How to check a website's performance through a proxy

Imagine this: you launch a new landing page, but users from other countries complain that the site is unavailable, or your monitoring service suddenly starts showing strange errors. How can you understand whether the problem is on your side, on the host’s side, or in the network of a specific region? This is where a proxy comes in. Checking how a website works through a proxy allows you to “simulate” the site’s behavior under different conditions: from another IP, from another country, through a corporate firewall, or through a mobile network.

What a proxy is

A proxy is simply an intermediate server: your client (browser or app) sends a request to the proxy, and the proxy forwards it to the destination site and returns the response. Essentially, a proxy “represents” you on the network: it can hide your real IP, cache pages, or filter traffic.

Types of proxies

There are four main types of proxy protocols, and it’s convenient to explain them based on what they can do.

• An HTTP proxy works directly with HTTP requests. It “sees” headers and page content, so it’s well suited for web traffic, caching, and filtering, but it doesn’t work for arbitrary applications and is unsafe for sensitive data unless the connection is encrypted.
• An HTTPS proxy essentially does the same thing but can tunnel encrypted TLS traffic using the CONNECT command. Inside the tunnel, data remains encrypted and the proxy cannot see the content, which makes it safer for working with HTTPS websites.
• SOCKS4 is a more “low-level” proxy. It forwards any TCP connections and doesn’t parse HTTP, making it suitable for SSH, FTP, and games, but it doesn’t support UDP and typically lacks built-in authentication.
• SOCKS5 is an improved version of SOCKS4. It supports authentication, UDP, and IPv6, making it the most versatile option for applications that need both TCP and UDP.

Why check website performance through a proxy

• You check a website through a proxy to see how the service behaves not only from your own network but also from specific geographic points and connection types. Sometimes a site opens fine in your office, but from another country access is blocked by geolocation, a CDN returns outdated cache, or ISPs route traffic in a way that causes timeouts — proxies help reproduce such conditions and pinpoint where the problem lies.

• Proxies make it convenient to check localization and personalization. Content, redirects, Accept-Language headers, and cookies may differ depending on IP or region, which is important for testing A/B experiments, language versions, and localized promotions.

• Checking through a proxy also helps identify errors in IP-based logic (for example, different versions of pages for mobile carriers or corporate networks) and determine whether the site or service is being blocked by an external protection system (WAF, antibot tools, geofencing).

• Proxies allow you to test behavior on different types of networks: mobile, residential, and data center — each has different routing, latency, and packet loss characteristics. This matters not only for load speed but also for the correct functioning of websockets, media delivery, or timeout-sensitive operations.

• Proxies make it easier to diagnose SSL/TLS issues, because certificate visibility and intermediate nodes can differ from different network points.

• You cannot forget about security and compliance. When testing via third-party proxies, it’s important to consider that traffic may be logged or modified, so for sensitive operations it’s better to use trusted or self-managed access points.

What to check

When testing a site through a proxy, it’s important to examine not just whether it “opens or not,” but how the site looks and behaves for a real user in the given network and region. What exactly should you check and why?

Interface

Make sure the page renders correctly: layout isn’t broken, fonts and images load, and interactive elements (buttons, forms, modals) are clickable and functional. Check responsiveness — display on mobile and desktop sizes — and visual differences for different locales (languages can affect text wrapping and button lengths). Pay attention to browser console errors (JavaScript), because scripts may fail due to timeouts or resource blocks caused by network conditions.

Prices and commercial content

Check price display, currency, and tax calculations: prices may differ by region, so ensure that price, currency, and formatting (comma/period) are correct. Verify that discounts or promo codes apply, and that local payment methods and their settings appear. Missing prices or incorrect currency conversion are often linked to APIs, CDNs, or geo-dependent logic, so test the entire checkout flow — from selecting an item to reaching the payment page.

Content and localization

Check text blocks, translations, images, and localized banners. Ensure that redirects to language subdomains/paths work correctly, and that meta tags, Open Graph, and hreflang are correct for target regions. Also check personalized content (recommendations, A/B campaigns) — sometimes it is shown only to specific geographic segments.

Availability and network behavior

Check whether access is blocked by a WAF/antibot mechanism or geoblocking. Also verify SSL/TLS: certificate chain validity, SNI correctness, and any errors during TLS handshake.

Load speed and user experience

Measure the time to load main content, the full page load time, and the load speed of critical resources (CSS, JS, images). Evaluate how the CDN serves resources in the target region: files might be outdated (stale cache). Test lazy loading, preloads — with a slow connection some elements might not appear in time.

Preparing to test a website

Choosing the right proxy

Before testing, think about what exactly you want to check: page availability, content localization, checkout process, or load speed. Prepare a couple of URLs and simple scenarios — for example: open the home page, log in, add an item to the cart, and proceed to checkout (without real payment data).

For web pages, it’s convenient to use HTTP/HTTPS proxies — they are easy to configure in a browser. If you need to test non-standard applications or UDP traffic, choose SOCKS5. To check regional behavior, pick proxies in the required country (residential or mobile IPs simulate real users better than data centers).

Checking proxy relevance and functionality

1. Make sure the proxy works: open a simple site through it and verify that the external IP changed and the page loads.

2. Perform several consecutive requests: test latency, connection stability, and correct redirects. Ensure the proxy doesn’t insert banners or headers and that cookies/sessions work properly when navigating the site.

3. Do not send passwords or payment data through third-party proxies. Record which proxy you used, the time of the test, and any noticeable errors — this will help reproduce and fix the issue quickly.

What to pay attention to during testing

• First check whether the page opens and what the server returns, and whether redirects work correctly. This is visible from HTTP headers and from how the browser or your application handles transitions.

• Check how the site looks and behaves. Do layout, fonts, and images load? Do buttons, forms, and scripts work? Sometimes the server responds correctly, but due to blocked resources or timeouts, JavaScript doesn’t execute and the interface appears broken.

• Make sure localization and commercial elements are correct: do local prices, currency, texts, and promo banners appear? Are discounts applied properly? Are payment methods available? Errors in geo-dependent logic often show up here.

• Sessions and cookies matter. Check whether logins persist and whether cookies are preserved across pages. For payment and authentication scenarios, use only trusted proxies.

• Pay attention to website protection. Geoblocks, WAF, or antibot systems may return CAPTCHA or 403 errors for traffic from some proxies — the issue may not be with the site itself. If you see a CAPTCHA or block, it may be a protection policy.

• Check proxy stability. Perform several consecutive requests to ensure that the connection doesn’t drop.

Where to buy high-quality proxies for testing

• High-quality proxies can be obtained from reputable commercial providers, specialized services, and aggregators that offer a wide selection of locations and types.
• When choosing, pay attention to stability, speed, availability of required locations, protocol support (HTTP(S)/SOCKS5), limits on simultaneous connections, logging policy, and DNS-over-proxy support.

For reliable website behavior testing, it’s better to use paid, trusted providers. Belurk offers proxies with different address types and geographic targeting, supports HTTP(S) and SOCKS, and provides a convenient control panel and API for test automation.

Geotargeting, different types of proxies, management, and automation help quickly detect and reproduce issues that real users encounter. Belurk is a convenient and practical choice for such tasks.