Connect with us


What is Robots.txt File? What are the Different types of bots or Web Crawlers?

Robots.txt is a standard text file is used for websites or web applications to communicate with web crawlers (bots). It is used for the purpose of web indexing or spidering. It will help the website that ranks as highly as possible by the search engines.





1. What is robots.txt?

Robots.txt is a standard text file that is used for websites or web applications to communicate with web crawlers (bots). It is used for web indexing or spidering. It will help the site that ranks as highly as possible by the search engines.

The robots.txt file is an integral part of the Robots Exclusion Protocol (REP) or Robots Exclusion Standard, a robot exclusion standard that regulates how robots will crawl the web pages, index, and serve that web content up to users.

Web Crawlers

Web Crawlers are also known as Web Spiders, Web Robots, WWW Robots, Web Scrapers, Web Wanderers, Bots, Internet Bots, Spiders, user-agents, Browsers. One of the most preferred Web Crawler is Googlebot. This Web Crawlers are simply called as Bots.

The largest use of bots is in web spidering, in which an automated script fetches, analyzes, and files information from web servers at many times the speed of a human. More than half of all web traffic is made up of bots.

Many popular programming languages are used to created web robots. The Chicken Scheme, Common Lisp, Haskell, C, C++, Java, C#, Perl, PHP, Python, and Ruby programming languages all have libraries available for creating web robots. Pywikipedia (Python Wikipedia bot Framework) is a collection of tools developed specifically for creating web robots.

Examples of programming languages based open-source Web Crawlers are

  • Apache Nutch (Java)
  • PHP-Crawler (PHP)
  • HTTrack (C-lang)
  • Heritrix (Java)
  • Octoparse (MS.NET and C#)
  • Xapian (C++)
  • Scrappy (Python)
  • Sphinx (C++)

2. Different Types of Bots

a) Social bots

Social Bots have a set of algorithms that will take the repetitive set of instructions in order to establish a service or connection works among social networking users.

b) Commercial Bots

The Commercial Bot algorithms have set off instructions in order to deal with automated trading functions, Auction websites, and eCommerce websites, etc.

c) Malicious (spam) Bots

The Malicious Bot algorithms have instructions to operate an automated attack on networked computers, such as a denial-of-service (DDoS) attacks by a botnet. A spambot is an internet bot that attempts to spam large amounts of content on the Internet, usually adding advertising links. More than 94.2% of websites have experienced a bot attack.

d) Helpful Bots

The bots will helpful for all customers and companies and make Communication over all the Internet without having to communicate with a person. for example, e-mails, chatbots, and reminders, etc.

Different Types of Bots

3. List of Web Crawlers or User-agents

List of Top Good Bots or Crawlers or User-agents

Google Mobile Adsense
Google Plus Share
Google Feedfetcher
Bingbot Mobile
Sogou Spider
Facebook External Hit
Soso Spider

List of Top Bad Bots or Crawlers or User-agents

Web Downloader
HTTrack Website Copier/3.x
Black Hole
Crescent Internet ToolPak HTTP OLE Control v.1.0

Note:- If you need more names of Bad Bots or Crawlers or User-agents with examples in the TwinzTech Robots.txt File.

4. Basic format of robots.txt

User-agent: [user-agent name]
Disallow: [URL string not to be crawled]

The above two lines are considered as a complete robots.txt file. one robots file can contain multiple lines of user agents names and directives (i.e., allows, disallows, crawl-delays, and sitemaps, etc.)

It has multiple sets of lines of user agent’s names and directives, which are separated by a line break for an example in the below screenshot.

user-agent are separated by a line break and its Comment

Use # symbol to give single line comments in robots.txt file.

5. Basic robots.txt examples

Here are some regular robots.txt Configuration explained in detail below.

Allow full access

User-agent: *


User-agent: *
Allow: /

Block all access

User-agent: *
Disallow: /

Block one folder

User-agent: *
Disallow: /folder-name/

Block one file or page

User-agent: *
Disallow: /page-name.html/

6. How to create a robots.txt file

Robots files are in text format we can save as text (.txt) Formats like robots.txt in editors or environments. See the example in the below screenshot.

robots file save as in .txt formats

7. Where we can place or find the robots.txt file

The website owner wishes to give instructions to web robots. They place a text file called robots.txt in the root directory of the webserver. (e.g.,

This text file contains the instructions in a specific format (see examples below). Robots that choose to follow the instructions try to fetch this file and read the instructions before fetching any other file from the website. If this File doesn’t exist, web robots assume that the web owner wishes to provide no specific instructions and crawl the entire site.

8. How to check my website robots.txt on the web browser

Go to web browsers and enter the domain name in the address bar of the browser and add forward slash like /robots.txt and enter and see the file details ( See the example in the below screenshot.

check website robots.txt on the web browser

9. Where we can submit a robots.txt on Google Webmasters (search console)

Follow the below example screenshots and submit the robots.txt on webmasters (search console).

