Web Experiment targeting

Web Experiments target both pages and audiences. Amplitude evaluates page targeting first, then audience targeting. Both targeting methods evaluate locally in the browser when the page first loads.

Note

See Amplitude's pricing page to find out if this feature is available on your Amplitude plan.

Page targeting

By default, a new Web Experiment targets the URL set on creation. This is the same URL that both the visual editor and Test & Preview tool use. To target multiple pages on your site, configure additional targeting rules.

Include or exclude pages from targeting with a matching operator and a value. Amplitude recommends excluding pages only if your inclusion rules target multiple pages. For example, you could include all blog posts in an experiment, then exclude the most important posts to avoid any negative impact your variant may have.

Page matching operators

Operator	Description	Examples
URL Matches	Match the page URL, ignore query parameters or hash fragments.	`https://example.com/pricing` ✅ https://example.com/pricing#details ❌https://example.com/pricing/enterprise
URL Matches Exactly	Match the full page URL exactly.	`https://example.com/pricing?utm_source=facebook` ❌https://example.com/pricing ❌ https://example.com/pricing?utm_source=tiktok
URL Matches Pattern	Match the full page URL, including wildcards (`*`).	`https://example.com/blog/*` ✅ https://example.com/blog/my-first-post ✅ https://example.com/blog/my-second-post#get-started
URL Contains	Match the full page URL, where the URL contains a specific substring.	`/blog/my-first` ✅ https://example.com/blog/my-first-post ❌ https://example.com/blog/my-second-post
URL Starts With	Match the full page URL, where the URL starts with an exact substring.	`https://example.com/blog` ✅ https://example.com/blog/my-first-post ❌ https://example.com/pricing
URL Ends WIth	Match the full page URL, where the URL ends with an exact substring.	`/blog/my-first-post` ✅ https://example.com/blog/my-first-post ❌ https://example.com/blog/my-first-post#get-started
URL Matches Regex	Match the full page URL with a regular expression you define.	Learn Regex Test Regex

Audience targeting

Note

Audience targeting is not available on Starter plans. Upgrade to Plus to better target your users.

By default, a new Web Experiment targets all users. Audience targeting enables you to target specific users for your experiment. Users who aren't targeted see the default experience, and don't count towards analysis.

If any segments match, Amplitude buckets that user into a variant based on the configured rollout and variant distribution. For a segment to match, it must meet all conditions you set.

Parameter	Description
New Users	A new user is first seen after a specified date. When the Web Experiment SDK first sees a user, it stores the date in local storage when the SDK loads then is never updated. May not function as intended shortly after the initial script installation, when all users are new. This isn't the same as new user queries in charts and cohorts.
Returning Users	A returning user is a user first seen before a certain date. Same local considerations apply as with New Users.
Referring URL	Matches users who land on your site from a specific referrer. For more information, see document.referrer on MDN.
Landing Page URL	The landing page URL is set once in session storage when the SDK loads.
URL Query Parameters	The current query parameters on the page at the time of evaluation. Commonly used for UTM parameter targeting.
Device Category	Target users by their device type. `Desktop`, `Mobile`, or `Tablet`.
User Agent	Target based on the user agent. Useful for targeting bots. For example, exclude all users where user agent contains `Googlebot`.
Cookies	The cookies in the window at the time of evaluation.
Language	The language set in the user's browser.
Browser	The user's browser: `Safari`, `Chrome`, `Firefox`, `Edge`, `Opera`.

Bucketing

Bucketing refers to the variant a users sees, based on the rollout and distribution. Rollout is the percentage of users that should be in the experiment. Distribution defines which variant a user should see if they're in the rollout. Web Experiment distributes variants evenly by default. Amplitude recommends this distribution.

Bucketing is consistent given the user has the same ID. Since most experiments bucket by Device ID, Web Experiment may put them in a different bucket if they visit on a new device, browser, or have private browsing enabled.

Increasing rollout doesn't re-bucket users who're already in the rollout. For example, if your experiment is rolled out to 10% of users, and you increase the rollout to 50%, the original 10% of users aren't affected. If you change the distribution from evenly distributed to 20% -> control, 80% -> treatment, users who were in the control jump to the treatment.