# Compare Screenshots to a Baseline, Flag Changes

**Use case:** 

Check UI screenshots against a baseline build and flag which ones changed. Rows show similarityScore, phashDistance, and a verdict per screenshot.

## Input

```json
{
  "sourceImage": "https://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/LibreOffice_7.0_Start_Center.png/960px-LibreOffice_7.0_Start_Center.png",
  "targetImages": [
    {
      "url": "https://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/LibreOffice_7.0_Start_Center.png/500px-LibreOffice_7.0_Start_Center.png",
      "customId": "build-1042"
    },
    {
      "url": "https://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/LibreOffice_6.4.2_Start_Page_for_Windows_10.png/960px-LibreOffice_6.4.2_Start_Page_for_Windows_10.png",
      "customId": "build-1043"
    },
    {
      "url": "https://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/LibreOffice_7.1.4_Calc_Japanese.png/960px-LibreOffice_7.1.4_Calc_Japanese.png",
      "customId": "build-1044"
    }
  ],
  "comparisonMode": "both",
  "threshold": 0.95,
  "phashThreshold": 8
}
```

## Output

```json
{
  "targetIndex": {
    "label": "Target index",
    "format": "integer"
  },
  "targetImage": {
    "label": "Target image",
    "format": "string"
  },
  "similarityScore": {
    "label": "Similarity score",
    "format": "number"
  },
  "phashDistance": {
    "label": "pHash distance",
    "format": "integer"
  },
  "verdict": {
    "label": "Verdict",
    "format": "string"
  },
  "isSimilar": {
    "label": "Is similar",
    "format": "boolean"
  },
  "isNearDuplicate": {
    "label": "Is near duplicate",
    "format": "boolean"
  },
  "customId": {
    "label": "Custom ID",
    "format": "string"
  },
  "errorMessage": {
    "label": "Error message",
    "format": "string"
  }
}
```

## About this Actor

This example demonstrates how to use [Image Similarity API | Compare Images, Find Duplicates](https://apify.com/johnvc/image-similarity-api) with a specific input configuration. Visit the [Actor detail page](https://apify.com/johnvc/image-similarity-api) to learn more, explore other use cases, and run it yourself.


## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
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This Task's input is already configured above — use it as-is rather than inventing a new one.

- **AI agents and MCP clients** — the [Apify MCP server](https://docs.apify.com/integrations/mcp.md) at `https://mcp.apify.com` (remote, streamable HTTP, OAuth on first use).
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For full API examples (JavaScript, Python, CLI, MCP, OpenAPI), see this Task's Actor page: https://apify.com/johnvc/image-similarity-api.md

For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt).