Responsive Breakpoint Visual Diff

Render a URL at multiple viewport widths and inspect screenshots, pixel-difference heatmaps, and layout metrics in the page.

html· HTML resultOpen tool

Quick start

Call this tool from your code in three languages.

cURL

curl -X POST 'https://api.elysiatools.com/en/api/tools/responsive-breakpoint-diff' \
  -H 'Content-Type: application/json' \
  -d '{"url":"data:text/html,<!doctype html><style>body{margin:0;font-family:sans-serif}.grid{display:flex;gap:12px;padding:20px}.card{width:180px;height:90px;background:tomato}@media(max-width:500px){.grid{display:block}.card{width:100%;margin-bottom:12px;background:teal}}</style><main class=grid><div class=card>One</div><div class=card>Two</div></main>","viewportWidths":"375,768","viewportHeight":320,"waitMilliseconds":0,"comparisonMode":"adjacent"}'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST https://api.elysiatools.com/en/api/tools/responsive-breakpoint-diff

Parameters

Name	Type	Required	Description
url	text	Yes	—
viewportWidths	text	Yes	—
viewportHeight	number	No	—
waitMilliseconds	number	No	—
comparisonMode	select	No	—

Response format

HTML result

JSON

{
  "result": "<div>Processed HTML content</div>",
  "error": "Error message (optional)",
  "message": "Notification message (optional)",
  "metadata": {
    "key": "value"
  }
}

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-responsive-breakpoint-diff": {
      "name": "responsive-breakpoint-diff",
      "description": "Render a URL at multiple viewport widths and inspect screenshots, pixel-difference heatmaps, and layout metrics in the page.",
      "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=responsive-breakpoint-diff",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "responsive-breakpoint-diff",
    "arguments": {
  "url": "data:text/html,<!doctype html><style>body{margin:0;font-family:sans-serif}.grid{display:flex;gap:12px;padding:20px}.card{width:180px;height:90px;background:tomato}@media(max-width:500px){.grid{display:block}.card{width:100%;margin-bottom:12px;background:teal}}</style><main class=grid><div class=card>One</div><div class=card>Two</div></main>",
  "viewportWidths": "375,768",
  "viewportHeight": 320,
  "waitMilliseconds": 0,
  "comparisonMode": "adjacent"
}
  }
}

Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).

Questions or issues? Contact [email protected]