1. Add a new site property on search console-like as below screenshot (if you have a property on search console leave the first point and move to second).

submiting robots.txt on google search console

2. Click your site property and see the new options on screen and select the crawl options on the left side is as shown in the below screenshot.

submiting robots.txt on google search console

3. Click the robots.txt tester option in crawl options is as shown in the below screenshot.

submiting robots.txt on google search console

4. After clicking the robots.txt tester option in crawl options, we can see the new options on screen and click the submit button is as shown in the below screenshot.

submiting robots.txt on google search console

10. Examples of how to block specific web crawler from a specific page/folder

User-agent: Bingbot
Disallow: /example-page/
Disallow: /example-subfolder-name/

The above syntax tells only Bing crawler (user-agent name Bingbot) not to crawl the page that contains the URL string and not to crawl any pages that contain the URL string

11. How to allow and disallow a specific web crawler in robots.txt

# Allowed User Agents
User-agent: rogerbot
Allow: /

The above syntax tells to Allow the user-agent name called rogerbot for crawling/reading the pages on the website.

# Disallowed User Agents
User-agent: dotbot
Disallow: /

The above syntax tells to Disallow the user-agent name called dot bot for not crawling/reading the pages on the website.

12. How To Block Unwanted Bots From a Website By Using robots.txt File

Due to security we can avoid or block unwanted bots using the robots.txt file. The List of unwanted bots is blocking by the help of robots.txt File.

# Disallowed User Agents

User-agent: dotbot
Disallow: /

User-agent: HTTrack Website Copier/3.x
Disallow: /

User-agent: Teleport
Disallow: /

User-agent: EmailCollector
Disallow: /

User-agent: WebZIP
Disallow: /

User-agent: WebCopier
Disallow: /

User-agent: Leech
Disallow: /

User-agent: WebSnake

The above syntax tells to Disallow the unwanted bots or user-agents names for not crawling/reading the pages on the website.

See the below screenshot with examples

Disallow the unwanted bots

13. How to add Crawl-Delay in robots.txt file

In the robots.txt file, we can set Crawl-Delay for specific or all bots or user-agents

User-agent: Baiduspider
Crawl-delay: 6

The above syntax tells Baiduspider should wait for 6 MSC before crawling each page.

User-agent: *
Crawl-delay: 6

The above syntax tells all user-agents should wait for 6 MSC before crawling each page.

14. How to add multiple sitemaps in robots.txt file

The examples of adding multiple sitemaps in the robots.txt file are


The above syntax tells us to call out multiple sitemaps in the robots.txt File.

15. Technical syntax of robots.txt

There are five most common terms come across in a robots file. The syntax of robots.txt files includes:

User-agent: The command specifies the name of a web crawler or user-agents.

Disallow: The command giving crawl instructions (usually a search engines) to tell a user-agent not to crawl the page or URL. Only one “Disallow:” line is allowed for each URL.

Allow: The command giving crawl instructions (usually a search engines) to tell a user-agent to crawl the page or URL. It is only applicable for Googlebot.

Crawl-delay: The command should tell how many milliseconds a crawler (usually a search engines) should wait before loading and crawling page content.

Note: that Googlebot does not acknowledge this command, but crawl rate can be set in Google Search Console.

Sitemap: The command is Used to call out the location of any XML sitemaps associated with this URL.

Note: This command is only supported by Google, Ask, Bing, and Yahoo search engines.


Here we can see the Robots.txt Specifications.

Also Read : How to Flush the Rewrite URL’s or permalinks in WordPress Dashboard?

16. Pattern-matching in robots.txt file

All search engines support regular expressions that can be used to identify pages or subfolders that an SEO wants excluded.

With the help of Pattern-matching in the robots.txt File, we can control the bots by the two characters are the asterisk (*) and the dollar sign ($).

1. An asterisk (*) is a wildcard that represents the sequence of characters.
2. Dollar Sign ($) is a Regex symbol that must match at the end of the URL/line.

17. Why is robots.txt file important?

Search Engines crawls robots.txt File first, and next to your website, Search Engines will look at your robots.txt File as instructions on where they are allowed to crawl or visit and index or save on the search engine results.

Robots.txt files are very useful and play an important role in the search engine results; If you want search engines to ignore or disallow any duplicate pages or content on your website do with the help of robots.txt File.

Helpful Resources:

1. What is the Difference Between Absolute and Relative URLs?

2. 16 Best Free SEO WordPress plugins for your Blogs & websites

3. What is Canonicalization? and Cross-Domain Content Duplication

4. What is On-Site (On-Page) and Off-Site (Off-Page) SEO?

5. What is HTTPS or HTTP Secure?

We are an Instructor's, Modern Full Stack Web Application Developers, Freelancers, Tech Bloggers, and Technical SEO Experts. We deliver a rich set of software applications for your business needs.

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published.


Advertising: What Kind of Ad Is Right for Your Business

In this article, you will learn the basic kinds of advertising and which one is right for your business. What Kind of Ad Is Right for Your Business.




Advertising What Kind of Ad Is Right for Your Business

Business is full of risks although it gives infinite opportunity to its owner. Well-chosen strategies help entrepreneurs start businesses and grow them up without big losses.

Advertising is part of the most important mechanisms that give businesses a hand with promoting new products and a brand in general. All kinds of companies, from the huge and established to the small and unknown, need to woo the target audience and propose their goods.

