> For the complete documentation index, see [llms.txt](https://docs.askyazi.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.askyazi.com/reach-participants/study-links.md).

# Study links

Share a study with a link or QR code, test it with the test link, and pass an ID through the link for panels and tracking.

Every study has a link. When someone opens it on their phone, WhatsApp opens a chat with your study number and a short start phrase already typed in. They tap send and the study begins. There is nothing to install and no sign-up.

{% hint style="info" %}
**In short:** use **Share link** on the **Share** tab for real participants and **Test** for yourself. The link only starts the study once the study is published. A participant who starts from a link opens the WhatsApp conversation themselves, so there is no template message to pay for to get them in.
{% endhint %}

## How it works for the participant

{% stepper %}
{% step %}

### They open the link

From an email, a website, a social post, an ad, a QR code or a message.
{% endstep %}

{% step %}

### WhatsApp opens with the start phrase

The message box already contains a phrase such as `Send to start #4F9A1`. The code at the end tells Yazi which study they want.
{% endstep %}

{% step %}

### They tap send

Yazi recognises the phrase and sends the first message of the study, usually your welcome or consent message.
{% endstep %}
{% endstepper %}

The start phrase is set once, when the study first goes live, and does not change afterwards. Links you have already shared keep working when you edit and republish the study.

## Get the link

1. Open the study and go to the **Share** tab.
2. Click **Share link**.
3. If the study runs in more than one language, pick the language. Each language has its own start phrase and link, shown with a flag, so participants see the phrase in their language.
4. Copy the link, or use the WhatsApp option to send it straight to someone.

<figure><img src="https://358667285-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FzMRQUXiGQlBwWdg6WEmG%2Fuploads%2Fq2MG7CUvFbuN1PWSwRyL%2Ffs-share-link-modal.webp?alt=media&amp;token=ed470ce4-cd8f-4330-bea3-1a748abc413b" alt="The Share study link window: the starter phrase, the live link and the test link, each with Copy, WhatsApp and open buttons"><figcaption></figcaption></figure>

## Live link and test link

|               | Live link (**Share link**)                 | Test link (**Test**)                                        |
| ------------- | ------------------------------------------ | ----------------------------------------------------------- |
| Use it for    | Real participants                          | You and your team checking the study                        |
| Responses     | Counted in results, exports and billing    | Marked as test data and hidden from results by default      |
| Repeat use    | Each WhatsApp number can take part once    | Unlimited. Run it as often as you like from the same phone. |
| AI interviews | Remembers earlier answers from that number | Starts fresh every time                                     |

The test link is reusable and unlimited. Test responses show a test chip in **Responses** and **Reporting** so you can show or hide them. See [Test your study](/study-types/test-your-study.md).

{% hint style="warning" %}
Do not test on the live link. A test run on the live link counts as a real response, and on an AI interview your number will not be asked the same questions again.
{% endhint %}

## What happens in each study status

* **Draft:** the study is not open to real participants yet. Click **Move to testing** to try it on WhatsApp.
* **Testing:** sending the start phrase gets a short testing notice and the study then runs as a test session. Answers are tagged as test data.
* **Live:** the study starts normally.
* **Closed:** the participant gets a notice that the study has closed.

See [Publish and go live](/study-types/publish-and-go-live.md).

## QR codes

To put the study on a poster, a receipt, packaging or a slide, turn the link into a QR code with any QR code generator and test it with your phone before printing. Scanning the code does exactly what clicking the link does.

## Pass an ID through the link

You can add **one** value to the link, typically a transaction ID or a panel's respondent ID. It travels with the participant and appears with their responses in Table Data and exports, so you can join Yazi data back to your own records.

* Only one value can be passed. To bring in several fields (age, region, customer segment), upload a list instead: see [People and contacts](/reach-participants/people-and-contacts.md) and [Data enrichment](/integrations-and-api/data-enrichment.md).
* Ask Yazi support for the exact parameter name to use.
* Some panel and tracking systems change or strip parts of a link. Test the full link, with your value added, end to end before launch.

Tracking which channel works best (email versus social versus QR) needs a different link per channel. The simplest approach is to pass the channel name as the one value, or to compare **Source** on the Participants tab for link versus broadcast.

## Send people somewhere when they finish

When a participant completes, you can send them on, for example to a panel's completion page, a sign-up form or a review site. Set this in **Build > Study configuration > Completion & follow-up**. **Add a button** with **Link button** puts a web link under the completion message. To send finishers into a second study instead, open **Advanced options** and choose **Redirect to another survey**.

For Prolific and PureSpectrum, use [Panel recruitment](/reach-participants/panel-recruitment.md) inside the study instead. It handles completion, screen-out and quota-full returns to the provider for you.

## Using the link in ads

The link works as the destination of a Facebook or Instagram ad. People tap the ad, WhatsApp opens and they are in. Meta also has a Click to WhatsApp ad format that opens a chat directly. If the participant arrives from a Click to WhatsApp ad, Meta gives a longer free messaging window. See [WhatsApp costs and the 24-hour window](/reach-participants/whatsapp-costs-and-the-24-hour-window.md).

## Tips for better uptake

* Say three things before the click: what the study is about, how long it takes and whether there is a reward.
* Say it happens on WhatsApp, so nobody is surprised when the app opens.
* Send people straight to the link. Every extra page before WhatsApp loses people.
* If participants know your brand, use a profile picture they recognise on your WhatsApp number.

## Limits and things to know

* One link per study (with one variant per language). Each activity in a multi-activity study can be started by its own phrase, but individual activity links only work once the study is **Live**, so testers start at the first activity.
* One value can be passed through the URL.
* Participants need WhatsApp on their phone. WhatsApp desktop works for chat questions but not for WhatsApp Flow screens.
* If the participant edits or deletes the start phrase before sending, Yazi cannot tell which study they want. Ask them to open the link again.

## Related

* [Ways to invite participants](/reach-participants/ways-to-invite-participants.md)
* [Send a broadcast](/reach-participants/send-a-broadcast.md)
* [Test your study](/study-types/test-your-study.md)
* [Panel recruitment](/reach-participants/panel-recruitment.md)