playwright/docs/src/trace-viewer-intro-csharp-java-python.md

---
id: trace-viewer-intro
title: "Trace viewer"
---

## Introduction

Playwright Trace Viewer is a GUI tool that lets you explore recorded Playwright traces of your tests meaning you can go back and forward though each action of your test and visually see what was happening during each action.

**You will learn**

- How to record a trace
- How to open the trace viewer

## Recording a trace
* langs: python

Traces can be recorded by running your tests with the `--tracing` flag.

```bash
pytest --tracing on
```
Options for tracing are:
- `on`: Record trace for each test
- `off`: Do not record trace. (default)
- `retain-on-failure`: Record trace for each test, but remove all traces from successful test runs.

This will record the trace and place it into the file named `trace.zip` in your `test-results` directory.

<details>
<summary>If you are not using Pytest, click here to learn how to record traces.</summary>

```python async
browser = await chromium.launch()
context = await browser.new_context()

# Start tracing before creating / navigating a page.
await context.tracing.start(screenshots=True, snapshots=True, sources=True)

page = await context.new_page()
await page.goto("https://playwright.dev")

# Stop tracing and export it into a zip archive.
await context.tracing.stop(path = "trace.zip")
```

```python sync
browser = chromium.launch()
context = browser.new_context()

# Start tracing before creating / navigating a page.
context.tracing.start(screenshots=True, snapshots=True, sources=True)

page = context.new_page()
page.goto("https://playwright.dev")

# Stop tracing and export it into a zip archive.
context.tracing.stop(path = "trace.zip")
```

</details>

## Recording a trace
* langs: java
  
Traces can be recorded using the [`property: BrowserContext.tracing`] API as follows:

```java
Browser browser = browserType.launch();
BrowserContext context = browser.newContext();

// Start tracing before creating / navigating a page.
context.tracing().start(new Tracing.StartOptions()
  .setScreenshots(true)
  .setSnapshots(true)
  .setSources(true));

Page page = context.newPage();
page.navigate("https://playwright.dev");

// Stop tracing and export it into a zip archive.
context.tracing().stop(new Tracing.StopOptions()
  .setPath(Paths.get("trace.zip")));
```


This will record the trace and place it into the file named `trace.zip`.

## Recording a trace
* langs: csharp

Traces can be recorded using the [`property: BrowserContext.tracing`] API as follows:

<Tabs
  groupId="test-runners"
  defaultValue="nunit"
  values={[
    {label: 'NUnit', value: 'nunit'},
    {label: 'MSTest', value: 'mstest'}
  ]
}>
<TabItem value="nunit">

```csharp
namespace PlaywrightTests;

[Parallelizable(ParallelScope.Self)]
[TestFixture]
public class Tests : PageTest
{
    [SetUp]
    public async Task Setup()
    {
        await Context.Tracing.StartAsync(new()
        {
            Title = TestContext.CurrentContext.Test.ClassName + "." + TestContext.CurrentContext.Test.Name,
            Screenshots = true,
            Snapshots = true,
            Sources = true
        });
    }

    [TearDown]
    public async Task TearDown()
    {
        await Context.Tracing.StopAsync(new()
        {
            Path = Path.Combine(
                TestContext.CurrentContext.WorkDirectory,
                "playwright-traces",
                $"{TestContext.CurrentContext.Test.ClassName}.{TestContext.CurrentContext.Test.Name}.zip"
            )
        });
    }

    [Test]
    public async Task TestYourOnlineShop()
    {
        // ..
    }
}
```

</TabItem>
<TabItem value="mstest">

```csharp
using System.Text.RegularExpressions;
using Microsoft.Playwright;
using Microsoft.Playwright.MSTest;

namespace PlaywrightTests;

[TestClass]
public class ExampleTest : PageTest
{
    [TestInitialize]
    public async Task TestInitialize()
    {
         await Context.Tracing.StartAsync(new()
        {
            Title = TestContext.CurrentContext.Test.ClassName + "." + TestContext.
            Screenshots = true,
            Snapshots = true,
            Sources = true
        });
    }

    [TestCleanup]
    public async Task TestCleanup()
    {
        await Context.Tracing.StopAsync(new()
        {
            Path = Path.Combine(
                Environment.CurrentDirectory,
                "playwright-traces",
                $"{TestContext.CurrentContext.Test.ClassName}.{TestContext.CurrentContext.Test.Name}.zip"
            )
        });
    }

    [TestMethod]
    public async Task GetStartedLink()
    {
        // ...
    }
}
```

</TabItem>
</Tabs>

This will record a zip file for each test, e.g. `PlaywrightTests.ExampleTest.GetStartedLink.zip` and place it into the `bin/Debug/net8.0/playwright-traces/` directory.

## Opening the trace

You can open the saved trace using the Playwright CLI or in your browser on [`trace.playwright.dev`](https://trace.playwright.dev). Make sure to add the full path to where your trace's zip file is located. Once opened you can click on each action or use the timeline to see the state of the page before and after each action. You can also inspect the log, source and network during each step of the test. The trace viewer creates a DOM snapshot so you can fully interact with it, open devtools etc.

```bash java
mvn exec:java -e -D exec.mainClass=com.microsoft.playwright.CLI -D exec.args="show-trace trace.zip"
```

```bash python
playwright show-trace trace.zip
```

```bash csharp
pwsh bin/Debug/net8.0/playwright.ps1 show-trace bin/Debug/net8.0/playwright-traces/PlaywrightTests.ExampleTest.GetStartedLink.zip
```

######
* langs: python, java

![playwright trace viewer](https://github.com/microsoft/playwright/assets/13063165/10fe3585-8401-4051-b1c2-b2e92ac4c274)

######
* langs: csharp

![playwright trace viewer dotnet](https://github.com/microsoft/playwright/assets/13063165/4372d661-5bfa-4e1f-be65-0d2fe165a75c)

To learn more check out our detailed guide on [Trace Viewer](/trace-viewer.md).

## What's next

- [Run tests on CI with GitHub Actions](/ci-intro.md)
- [Learn more about Trace Viewer](/trace-viewer.md)