Skip to main content

Everything you need to learn Optimizely X in one place: See our resource pages for Web Experimentation and Personalization.

Optimizely Knowledge Base

Frequently asked questions in Optimizely Classic: Experiment setup

This article is about Optimizely Classic. If you're using Optimizely X, check this article out instead.
relevant products:
  • Optimizely Classic

  • Answer frequently asked questions about experiment setup in Optimizely Classic

Experiment setup 

Don’t see your question on this list? We welcome your feedback! Please scroll to the bottom of the page to click open the dialog box. Select the No option, then let us know what you're looking for.

Is there a delay between when I click SAVE EXPERIMENT and when my changes are reflected live? 

When you save an experiment, there are two delays that you may run into when attempting to preview your variations:

  • When you click "Save Experiment," there may be up to a 5 second delay before your new account JavaScript file is uploaded to Optimizely's static file origin server. You can access this file directly at this URL: where XXXXX is your Account ID (you'll find this in your Optimizely snippet when you click "Implementation" in the Optimizely Editor).
  • There may be a delay of up to 5 minutes before that file is then propagated to the edges on Optimizely's CDN (Akamai). You can access this file directly at this URL: where XXXXX is your Account ID. This file is referenced directly in your Optimizely snippet (click "Implementation" in the Optimizely Editor).

How does this affect you? Here's a timeline illustrating when you'll be able to observe new changes:

  • t = 0 : "Save Experiment" clicked
  • t = 5 seconds : Hosted Preview should now work correctly if you don't have your snippet on your site
  • t = 5 minutes : Live Preview should now work correctly if you do have your snippet on your site

How do I test two pages against each other? 

If you want to test two URLs against each other -- such as two home pages or two landing pages, you'll set up a redirect experiment.

If you'd like to test two entire sites against each other and map the URLs one to one -- such as in a redesign -- try redirect URL mapping.

How can I run an experiment on a shopping cart that exists behind a login? 

See our article on Creating an Experiment on Pages that Require a Login or Intranet Pages.

Some elements are missing when I load my site in the Editor. Why is some of my content missing in the Editor? 

If your page is not loading in the Editor, first confirm that the correct snippet is on the page.

  • If the snippet is not on your page, the Optimizely Editor will load your page through a proxy, injecting a placeholder snippet.
  • This works just fine in most cases, but can occasionally cause some display issues.

Next, confirm whether you’ve enabled mixed content.

  • Certain browsers have recently implemented a security measure, which blocks insecure content (for example, an http image) from being loaded by an https page.
  • We have an article describing mixed content and how to enable it.

Finally, make sure your site can be iFramed.

  • If you have confirmed both of the above and you are still unable to get your page into the Editor, there may be a restriction on your own website that is preventing Optimizely from loading your page.
  • Check with your developer team to see if your site’s security settings allow it to be iFramed by a third party domain. For more information, read Combating Clickjacking with xFrame Options (non-Optimizely article).

I want to make changes to an element that appears on many pages, like a navigation bar, and make sure that it stays consistent for the visitor. How can I run an experiment on an element that appears on multiple pages? 

Recommended - URL Targeting Substring Match: The most common way to ensure your experiment runs across all product pages on your site is to use a substring match in Options > URL Targeting. We walk you through how to set this up in our URL Targeting article.

Alternate solutions:

Regular Expressions or Custom Tags: If there is no unique substring that is shared across your target page URLS, you’ll need to use a Regular Expression match or add custom tags to each page you want to target.

Experiment CSS: If you're making site-wide changes, you can use Optimizely's Experiment CSS tool to add that CSS in.

Modifying Selectors: When possible, tag every item with a shared class (for items in common) and a unique ID, both across your domain and page to page. This will allow you to understand and specify what you're targeting and changing within the variation code. If you are code-savvy and know what selector you want to change, you can modify the selectors yourself in the Edit Code box.

I used the "Edit HTML" feature in the Editor to make changes, but now my interactive elements aren't working. Why did "Edit HTML" remove some functionality? 

Edit HTML should only be used to edit specific and static content on a page. For more information, read about Edit HTML in our Visual Editor article.

I made a change to an element using Interactive Mode in the Editor. Why can I see changes to an interactive element in the Editor, but not live? 

When making edits to an element on the page that is not immediately visible, such as a pop-up modal, you will often run into a timing issue where the variation code is running too soon to make the needed changes. To resolve this, you can set up manual activation mode.

How do I target experiments based on phones, tablets, or mobile devices? 

If you want to create an experiment targeting (or excluding) visitors on certain devices, you should use audience conditions.