# