Filed under Chrome Extension, Page Load Time, Website Speed Testing.

LoadFocus today announced the release of its Google Chrome extension as the newest addition to their testing platform. LoadFocus’s Chrome extension allows users to run free website speed tests and see what’s slowing down their websites. They can monitor changes over time for each page and get advice on how to reduce page load times, see also our article on how to boost speed and improve overall SEO of your website.

It’s an easy to use tool which can optimise the performance of your website.

No need to install anything to run a page load test, the Website Speed Test Chrome extension will create everything for you automatically.

Get the Website Speed Testing Chrome extension today.



Filed under Page Load Time, Website Speed Testing.

Slow websites, or slow pages are not good for SEO. In these days everything needs to be fast. If your website loads in more than 2 seconds you’ll probably lose customers, either by not getting ranked properly in search results, either by customers leaving your website due to its speed.

Use a free website speed testing tool like

Here are 5 website speed improvements tips that we consider important:

  1. Reduce the overall size of your assets:
    • Minify your JavaScript, CSS files
    • Resize images by using free resizing online tools without losing image quality
    •  Compress assets using Gzip to reduce load time by as much as 70%
  2. Reduce the size of your HTML code
    • Uglify your HTML code of your web pages
    • Release features with fewer lines of code (inspect 3rd party plugins like Editors to understand how much markup they add to your website)
  3. Upgrade your dependencies to the latest version
    • usually the latest versions has many performance improvements
    • even if you need to do some code changes in order to make your code work with the latest version, we still believe it worth giving a try
  4. Reduce the Number Of HTTP Requests
    1.  Group JS and CSS files together
    2. Batch HTTP requests
  5. Use browser caching and remove unused 3rd party libraries or plugins is a Cloud Website Speed Testing Platform used for Testing Websites from Multiple World Locations and Inspecting Result with Full Analytics.

Filed under Load Testing, Page Load Time, Performance Testing, UI Testing.

During Speed testing of your website or web application using LoadFocus ( on the Advice section you might get the tip that you need to enable compression like in the image below:




Compressing responses often significantly reduces the size of transmitted data.
Because the compression happens at runtime this can add a big processing overhead which can affect the performance in a negative way.

Nginx if configured correctly compresses the responses before sending them to the clients and does not double compress the responses which have been already compressed.

In the next tutorial we will show how you can enable compression in case you are using Nginx to serve your files.

1. First locate the Nginx configuration file – nginx.conf
2. Once you located the file open the file and make sure that inside the configuration you can find the following flags:

<strong>gzip on</strong>;
<strong>gzip_disable</strong> "msie6";

<strong>gzip_vary</strong> on;
<strong>gzip_proxied</strong> any;
<strong>gzip_comp_level</strong> 5;
<strong>gzip_buffers</strong> 16 8k;
<strong>gzip_http_version</strong> 1.1;
<strong>gzip_min_length</strong> 1000;
<strong>gzip_types</strong> text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;

3. Explanation of the flags:

gzip on – enables compression

gzip_disable “msie6” – disable compression for IE6 as IE6 doesn’t always read and cache gzipped content properly and you end up with mangled code

gzip_vary on – enables / disables inserting the “Vary: Accept-Encoding” response header field if the directives gzip, gzip_static, or gunzip are active

gzip_proxied any – enables or disables gzipping of responses for proxied requests depending on the request and response; the fact that the request is proxied is determined by the presence of the “Via” request header field

gzip_comp_level 5 – sets a gzip compression level of a response; the values that are acceptable are between 1 and 9; 5 is a good compromise between size and cpu usage

gzip_buffers 16 8k – sets the number and size of buffers used to compress a response; by default, the buffer size is equal to either 4K or 8K, depending on a platform

gzip_http_version 1.1 – sets the minimum HTTP version of a request required to compress a response

gzip_min_length 1000 – specifies the minimum length of the response to compress; the default is 20 bytes; don’t compress anything that’s already small and unlikely to shrink

gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript
– by default gzip compression is applied only to responses with MIME type text/html; to enable it for other types of MIME we need to add them to this flag

4. The flags that are most important are the “gzip on” and “gzip_types”

5. The directives/flags that configure compression can be included in the http context or in a server or location configuration block

6. Restart Nginx by doing sudo service nginx restart

7. After you’ve finishes to enable compression on your server run the LoadFocus speed test again. This time the tip regarding to Enable compression should say that everything is fine. is a Cloud Testing Platform used for Load and Performance Testing for Websites and APIs and Website Speed Testing with Analytics.

