If you are looking for an online survey panel similar to Prolific, you might consider the following options:

1. MTurk (Amazon Mechanical Turk): MTurk is a well-known platform for recruiting participants for surveys and other tasks. It offers a large pool of participants from diverse backgrounds and has a reputation for providing fast and cost-effective access to research participants. However, MTurk participants tend to be more focused on earning money than on contributing to research, which can impact the quality of data obtained.

2. Qualtrics Panel: Qualtrics offers access to diverse research participants through its Research Services division. This panel includes individuals from a range of demographic backgrounds and geographic locations and can be targeted based on specific criteria such as age, gender, and income level. Qualtrics also offers tools for survey design and data analysis.

3. UserTesting: UserTesting is a platform that offers access to a panel of individuals who are willing to provide feedback on websites, apps, and other digital products. It allows researchers to gather feedback on user experience and user interface design and can be used to test prototypes, wireframes, and other design concepts.

4. Respondent: Respondent is a platform that connects researchers with a pool of individuals who are interested in participating in market research studies. The platform allows researchers to target participants based on specific criteria such as age, income, and geographic location and provides tools for survey design and data analysis.

These are just a few options to consider when looking for an online survey panel similar to Prolific. It's important to evaluate the features and pricing of each platform and the quality of the participants they provide to determine which is the best fit for your research needs.