Peter Hansen
Posted on May 5, 2020
The Ultimate Guide to Proxies for Web Scraping
Proxy management is the most crucial component of any web scraping project. Those serious about web scraping know that using proxies is mandatory when scraping the web at any reasonable scale. It often happens, that proxy issue management and troubleshooting actually take more time than creating and maintaining the web scrapers themselves. In this detailed guide, you will be able to know the differences between the main proxy options as well as the factors that should be considered when picking a proxy solution for your project or business.
Contents:
- What is a proxy? Why it is needed when web scraping?
- Why proxies are important for web scraping?
- Why prefer a proxy pool?
- Which is the best proxy solution for you?
- Public, shared, or dedicated proxies?
- How you can manage your proxy pool?
- Do It Yourself
- Proxy Rotators
What is a proxy? Why it is needed when web scraping?
Before explaining what proxies are, let’s understand what an IP address is and how it works. Giving each device a unique identity, an IP address is a numerical address allocated to every device that has a connection with an Internet Protocol network like the internet. An IP address usually looks like this: 199.125.7.315.
A proxy server works as a middle man between a client and a server. It takes a request from the client and redirects it to the target server. Using a proxy gives you the ability to scrape the web anonymously if you want to. The website you are making the request to is unable to see your IP address but the IP address of the proxy.
The world has transitioned to a newer standard called IPv6 from IPv4 at present. The creation of more IP addresses will be allowed by this newer version. Although, IPv6 has still not gained immense acceptance in the proxy business. Thus, the IPv4 standard is still mostly used by IPs.
Using a third-party proxy is recommended while scraping a website. In case your scraping is overburdening their servers or if they would like you to stop scraping the data displayed on their website, you should set your company name as the “User-Agent” HTTP header so the website owner can contact you.
Why proxies are important for web scraping?
- Making unlimited concurrent sessions on the same or different websites is possible by using proxies.
- If you want to make a higher volume of requests to a target website without being banned, then using a proxy pool serves the purpose.
- Using a proxy or especially a pool of proxies noticeably diminishes the chances that your spider will get banned or blocked. Thus, it offers a reliable website crawling experience.
- Proxy usage allowing you to bypass/avoid IP bans/blocks. Websites very often block requests from AWS due to malicious actors overloading websites having large volumes of requests using AWS servers
- Proxies making it possible to send your request from a specific geographical location. This makes it possible for you to see the precise content that the website displays for that given location or device. When scraping product data from online retailers, this becomes extremely significant.
Why prefer a proxy pool?
Using a single proxy for website scrapping is not recommended because it results in the reduction of your crawling reliability, geotargeting options, and the number of concurrent requests you can make. That’s why building a pool of proxies is required that you can route your requests through while breaking the total traffic over a large number of proxies.
There are various factors on which depend the size of your proxy. They have a huge impact on the effectiveness of your proxy pool. These are mentioned below:
- Number of requests you will be making every hour
- Type of IPs used by you as proxies - datacenter, residential or mobile IPs
- The complexity of the proxy management approach - proxy rotation, throttling, session administration, etc.
- Target websites - bigger websites have better measures against programmatic web scrapping which requires a larger proxy pool.
- Quality of the IPs being used as proxies - public proxies, shared or private dedicated proxies, datacenter, residential or mobile IPs. Due to the nature of the network, data center IPs are sometimes more stable than residential/mobile IPs but typically lower quality than residential IPs and mobile IPs.
If the configuration of your proxy pool for your specific web scraping project is not done properly, then your proxies may get blocked sometimes and you will not be able to access the target website.
Which is the best proxy solution for you?
Selecting the best proxy option is not an easy task at all. Every proxy provider is claiming that they have the best proxy IPs on the web without telling you exactly why. You need to analyze which is the best proxy solution for your particular project.
In this section, let’s discuss the different types of IPs that can be used as proxies and which one is suited for your needs.
First, let’s discuss the fundamentals of proxies - the underlying IP’s. There are three main types of IPs to choose from and each type has its own pros and cons.
Datacenter IPs
The most common type, these are the IPs of servers housed in data centers. These are the cheapest to buy. A very robust web crawling solution can be built for your business with the right proxy management solution.
Residential IPs
Enabling you to route your request through a residential network, these IPs are tougher to obtain and are expensive. However, it is also true that there are situations wherein you could easily achieve the same results with cheaper datacenter IPs. Legal/consent issues are also raised as you are using a person’s personal network for web scrapping.
Mobile IPs
These are the IPs of private mobile devices. These are very expensive because acquiring the IPs of mobile devices is very hard. For the majority of web scraping tasks, mobile IPs are excessive measures unless you intend to just scrape the results displayed to mobile users. Additionally, the result of mobile IP can raise more legal/consent issues because sometimes, the device owner is not completely aware that you are using their GSM network for web scraping.
Datacenter IPs are recommended for most of the cases. Along with that, you should put in place a robust proxy management solution. This is a good option if you want the best results at the lowest cost. These IPs give similar results as residential or mobile IPs without the legal concerns and at a fraction of the cost if there is proper proxy management.
Public, shared, or dedicated proxies?
Whether you should use public, shared or dedicated proxies are also very important to discuss before you pick the right option.
Staying clear of public proxies or open proxies is a general rule. These are of very low quality and can be dangerous as well. Anyone can use these proxies and thus, they quickly get used to slam websites with huge amounts of dubious requests. As a result, they get blacklisted and blocked by websites very quickly. They are often infected with malware and other viruses as well. Therefore, using a public proxy would mean running the risk of spreading any present malware, infecting your own machines, and even making public your web scraping activities in case you haven't properly configured your security (SSL certificates, etc.).
