# File Checksum Monitoring

Source: PageCrawl.io Help Center
URL: https://pagecrawl.io/help/file-tracking/article/file-checksum-hash-monitoring

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File Checksum Monitoring detects when any online file has been modified by comparing its SHA-256 hash. Unlike text-based monitoring, this works with any file type, including zip archives, images, videos, and binary files. When a change is detected, the original file is stored so you can download and compare versions.

### What is SHA-256?

SHA-256 is a cryptographic hash function that produces a unique fingerprint for a file. If even a single byte changes, the hash changes completely, making it reliable for detecting modifications.

### How It Works

1. You provide the URL of the file to monitor
2. PageCrawl downloads the file and calculates its SHA-256 checksum
3. On each subsequent check, the checksum is recalculated and compared
4. If the checksum differs, you receive a notification
5. The previous version of the file is saved for manual comparison

### Setup

1. Click **Track New Page**
2. Paste the direct URL to the file
3. PageCrawl detects the file and shows checksum monitoring options
4. Choose your check frequency and notification preferences
5. Save

  [Image: When you paste a direct file URL (e.g. a .zip) into PageCrawl, it detects a file and selects File Checksum, since text cannot be extracted]

### Supported File Types

Any file accessible via URL, including: zip, rar, psd, video, audio, images, and more. Maximum file size is **15 MB**. Contact support if you need to monitor larger files.

### Checksum vs Text Monitoring

| Method | Best For | Shows Exact Changes |
|--------|----------|-------------------|
| **File checksum** | Any file type (binary, images, archives) | No, only that the file changed |
| **Text monitoring** | PDF, Excel, Word, CSV, PowerPoint | Yes, line-by-line diff |

If you need to see exactly what text changed in a document, use the dedicated text monitoring for [PDF](/help/file-tracking/article/can-pagecrawl-detect-changes-in-pdf.md), [Excel](/help/file-tracking/article/track-changes-in-excel-files.md), [Word](/help/file-tracking/article/track-changes-in-word-files.md), [CSV](/help/file-tracking/article/track-changes-in-csv-files.md), or [PowerPoint](/help/file-tracking/article/track-changes-in-powerpoint-files.md) files instead.

### FAQ

- **How often are files checked?** You can set the frequency from every 5 minutes to monthly, depending on your plan.
- **What if the file is no longer accessible?** You will be notified with an error status.
- **Can I stop monitoring a file?** Yes, disable or delete it at any time.

### Related Articles

- [PDF Changes](/help/file-tracking/article/can-pagecrawl-detect-changes-in-pdf.md) - Monitor PDF text changes
- [Excel Spreadsheets](/help/file-tracking/article/track-changes-in-excel-files.md) - Monitor spreadsheet text changes
- [Word Documents](/help/file-tracking/article/track-changes-in-word-files.md) - Monitor Word text changes

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