We’ve compiled a list of questions that customers ask us the most. Click a question to jump to it in this article! 

Account questions

General questions

Experiment setup

Goals and results



Looking for the definitive guide to getting up and running with Optimizely? Learn and practice your Optimizely skills and web optimization strategy, from beginner to advanced, in Optimizely Academy. Or check out these short videos that explain how to set up an experiment, how to QA your experiment, and how to interpret your results.

Have questions about Optimizely for iOS? We have a separate mobile FAQ for that!

Have a question about Optimizely or website optimization? Head over to the Optimizely Community to post a discussion and see what others are talking about.

Looking to troubleshoot your experiment? Check out this list of common issues.

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.

Account questions

What are Optimizely's password requirements?

Passwords have to be at least 8 characters long and use at least two of the following: lowercase letters, uppercase letters, numbers, and symbols.

I'm having trouble accessing my account. What should I do?

Here are a couple of fixes you may want to try:

  • Log in after clearing your browser cache and cookies, or open a fresh Chrome Incognito browser window and then log in
  • Disable any browser extensions that you currently have running
  • Log in using a different browser


You must close all Chrome Incognito windows to fully clear the cache and cookies. Do this before trying to log in with a fresh Incognito window.

I didn't receive an email to reset my password

If you do not receive an email after 1-2 minutes, check your spam folder. If the email is not in the spam folder and you are using a business email, check with your IT team to see whether emails from Optimizely are being auto-detected as spam. You may need to change some settings for the emails to make it through.

Use the Need help logging in? link on the Home Page to reset your password.

I need help from the support team

Still can't log in? On the Home Page, click the link Can't log in? Click here. This sends an account recovery request to our support team, who will contact you within 24 hours.

Is it possible to run experiments on multiple domains with one account?

You can run experiments on as many domains as you like with a single account. In fact, you can actually use the Options > URL Targeting controls to run a single experiment on multiple domains at the same time. However, you'll want to be aware of Optimizely's cross-domain tracking limitations.

Some Optimizely plans can create multiple projects to manage different domains. For more information about projects, click here.

What happens if I exceed my monthly unique visitors?

If you exceed your monthly unique visitor (MUV) limit on an Enterprise plan, you will be billed an overage fee. If you feel that you've received this overage in error, please contact our support team and we'll be happy to assist you.

If you exceed the 50,000 monthly unique visitor limit on the Starter plan, your experiments will be paused until the beginning of the next monthly billing cycle. This cycle begins on the day of the month when you started your subscription.

When your experiments are paused, your visitors will see your original site, and not the variations you created in Optimizely. If you think you need more than 50,000 monthly unique visitors, please call us about a customizable Enterprise plan at 1-800-252-9480.

General questions

How will Optimizely affect my pageload times? Will my site lag?

The short answer: no. Your site shouldn't lag, and any delay to pageload times should be undetectable to the human eye.

We understand that even small increases in page load times must be taken seriously, so we do everything we can to make sure that Optimizely's impact on your page is as small as possible.

There are two Optimizely endpoints that receive web requests from your pages while an Optimizely experiment is running:

  1. Your Optimizely JavaScript (referred to in your snippet) file is downloaded from either of our CDN providers, Akamai or Edgecast, based on optimal proximity and reliability
  2. Your visitors' browser sends tracking requests to Optimizely

Your Optimizely JavaScript file is referred to in your Optimizely snippet and is downloaded by your visitors' browsers at the very beginning of the page load process. It weighs in at ~35kb, is entirely static, and will be cached in your visitors' browsers after the first request. It's also hosted on Akamai and Edgecast, our global CDN providers, so there is no load-time dependency on Optimizely's servers.

The Optimizely JavaScript file download occurs in parallel alongside other JavaScript and CSS files on your site and should take roughly 80-100ms to complete in North America.

Your visitors' tracking requests are made when your visitors land on a page containing your Optimizely snippet. This is how Optimizely collects analytics on your conversion goal performance. These requests are asynchronous, non-blocking, and only occur for visitors that have been placed in at least one experiment. They should have no effect on your page load time.

How does Optimizely affect my search ranking or SEO (Search Engine Optimization)?

Google permits and encourages A/B testing and has stated that performing an A/B or multivariate test poses no inherent risk to your site’s search rank. However, it is possible to jeopardize your search rank by abusing an A/B testing tool for purposes such as cloaking. We have more in-depth information in our SEO and search ranking article.