Deciding between a shared and dedicated proxy is a bit difficult. Your need for performance and your budget using a service where you pay for access to a shared pool of IPs might be the right option for you, depending on the size of your project. Paying for a dedicated pool of proxies might be the better option for you if you have a big budget and when the performance is of high priority.
Picking the right type of proxy is only the tip of the iceberg. Managing your pool of proxies so they don’t get banned is the real tricky part.
How you can manage your proxy pool?
Purchasing a pool of proxies and routing your requests via them is not a long-term solution if you want to on scrape at any reasonable scale. Inevitably, your proxies will be banned and stop returning high-quality data.
Below mentioned are the major challenges that you will face while managing a proxy pool:
- User-Agents- Managing user agents is important for having a healthy crawl.
- Using Delays- Creating random delays and applying a smart throttling system to help hide the fact that you are scraping.
- Retry Errors- Your proxies need to be able to retry the request with different proxies in case they experience any errors, bans, timeouts, etc.
- Geographical Targeting- To make sure that only some proxies will be used on certain websites, you will be required to configure your pool sometimes.
- Control Proxies- There is a requirement by some scraping proxies that you keep a session with the same proxy. Thus, you should configure your proxy pool to allow for this.
- Identify Bans- Detection of numerous types of bans is a very important responsibility of your proxy solution so that you can troubleshoot and fix the underlying problem, i.e. captchas, redirects, blocks, ghosting, etc.
Managing a pool of proxies in 100s or 1000s is a very tough task. You have three chief solutions to overcome these problems- Do It Yourself, Proxy Rotators, and Done For You Solutions.
Do It Yourself
Purchasing a pool of shared or dedicated proxies along with building and tweaking a proxy management solution is to be done by you in this situation for overcoming all the challenges you run into. This is a cheap option but consumes a lot of time and resources. This method should only be chosen if you have a devoted web scraping team that can manage your proxy pool, or you don’t have the required budget and can’t afford anything better.
Proxy Rotators
You can also purchase your proxies from a provider that also provides proxy rotation and geographical targeting. The more basic proxy management issues are taken care of in this situation. With this, you can develop and manage session management, throttling, ban identification logic, etc.
How to pick the best proxy solution for your project?
Deciding on an approach to building and managing your proxy pool is not an easy task. While deciding on the best proxy solution for your needs, there are some important questions that you should ask yourself:
How much can you spend?
Managing your own proxy pool is going to be the cheapest option in case you have a very limited or virtually non-existent budget. But you should consider outsourcing your proxy management if you even have a small budget. This way, you will get an effective solution that manages everything.
What is your top priority?
Buying your own pool of proxies and managing them yourself is the best option when your number one priority is to know everything about proxies and web scrapping. But like most of the companies, if you are aiming to get the web data and achieve maximum performance from your web scraping, then it’s better to outsource your proxy management. At the very least, you can use a proxy rotator.
What are your available resources and technical skills?
If you want to manage your own proxy pool for a reasonable size web scraping project, then you should have a basic level of software development knowledge and bandwidth for building and maintaining your spiders’ proxy management logic. If you neither have the required expertise or the bandwidth, then you should use a proxy rotator and build your own proxy management infrastructure.
Answering these questions will help you in deciding which approach to proxy management suits your needs in the best possible way.
Build in-house or done for your solutions?
Buying access to a shared pool of IPs and managing the proxy management logic yourself is probably your best option if your focus is on learning all about web scraping. This is also the most suitable choice if you have budget constraints. However, you should consider using either a proxy rotator and building the other management infrastructure in-house or a done for you proxy management solution if you are targeting on having the needed web data with no hassle or maximizing your web scraping performance.
Proxy providers
A proxy provider offering proxy rotation as a service should be used if you are willing to do it on your own. The first layer of managing your proxies will be removed with this. Please note, that you still would like to create a mechanism to manage sessions, throttle HTTP requests in order to prevent IP bans/blocks.
Here you can find a list with best residential proxy providers.
Proxy services
If you are begginer and don't want to want to spend time for proxy management, however you still need to proxy your request - you can user proxy services.
Proxy services manages a huge pool of proxies, carefully rotating, throttling, blacklists, and selecting the optimal IPs to use for any individual request to give the optimal results at a minimal cost. Thus, the hassle of managing IPs is removed completely. Users can focus on the data, not proxies.
Take for example Proxybot service. You simply need to send a request to Proxybot API and it will proxy your HTTP request and send you a response from yor target server.
https://proxybot.io/api/v1/{API_KEY}?url={YOU_TARGET_URL}
What are the legal considerations when using proxies?
When it comes to web scraping and proxies, you should also be aware of the legal considerations. Using a proxy IP to visit a website is legal. Although, there are some points that you need to keep in mind in order to make sure you don't stray into a grey area.
With the ability to make a huge volume of requests to a website without the website being easily able to identify you, people can get greedy and overload a website’s servers with too many requests. This is never the right thing to do.
You should always be respectful to the websites you scrape if you are a web scraper. You should always comply with web scraping best practices in order to make sure that your spiders cause no harm to the websites you are scraping. You should limit your requests or stop scraping if the website informs that your scraping is burdening their site or is unwanted. You will not run into any legal matters as long as you are ethical.
The other legal consideration you should give importance when using residential or mobile IPs is whether you have the IPs owners’ explicit consent to use their IP for web scraping or not. This is stated in our Web Scrapers Guide to GDPR.
You should make sure that the residential IP’s owner has given an open consent for their home or mobile IP to be used as a web scraping proxy.
You will be required to handle this consent yourself in case you have your own residential IPs. Although, if you have decided to obtain residential proxies from a third-party provider, then before using the proxy for your web scraping project, you should make sure that they have got consent and are in compliance with GDPR.
Posted on May 5, 2020
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