# Click to Start

> Run a workflow by pressing its trigger on the canvas, using the testing data you saved on it.

**Click to start** runs the workflow when you press it on the canvas. There is no schedule, no incoming request and nothing to connect: the run begins because you asked for it.

Reach for it while you are building something, or for a job somebody runs now and then rather than on a timetable: a monthly export, a one-off tidy-up, a report somebody asks for.

## What the run receives

The workflow starts with the **testing data** saved on this step. That is the whole input, so whatever the rest of the workflow reads from step 1 comes from there.

Set it once and every press uses it, which is what makes this trigger useful for building. The input is the same each time, so a change in the result came from your edit rather than from the data.

## Setting it up

### Add the trigger

Open **Tools** in the dock and choose **Click to start**.

### Give it testing data

Open the step and fill in **Testing data** with the shape the workflow expects, for example:

```json
{ "email": "someone@example.com", "plan": "pro" }
```

### Build the rest of the workflow

Reference those fields by the trigger's step number, so `{{ 1.email }}` and `{{ 1.plan }}`.

### Press it

Click the trigger on the canvas. The run starts and the Execution log fills in as it goes.

## When to use something else

- **On a timetable:** use the [Scheduler](/build/triggers/scheduler).
- **When another system has something to tell you:** use a [Webhook](/build/triggers/webhook).
- **When somebody outside the workspace needs to start it:** use the [Chat Trigger](/build/triggers/chat), or have another workflow call this one with a [Subflow](/build/action-steps/trigger-workflow) step.

The difference that matters: Click to start needs somebody with access to the canvas. The others do not.

## What's Next?

- Put it on a timetable with the [Scheduler Trigger](/build/triggers/scheduler).
- Read what a run records in [Executions](/build/core-concepts/executions).