Access a full range of advanced settings that can be used within our standalone analyses as our comparison tools and our monitoring features.
Use the advanced settings to duplicate any kind of browsing context.
Advanced settings overview
Bandwidth
The Bandwith tab can be used to better understand the Blocking Time.
For example: Set up a monitor with no latency and a really high bandwidth, so you will eliminate all network-related issues, which will put the focus on CPU limitations. This can be useful to determine priorities.
Select an option from the drop down menu or select custom to set your own value for downstream and upstream bandwidth.
Tip: Latency is injected into the network exchanges between our browser and the contacted web servers. It is added to the "natural" latency that is very limited within our infrastructure, as our test probes are based in datacenters.
Basic authentication/.htaccess
Use .htaccess to analyze a page behind a login (Basic authentication). This setting is typically used for setting up monitors on pre-production or test environments.
Enter a valid login and password into the relevant boxes.
Tip: We recommend that you use the Scenarios feature to track specific pages on Single Page Application (SPA funnels) in a post log-in area.
Local Storage
Use the Local storage tab (which also provides Session storage capabilities) to initiate the local storage state in the web browser to emulate a specific user’s context.
For example: You can use the Local storage tab to emulate user consent from some Consent Management Platforms (CMP) that leverage this kind of storage.
For example, if you set a Local storage entry on http://example.com, the entry is accessible from both http://example.com and https://example.com.
Limitations related to Session storage
Due to technical constraints, Session storage entries are added at the beginning of the page loading. Therefore, Speed Analysis Lab cannot guarantee that getting the items from the Session storage at the beginning of the page life cycle (before DOM Interactive) will be successful.
If you encounter this limitation, you can use the Scenario feature to bypass it with an initialization step.
Cookies
Cookies allow website owners to store a piece of information on their visitors browser. Setting up cookies for your web performance tests may be useful:
- to determine a user's profile (e.g.: favorite store)
- to enforce the version to test while using an A/B testing service
- to simulate a session via a test login
Once stored on the browser, the cookie is sent within the next HTTP requests to the server. Nevertheless, it's not necessary sent within all requests. You can specify a specific domain and path on which it's applied.
Tip: For a cookie to be sent on a domain as well as on its sub-domains, it's required to add a point . as a prefix. For example, having a cookie with .domain.com
as a Domain value will allow to send the cookie for requests on www.domain.com, domain.com or again on cdn.domain.com
HTTP headers
Configure custom HTTP headers (override the default HTTP headers).
Use cases for this setting include:
- Change the user agent and test your web pages with the Google bots user agent
- Add some cookies
- Activate the debug mode of your CDN
- Enforce the web page version to test while using an A/B testing service
Blocklist
Use blocklist to block a URL or stream from the report you are running.
Use cases for this setting include:
- Ignore a resource that may tamper the overall loading time of your web page
- Compare one single page's performances with or without social widgets (facebook, etc.) or any other specific resource
- Measure your web page performances while excluding all of the external resources to focus on those hosted on your own domain
DNS Mapping
Use DNS mapping to enforce the DNS resolution to a different IP address than the DNS server response.
Use cases for this setting:
- Bypass a cdn to target the root server. It can be helpful to pinpoint cdn related issued and evaluate the network cost of the cdn (by comparing with classic report).
- Connect to a pre-production or test server which can only be targeted through host manipulations.
While running its web performance tests Speed Analysis Lab requests, by default, the Google DNS server in order to get back the related IP address of the website's domain (DNS resolution). Our DNS mapping option allows you to enforce the DNS resolution to a different IP address than the DNS server response.
In order to simulate a failure of a third-party service provider, we recommend you to map the provider's domain on blackhole.webpagetest.org
Disable Animations
Your web pages may contain animated media, like automated carousels. Those elements are likely to tamper with some Speed Analysis Lab measures: Speed Index and Visually Complete. In fact, these 2 indicators are computed from a video analysis of the web page loading. As a consequence, they rely on the display constancy and are very sensitive to animations.
To improve your test results, Speed Analysis Lab offers 2 options to deactivate 2 types of animations.
SetTimeout() and SetInterval() are 2 JavaScript functions that are often used to program the triggering of an execution, within carousels as an example.
Be careful though: deactivating those functions may impact some other behaviours on your website. You should look at the changes (with/without this option) within the filmstrip and the number of requests of your tested web page.
The second option allows you to deactivate all of the animations related to CSS3 usage.
Adblock Activation
Test your web page performance with this activated extension.
AdBlock does not block all the ads so you can additionally use the Blocklist feature.
Tip: For each Chrome update on our infrastructure, AdBlock is also updated, as its list of blocked ads.
HTTP/2 Support
That option allows you to disable HTTP/2 support on the web browser that runs your test. As a consequence, all the HTTP transactions that should have used this protocol will use HTTP/1.1 instead.
Thanks to this feature, you will be able to compare your website performance through a web browser supporting HTTP/2 against another browser that doesn't.
Disabling HTTP/2 support for a web page that doesn't load any HTTP/2 requests won't have any impact (our option does not let you simulate your website performance if it was using HTTP/2).