# Hidden Fields > Add hidden fields to a MetaSurvey survey to track who is responding and where responses come from. Source: https://getmetasurvey.com/help/survey-tracker/ Hidden fields are extra GET parameters in your survey URL. You can add hidden fields to your survey to collect it with other responses. This helps you track who is completing your survey or where respondents are coming from. ## How it works? To get started, copy your survey link: ``` https://public.getmetasurvey.com/survey/62640bed1a3ba400127faff9 ``` Then, add your desired GET parameters, like this: `?key1=value1&key2=value2` The final URL will look like this: ``` https://public.getmetasurvey.com/survey/62640bed1a3ba400127faff9?key1=value1&key2=value2 ``` **Examples:** - **Tracking Campaigns:** Add UTMs to your survey URL to monitor the effectiveness of different campaign channels: ``` https://public.getmetasurvey.com/survey/62640bed1a3ba400127faff9?utm_medium=email ``` - **Identifying Respondents:** Want to detect users who completed your survey? Include a unique identifier like user ID (UID) in the URL: ``` https://public.getmetasurvey.com/survey/62640bed1a3ba400127faff9?uid=79350 ``` ## Hidden Fields in Analytics: If hidden fields exist, they will be included in the **URL params** column: ![URL params column](https://getmetasurvey.com/help/survey-tracker/cgvL2Fhq0y1Cfnp4SMZXYWpN2lI.webp)(width: 1520, height: 819) ## Adding Hidden Fields to Embedded Surveys: Hidden fields allow you to pass additional parameters (such as user IDs) into the survey. These parameters can be used for tracking or personalization. **Frame Embed** To add parameters to a **Frame Embed**, modify the `
` element by adding `data-ms-params` with a JSON string of your parameters: ```
``` **Full-Page Embed** The same approach applies to a **Full-Page Embed**: ``` Survey
``` **Popup Embed - Side Button** For the **Side Button Popup**, add parameters using `w.msParams`: ``` ``` **Popup Embed - CTA Button & Inline Button** For **CTA Buttons** and **Inline Buttons**, use the same `data-ms-params` approach as the Frame and Full-Page embeds: ```
```