---
id: software-mansion/argent/argent-screenshot-diff
version: "0692cbfb"
license: Apache-2.0
install: manual
updated: 2026-07-27
---

# argent-screenshot-diff — This skill automates visual regression detection by analyzing differences between baseline and current application screenshots. It helps teams identify unintended UI changes early in development, preventing visual bugs from reaching production. Perfect for continuous integration pipelines that need reliable visual testing coverage.

Publisher: software-mansion · Stars: 1824 · Updated: 2026-07-27

Install (manual): `git clone https://github.com/software-mansion/argent`

## SKILL.md

## 1. Role

Use `screenshot-diff` as supporting visual evidence for UI QA and visual regression checks. It highlights pixel-visible change or stability; it does not replace visual inspection, accessibility/component-tree state, frame/attribute checks, logs, network evidence, or app behavior.

Do not use screenshot diffing for tap-coordinate discovery. Use `describe`, `debugger-component-tree`, or `native-describe-screen` to find targets first.

## 2. When To Use

Use `screenshot-diff` when pixel comparison can answer the verification question:

- Required for explicit "UI regression test", "visual regression test", "screenshot diff", "compare screenshots", or "before/after visual comparison" requests, unless stable comparable screenshots cannot be produced.
- Good fit when the affected screen has stable before/after states and the expected result is pixel-visible: layout, position, size, spacing, color, typography, image/icon rendering, clipping, overflow, or text rendering.
- Good fit when the risk is unintended visual regression outside the exact element changed.
- Poor fit when the result is better verified structurally: state changes, navigation existence, accessibility tree contents, console/network behavior, or unit tests.
- Poor fit when dynamic content, unpausable animation, timestamps, ads, random data, or missing baseline/current screenshots would make the comparison noisy or meaningless.

## 3. Capture Rules

Use normal downscaled `screenshot` calls for UI context and state checks. Use full-resolution screenshots only when saving baseline/current PNG files for visual regression comparison. Suppress the image block so the full-size PNG is not loaded into context:

```json
{ "udid": "<UDID>", "scale": 1.0, "includeImageInContext": false }
```

Capture the stable baseline before the relevant interaction or before editing whenever feasible. Compare it to the post-change or post-interaction screen after the app reloads, rebuilds, or reaches the state under test.

## 4. Parameters

Provide `udid` and exactly one input for the baseline side and exactly one input for the current side:

- Common UI regression flow: saved baseline plus live current -> `baselinePath`, `captureCurrent: true`, `udid`, `outputDir`.
- Both screenshots already saved -> `baselinePath`, `currentPath`, `udid`, `outputDir`.
- Rare fixture flow: live baseline plus saved current -> `captureBaseline: true`, `currentPath`, `udid`, `outputDir`.
- Do not combine `captureBaseline: true` with `captureCurrent: true`, or provide both a path and live capture flag for the same side.

## 5. Deterministic Flow

1. Navigate to the known-good state.
2. Capture a baseline PNG with `screenshot` using `scale: 1.0` and `includeImageInContext: false`; keep the returned `path`.
3. Perform the interaction, apply the code change and navigate to the state under test.
4. Call `screenshot-diff` with the saved `baselinePath`, `captureCurrent: true`, `udid`, and `outputDir`.
5. Inspect the summary and artifact paths, then combine the diff with normal visual inspection and any structural/runtime evidence needed for the assertion.

```json
{
  "baselinePath": "/tmp/baseline.png",
  "captureCurrent": true,
  "udid": "<UDID>",
  "outputDir": "/tmp/argent-diff"
}
```

If both images are already saved, use file paths for both sides:

```json
{
  "baselinePath": "/tmp/baseline.png",
  "currentPath": "/tmp/current.png",
  "udid": "<UDID>",
  "outputDir": "/tmp/argent-diff"
}
```


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