What version of jQuery does Optimizely use?

Optimizely uses jQuery version 1.6.4 by default, but also provides the option to use version 1.11.3.

If you elect to use your own version of jQuery instead of the version bundled in your Optimizely JavaScript file, version 1.4.2 or later is required for compatibility.

How do I find more information about the Optimizely API? Where do I generate a token?

Optimizely has a JavaScript API and a REST API available.

The Optimizely JavaScript (client) API provides a way for developers to modify the normal behavior of the Optimizely snippet for specific use cases. Use the API to target activation based on specific page content or events, query the state of activation, bucketing, or conversion for use in custom analytics packages, and force visitors into specific variations, among other capabilities.

The Optimizely REST API lets you create and manage Optimizely projects and the experiments inside of them. The API is RESTful and encodes data in JSON. The sections below explain how to authenticate with the API, form requests, and consume responses.

If you'd like to generate an API token, visit app.optimizely.com/tokens and view our documentation here.

Experiment setup

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: http://optimizely.s3.amazonaws.com/js/XXXXX.js 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: http://cdn.optimizely.com/js/XXXXX.js 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 can I test two entirely different URLs against each other?

This is very simple to do in Optimizely! Just run a redirect experiment. A redirect experiment lets you redirect visitors to a different page, instead of showing them a variation that you create in the Editor. Just note that you won't see the redirected page in the Editor, and you will need to have your Snippet installed on both the original and the redirect page. If you're trying to track click goals on your redirect page, see this question about that topic.

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.

Goals and results

How does Optimizely count conversions?

Optimizely counts conversions based on unique visitors to your page, meaning that regardless of how many times a user triggers a conversion, Optimizely will count it as one visitor and one conversion.

If the visitor doesn’t trigger the conversion goal the first time he or she visits the site, but does so during a subsequent visit while the experiment is still running, the experiment still counts the conversion.

Want to learn more? Watch this short video on how Optimizely counts conversions. (More videos here.)

How does Optimizely count unique visitors?

When visitors are bucketed into an experiment, they receive an optimizelyEndUserID cookie. This cookie is used to determine whether a unique visitor has been included in an experiment. This may differ from how your analytics platform tracks unique visitors, as we explain below.

Check out this short video to learn more about how Optimizely tracks unique visitors. (More videos here.)

My Optimizely results numbers don't match the numbers in my analytics platform, like Google Analytics. Why do I see different results in Optimizely and my Analytics Platform?

Optimizely and your analytics platform may count visitors differently, but integrating them will help.

If you have not done so already, you should integrate Optimizely and Google Analytics. The integration will allow Optimizely to inform Google Analytics of the experiment and variation that a given visitor was assigned to.

Within your Google Analytics account, you’ll now be able to drill down into the data for visitors who saw one variation vs. another. This will give you a much greater insight into whether the numbers are trending in the same direction.

A primary reason for a discrepancy between your GA numbers and Optimizely’s results boils down to the way a “visitor” is counted.

  • For instance, Google Analytics uses a tracking call that is session based, meaning a single visitor can trigger multiple visits over a given period of time.
  • Optimizely, on the other hand, uses a 10 year cookie and counts unique users.
  • For additional information on Google’s sessions, check out their support article on the issue.

Read our Analytics Integration Overview for more information.

I want to track the impact my experiments have on revenue. How can I track purchases as a goal?

If your site has a purchase confirmation page, then the easiest way to track purchase conversions is to set up a pageview goal on the confirmation page.

If you also want to compare revenue for each variation, you can create a Revenue goal for your experiment. Please keep in mind that the Optimizely snippet is needed on any page on where you wish to track a goal.

I'm running a redirect experiment and I see 0 conversions for the variation on the Results page. Why can't I see any conversion results for my redirect experiment?

The most common cause for this issue is incorrect goal targeting conditions. We walk through the solution in the linked article.

Do bots get counted in results?

The vast majority of bots that can be identified by the user agent (Google, Bing, Yahoo) will be excluded from the test results. To make sure we don't violate any best practices, the different versions of your page can still be seen by the various crawlers. However, no tracking calls will be made. To make sure that your SEO is not affected take a look at this question for best practices when using Optimizely as an AB testing tool.

I don't want my own employees affecting experiment results. How can I exclude internal employees from my experiments?

You can accomplish this with IP Filtering. See this linked article for more information.