Filed under Apache JMeter, Test Automation.

In order to add an XPath Extractor to your JMeter script you need to begin by installing JMeter and create an HTTP Request. If you want to check how you can create a load test with Apache JMeter, please check our previous blog post.

Start by adding a XPath Extractor to your HTTP Request by following the below steps:

  • Select the HTTP Request on the left side, and Right-click it
  • Hover to Add -> Post Processors -> XPath Extractor
  • Click on XPath Extractor

Update the XPath Extractor with the desired variable names and expected XPath. We are going to make an HTTP Request to and based on the HTML response, we are going to extract the H1 tag from the website and use it in the next request.

Update the XPATH Extractor with the following details:

  • Reference Name: The name of the JMeter variable in which to store the result, var1
  • XPath Query: Element query in XPath language. Can return more than one match, //html//h1
  • Default Value: Default value returned when no match found. It is also returned if the node has no value and the fragment option is not selected, NOTFOUND


Copy the existing HTTP Request and add the variable in the Server Name:


In the View Results Tree, you can see that the variable var1 contains the content extracted from the XPATH //html//h1,  Example Domain, and the second request is going to be:

  • GET Domain/
jmeter-xpath-extracted-variable result-from-xpath-extractor

Have in mind that you can check the XPath also from inside the browser’s console, by typing the following:


which should output the element’s content that was saved inside the ${var1} variable from XPath Extractor.


In order to run load tests with thousands of threads (users) and to run load tests from different world locations, you can use which offers a cloud load testing service, easy to use, which keeps all your tests and test runs in the history automatically.

Filed under Load Testing, Website Speed Testing.

Get every month 5 free load tests and 5 free website speed tests to your Free plan by adding our code in your website.

Our Link Program lets you run 5 website load tests and 5 free website speed tests per month completely free!

Just add the LoadFocus link to your website to upgrade. Here is the link:

<a href="" title="load testing tool" ></a>

Once the link is visible on your site, we’ll automatically give you 5 load tests and 5 website speed tests per month for free. is a Cloud Testing Platform used for Load and Performance Testing for Websites and APIs and Website Speed Testing with Analytics.

Filed under Load Testing, Performance Testing, Test Automation, Uncategorized.

What are assertions ?

In case you are not familiar with the term, an assertion “is a test / a condition that must be tested to confirm conformance to a requirement”. Basically a test assertion is – a condition that compares the expected value with the actual value for a specified use case.


Why should I use assertions ?

Before we deliver a product, we need to run many test assertions to make sure the product meets the customer’s expectations. Also, you can check our intro blog post regarding how to run a load test with Apache JMeter.



Should we use assertions in the JMeter tests ?

Usually assertions are not used when we create the scripts for load or stress testing an application. Most of the tester that run
these kind of tests base their results only on the response status codes that the application under test returns. This might be a problem and might make the final results not accurate.

What are the cases in which not using an assertions may affect your final results ?

Not all the time a successfull response from the server (200 OK) means that the application responded as expected.
You may ask yourself and the a few cases are mentioned below:

  1. the application redirects to a maintaince page
  2. the application responds a 200 OK but sends an error message in the body of the response indicating a error message
  3. the application redirects to an error page and sends back a 200 OK with and error message indicating why the error returns

To avoid these kind of errors to affect your performance report is a very good idea to use assertions:

  • in GET/POST/PUT/PATCH methods
  • in API performance testing
  • in functional testing

Be aware that if your are creating a long running test or a test with a lot of requests is good not to use a lot of assertions as
they tend to consume quite a bit of memory which could make your JMeter tool crash and means starting the test again.

What type of assertions does JMeter support ?

