotate IPs per request, per session, or keep sticky sessions.
  • Geographic targeting – Ability to choose country, city, or even ASN.
  • Bandwidth vs. requests pricing – Some providers charge per GB, others per request. For HTML scraping, requests-based is often cheaper; for large file downloads, bandwidth-based is better.
  • Concurrency limits – Maximum number of simultaneous connections allowed. This directly affects throughput.

Data teams should run a small pilot test with each candidate provider, sending a few thousand requests to the target site, and measure success rate and speed. Don’t rely on provider marketing numbers.

Cost Considerations

Proxy costs vary widely. Datacenter proxies can cost as little as $1 per GB, while residential proxies often range from $5 to $15 per GB. Mobile proxies can be $20+ per GB. For a workload of 1 million requests per day, residential proxies could cost thousands of dollars monthly, while datacenter might be a few hundred.

To estimate cost, calculate your average request size. A typical HTML page is 1-2 MB. If you scrape 1 million pages, that’s 1-2 TB of bandwidth. At $10/GB residential, that’s $10,000-$20,000 per month. Many teams reduce costs by:

  • Caching responses to avoid re-scraping
  • Using datacenter proxies for initial fetches and residential only for blocked requests
  • Compressing responses (gzip) to reduce bandwidth
  • Scraping during off-peak hours to reduce contention

Common Pitfalls

Data teams often make these mistakes when evaluating proxies:

  • Ignoring retry logic – A proxy service with 95% success rate might still require retries for 5% of requests. Ensure your scraper handles retries with exponential backoff.
  • Overlooking IP rotation frequency – Some sites track IPs across sessions. If you rotate too often, you might get blocked; if too rarely, you might get rate-limited.
  • Not testing from the target’s perspective – A proxy that works for one site may fail on another due to different anti-bot systems (Cloudflare, Akamai, etc.).
  • Underestimating session management – Some sites require the same IP for a login session. Sticky sessions are essential for such workloads.

Alternatives to Proxies

Sometimes proxies are not the best solution. Consider these alternatives:

  • API access – If the site offers an official API, use it. It’s more stable and legal.
  • Headless browsers with built-in rotation – Tools like Puppeteer or Playwright can rotate user agents and use browser fingerprints, but they are slower and more resource-intensive.
  • Scraping as a service – Services like ScrapingBee or Zyte handle proxies and rendering for you, but you pay per API call.
  • Open data sources – Some data is available via public datasets or government portals, avoiding scraping altogether.

Frequently Asked Questions

What is the difference between rotating and static proxies?

Rotating proxies assign a new IP for each request or every few minutes, which helps avoid rate limits. Static proxies keep the same IP for a longer session, which is useful when you need to maintain a login session or when the target site expects consistent behavior. For high-volume scraping, rotation is usually preferred, but for tasks like account creation, static might be necessary.

How many IPs do I need for my workload?

There’s no fixed number. It depends on the target site’s rate limits and your concurrency. A simple formula: if you need 100 requests per second and each IP can handle 5 requests per second without being blocked, you need at least 20 IPs. But you should always start with a small pool and increase based on observed block rates.

Can I use free proxies for scraping?

Free proxies are generally unreliable and often slow or malicious. They are frequently blocked by websites and may log your traffic. For any serious data collection, paid proxies are recommended. Free proxies might work for very low-volume, non-sensitive scraping, but they are not suitable for production workloads.

How do I measure proxy success rate?

Run a test by sending a sample of requests (e.g., 1,000) through the proxy to the target site. Count the responses that return the expected data without errors (HTTP 200 with valid content). Divide by total requests. Also measure the time taken and the number of CAPTCHAs or blocks encountered.

What is the best proxy type for scraping Google?

Google is heavily protected and blocks most datacenter IPs. Residential proxies are often required, but even they can be detected if used too aggressively. Many teams use specialized search engine scraping APIs or rely on Google’s Custom Search JSON API. If you must scrape, use residential proxies with low concurrency and random delays.

Is web scraping with proxies legal?

Legality depends on the website’s terms of service and local laws. Scraping public data for personal use is often considered legal, but scraping behind login or bypassing CAPTCHAs may violate terms. Always review the site’s robots.txt and terms of service. When in doubt, consult a legal professional. Proxies do not make scraping legal; they only hide your IP.

Related

Formula used
in t | Daily scrape volume (requests) | requests/day | 100000 | 0 | 10000000
in d | Average request duration | seconds | 2 | 0 | 60
in c | Simultaneous connections | - | 10 | 1 | 1000
out total_time | Total time needed | hours | (t * d / c) / 3600 | 2
out req_per_sec | Required throughput | requests/sec | t / 86400 | 2

Each line is one input (in, sel, list) or one result (out: label, unit, formula, decimals). How the calculators work

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.

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