playwright/docs/src/api/class-snapshotassertions.md

class: SnapshotAssertions

• since: v1.20
• langs: js

:::tip For visual regression testing, use [method: PageAssertions.toHaveScreenshot#1] and [method: LocatorAssertions.toHaveScreenshot#1] instead. :::

Playwright provides methods for comparing text values with expected values stored in snapshot files.

expect(text).toMatchSnapshot('snapshot.txt');

method: SnapshotAssertions.toMatchSnapshot#1

• since: v1.22

Ensures that the passed [string] matches the expected snapshot stored in the test snapshots directory.

Usage

// Basic usage.
expect(await page.title()).toMatchSnapshot('page-title.txt');

// Bring some structure to your snapshot files by passing file path segments.
expect(await page.title()).toMatchSnapshot(['page-title', 'step1.txt']);
expect(await page.title()).toMatchSnapshot(['page-title', 'step2.txt']);

Note that matching snapshots only work with Playwright test runner.

param: SnapshotAssertions.toMatchSnapshot#1.name

• since: v1.22

• name <[string]|[Array]<[string]>>

Snapshot name.

method: SnapshotAssertions.toMatchSnapshot#2

• since: v1.22

Ensures that passed value, either a [string] or a [Buffer], matches the expected snapshot stored in the test snapshots directory.

Usage

// Basic usage.
expect(await page.title()).toMatchSnapshot();

// Configure the snapshot name.
expect(await page.title()).toMatchSnapshot({
  name: 'page-title.txt',
});

Note that matching snapshots only work with Playwright test runner.

option: SnapshotAssertions.toMatchSnapshot#2.name

• since: v1.22

• name <[string]|[Array]<[string]>>

Snapshot name. If not passed, the test name and ordinals are used when called multiple times.

method: SnapshotAssertions.toMatchSnapshot#3

• deprecated: To avoid flakiness, use [method: PageAssertions.toHaveScreenshot#1] instead.
• since: v1.22

Ensures that the passed [Buffer] matches the expected snapshot stored in the test snapshots directory.

Usage

// Basic usage.
expect(await page.screenshot()).toMatchSnapshot('landing-page.png');

// Pass options to customize the snapshot comparison and have a generated name.
expect(await page.screenshot()).toMatchSnapshot('landing-page.png', {
  maxDiffPixels: 27, // allow no more than 27 different pixels.
});

// Configure image matching threshold.
expect(await page.screenshot()).toMatchSnapshot('landing-page.png', { threshold: 0.3 });

// Bring some structure to your snapshot files by passing file path segments.
expect(await page.screenshot()).toMatchSnapshot(['landing', 'step2.png']);
expect(await page.screenshot()).toMatchSnapshot(['landing', 'step3.png']);

Learn more about visual comparisons.

Note that matching snapshots only work with Playwright test runner.

param: SnapshotAssertions.toMatchSnapshot#3.name

• since: v1.22

• name <[string]|[Array]<[string]>>

Snapshot name.

option: SnapshotAssertions.toMatchSnapshot#3.maxDiffPixels = %%-assertions-max-diff-pixels-%%

• since: v1.22

option: SnapshotAssertions.toMatchSnapshot#3.maxDiffPixelRatio = %%-assertions-max-diff-pixel-ratio-%%

• since: v1.22

option: SnapshotAssertions.toMatchSnapshot#3.threshold = %%-assertions-threshold-%%

• since: v1.22

method: SnapshotAssertions.toMatchSnapshot#4

• deprecated: To avoid flakiness, use [method: PageAssertions.toHaveScreenshot#1] instead.
• since: v1.22

Ensures that the passed [Buffer] matches the expected snapshot stored in the test snapshots directory.

Usage

// Basic usage and the file name is derived from the test name.
expect(await page.screenshot()).toMatchSnapshot();

// Pass options to customize the snapshot comparison and have a generated name.
expect(await page.screenshot()).toMatchSnapshot({
  maxDiffPixels: 27, // allow no more than 27 different pixels.
});

// Configure image matching threshold and snapshot name.
expect(await page.screenshot()).toMatchSnapshot({
  name: 'landing-page.png',
  threshold: 0.3,
});

Learn more about visual comparisons.

Note that matching snapshots only work with Playwright test runner.

option: SnapshotAssertions.toMatchSnapshot#4.maxDiffPixels = %%-assertions-max-diff-pixels-%%

• since: v1.22

option: SnapshotAssertions.toMatchSnapshot#4.maxDiffPixelRatio = %%-assertions-max-diff-pixel-ratio-%%

• since: v1.22

option: SnapshotAssertions.toMatchSnapshot#4.name

• since: v1.22

• name <[string]|[Array]<[string]>>

Snapshot name. If not passed, the test name and ordinals are used when called multiple times.

option: SnapshotAssertions.toMatchSnapshot#4.threshold = %%-assertions-threshold-%%

• since: v1.22