There are several types of assertions that you can use in your test scripts.
The most used ones are:

  • Response Assertion“: the response assertion control panel lets you add pattern strings to be compared against various fields of the response
  • XPath Assertion“: the XPath Assertion tests a document for well formedness, has the option of validating against a DTD, or putting the document through JTidy and testing for an XPath (if that XPath exists, the Assertion is true)
  • HMTL Assertion“: the HTML Assertion allows the user to check the HTML syntax of the response data using JTidy.
  • XML Assertion“: tests that the response data consists of a formally correct XML document; it does not validate the XML based on a DTD or schema or do any further validation.
  • Compare Assertion“: can be used to compare sample results within its scope; either the contents or the elapsed time can be compared, and the contents can be filtered before comparison.
    Compare Assertion MUST NOT BE USED during load test as it consumes a lot of resources (memory and CPU). Use it only for either functional testing or during Test Plan debugging and Validation.
  • Size Assertion“: verifies that each response contains the right number of bytes in it; you can specify that the size be equal to,
    greater than, less than, or not equal to a given number of bytes


How much do assertions consume in terms of CPU and memory ?

If the test that your are using is a long running test or makes a very large number of requests you may encounter unexpected failures related to “out of memory” errors or similar.

In terms of resources the HMTL Assertion, XML Assertion or Compare Assertion consume a lot of resources so is a good idea to avoid using those in long running tests. The other assertions does not have a very bad impact on the resources so they can be used without a problem.


Which is the scope to which the assertions apply ?

There are 3 cases related to which scope an assertion applies to:

1. applies to all the child requests

Screen Shot 2016-04-11 at 11.05.53


2. applies to all the sibling requests

Screen Shot 2016-04-11 at 11.05.47


3. applies only to one specific request

Screen Shot 2016-04-11 at 11.05.38


How to use a “Response Assertion” in JMeter ?

Response Assertion is one of the most widely used assertion as it allows to verify the content of the response, status code or headers.

It can be configured to verify:

  • the different segments of the response like text (response body)
  • the document type like pdf, doc etc
  • the headers
  • the response code (2xx, 4xx)
  • response message (description of code) and response headers
  • tests the response against a pattern string which can be a plain text or a Perl5 regular expression; the specified pattern is matched against the selected segment of the response


Let’s start by adding a response assertion that expects that the response code is 200.

Screen Shot 2016-04-11 at 11.24.32


We will now add another assertion that expects that the text “wikipedia” is present in the response of the server.


Screen Shot 2016-04-11 at 11.26.17


Running the script will show that that the request succeeded without any problem.

Screen Shot 2016-04-11 at 11.26.34


Now we will change the text of the second assertion to “dummy_text_inexistent” and run the test again.

Screen Shot 2016-04-11 at 11.29.34

In the next tutorials we will show you how to use the rest of the assertions that are supported in JMeter.

You can also use LoadFocus to load test your websites, APIs or any web-app with thousands of users from AWS cloud locations.


Filed under Page Load Time, Website Speed Testing.

During Speed testing of your website or web application using LoadFocus ( on the Advice section you might get the tip that you need to enable compression like in the image below:


The question is why and how do you do that ?


  • The response to the why is that enabling gzip compression can reduce the size of the transferred response by up to 80-90%;
    This has the following benefits:
  • significantly reduces the amount of time it takes to download the resources
  • reduces data usage for the client
  • improves the time to first render of your pages
  • a better user experience for your customers
  • a better monetization for your web application

You can enable gzip compression for CSS and JavaScript files.
Apart from these any text data or XML files will also benefit from gzip compression. Don’t use gzip for image or other binary files.

Image file formats supported by the web, as well as videos, PDFs and other binary formats, are already compressed; using gzip compression on them won’t provide any additional benefit.

By default all modern browsers automatically negotiate gzip compression for all HTTP requests that are done.
To help you enable gzip compression on your server you can check out the following project

that contains the sample configuration files for quite a few different servers.
After you’ve finishes to enable compression on your server run the LoadFocus speed test again. This time the tip regarding to Enable compression should say that everything is fine. is a Cloud Testing Platform used for Load and Performance Testing for Websites and APIs and Website Speed Testing with Analytics.