# Web Compare: Side-by-Side URL Comparison

> Web Compare: Side-by-Side URL Comparison is a paid API for AI agents from cr4vvol.vercel.app, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).

Fetches and compares the content of two web pages, returning a structured diff or comparison of their content

## Facts

- Endpoint: POST https://cr4vvol.vercel.app/api/compare
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/web-compare-side-by-side-url-comparison-4749a1e8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_f2ExAgdX90xHjyoLMJFA5

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability web-compare-side-by-side-url-comparison-4749a1e8 -d '<json body>'
```

Example prompt: Can you compare these two product pages and tell me what's different between them: https://example.com/product-v1 and https://example.com/product-v2?

## When to prefer this

Use this endpoint when you need to programmatically compare the content of two web pages without setting up auth or subscriptions — pay-per-use via USDC makes it ideal for one-off or low-frequency comparisons. Best for agents that need to detect changes, differences, or similarities between two live URLs on demand.

## Known failure modes

- One or both URLs are unreachable or return non-200 status — comparison may fail or return partial data
- URLs point to non-HTML content (PDFs, images) — extraction may fail or return unexpected results
- Payment of $0.05 USDC via x402 not completed — request rejected
- Malformed or missing urlA/urlB parameters — validation error
- Target pages block scrapers via bot detection — content may be incomplete

## How this service works

Web scraping and search for AI agents. No auth, no subscriptions. Pay per request in USDC via x402.

## Output

Returns a JSON object with a 'success' boolean and a 'data' object containing the comparison results between the two fetched URLs, likely including extracted content and differences between the two pages.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "urlA",
  "urlB"
 ],
 "properties": {
  "urlA": {
   "type": "string",
   "description": "First URL"
  },
  "urlB": {
   "type": "string",
   "description": "Second URL"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "type": "object"
  },
  "success": {
   "type": "boolean"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/web-compare-side-by-side-url-comparison-4749a1e8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from cr4vvol.vercel.app](https://www.zero.xyz/host/cr4vvol.vercel.app/llms.txt)