For new firms and start-ups, it can be a bit tricky to find their customers. However, there is nothing impossible. Advertising exists to show this world new brands and develop purchasing of existing ones. If you ask yourself questions about how it works and how you can set up ads better, you might want to read this article.

In this article, you will learn the basic kinds of advertising and which one is right for your business.

1. Main Reasons Why You Should Use Advertising in Your Business

Reasons for Small Businesses

It is obvious, small companies might lose out to huge local and international companies. Therefore, the main aspects of a tiny company life cycle are finding new clients and maintaining a stable large number of them. Advertising, especially a target one, creates a better image of the company and helps stand out from the crowd.

Reasons for Large Enterprises

If your company has good sales and your brand is well-known among a great number of people, it is not a reason to stop striving for better results. Recalling the history of international labels, huge companies can become change agents! For instance, the modern appearance of Santa Klaus and his helper Rudolf as a character were created in the early decades of twenty century.

Santa Klaus with a red suit was part of Coca-Cola’s advertising campaign. Many corporations influence society by helping children in Africa, solving problems on cocoa farms, and so on. In this case, they not only raise their reputation but also create eco-friendly trends.

Social Media Ads

2. Types of Advertising

The first and the most basic systematization comprise the ideas for whom these ads were created. In this term, we analyze the firm-orderer.

a. N-specific advertising

N-specific advertising promotes something particular. It can be category-specific, product-specific, store-specific. Category-specific and product-specific ads focus on products or firm lines of them. It does not promote the brand by and large. Although, product-specific ads are great for limited promotions when category-specific ads are usually indefinite and do not showcase the brand.

The last one is suitable for almost every competitor on the market. The most helpful advertising in this section is store-specific. Due to the highlighting of the concrete store, it makes it possible to appeal to local customers.

b. Franchise advertising

That is the most powerful advertising since every person who bought a franchise performs as a part of a big company and supports their standards. Consequently, the popularity applies to every business owner. Franchise advertising includes a tremendous campaign that makes the company famous. It is a good point for those who do not understand exactly how to build their own business but want to try.

There are many types of advertising. The chosen type depends on the target audience with social and demographic parameters. Although we can distinguish advertising in their form. In this article, we should find out what the main types exist:

c. Search Engine Advertising

Search engine ads are increasing in popularity since almost every person in the world started using laptops and smartphones that are connected to the World Wide Web. There is a lot to gain from search engine advertising. At first, it is pretty cheap in comparison with old-fashioned siblings. Secondly, a business owner has all the statistical information after the campaign.

The third point is that this sort of ad uses accurate targeting. Remember, that optimization of advertising spend and targeting is not a piece of cake. It is better to use the help of specialists or try AI Ads.

d. Social Media Ads

Social networks are very suitable for advertising a wide range of products. The most popular social media are Facebook and Instagram. Facebook can provide marvelous targeting optimization since this company has a large number of information about users.

They know the age, sex, interests, location, and so forth thus can find your audience fast and accurately. The most obvious benefit of using Facebook for ad posting is that there are many groups of interests where people discuss them.

Some companies do not even have websites because they can use Facebook or Instagram for their business. Instagram is oriented on visual content like photos and videos. It makes these social networks suitable for masters that use portfolios for promoting themselves. The one more specialist-oriented place is LinkedIn, although ads are significantly more expensive there.

Dancers, psychologists, and lecturers can find useful TikTok and YouTube where you can buy advertisements or film your informative videos. Making media content, you can face problems with file size or type. Use MP4 compressor and file converters to avoid difficulties.

Other opportunities. Other opportunities include pay-per-click Google ads and paid posts. They are not so powerful although Google has a huge database as Facebook and paid posts are ok for niche magazines.

e. Offline Ads

Offline advertising has its pros. It can cover audiences that do not use the Internet a lot (older generation) or drive every day (radio is the most suitable there). Print advertising, magazines, ads on radio and TV, cinema ads, billboards and banners, direct mail — here are examples of offline advertisements.

3. Choose the Type of Advertising Depending on Your Business Needs

When choosing the type of ads for your company, remember about the target audience and the budget. Online advertising is more modern and has pros such as the opportunity to check click-through rate and accurateness. Likewise, you can use partnerships and sponsorships to promote your company. It will help you create business relationships that support your company by extension.

Continue Reading
Marketing5 hours ago

Manufacturing Cosmetics: How does it work?

Internet2 days ago

6 Fun Activities For Your Next Virtual Corporate Event

Bitcoin3 days ago

Best Dogecoin Mining Pools to Join in 2022

Mobile Apps4 days ago

Why is Geo Location So Important for Delivery Apps?

Internet4 days ago

3 Advantages of Having a Communication API Platform

Business6 days ago

Six Ways You Can Start an Online Counseling Business

Bitcoin6 days ago

What Opportunities of Cheap Cryptocurrency Can be Used for Investment

Computer1 week ago

Dedicated Participation in the RBI Assistant Mock Test

Big Data2 weeks ago

Benefits of Data analytics for Your Business

Cryptocurrency2 weeks ago

Top 5 Advantages of Using Crypto Trading Bots