---
title: Migrate from uploaded audiences to list attributes
slug: web-experimentation/docs/QuWZ-migrate-from-uploaded-audiences-to-list-attributes
docTags: 
createdAt: 2026-07-20T15:44:46.723Z
---

- Optimizely Web Experimentation
- Optimizely Performance Edge

[List attributes](docId\:Ua8rT10ZkIkp8D03ofkxW) target visitors based on their membership in an audience you already defined somewhere outside of Optimizely Web Experimentation. With this feature, you import a custom list of users and then create audience conditions based on those lists.

The benefits of list attributes include the following:

- **Data upload methods** – In-browser, REST API, Amazon S3
- **List size limit** – Unlimited (when uploading via Amazon S3)
- **Ingest speed (time between data upload and availability of data for targeting)** – Up to one hour, and typically much faster
- **Management interface** – Optimizely Web Experimentation

## Audience builder

Go to **Audiences >** **Saved** and select an audience or create a new one. The audience builder is where you go to create Optimizely Web Experimentation [audiences](docId\:tSoFLwt3tc93lZ30vPaLd). Go to  **External Attributes >** **List Attributes** and drag the attribute you want into the Audience Builder.

![targeting-audience-attirbutes-2.png](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/8U759LrIIaRmkX-rjYY04-20260720-150202.png)

You can also search for a specific list using the **Browse by Name** search box.

## Management interface

Go to **Audiences > Attributes** to view the management interface where you create, modify, and archive lists in Optimizely Web Experimentation.

![targeting-audience-attirbutes-1.png](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/RgPYnyYg2-j3OkRf01V3Y-20260720-150202.png)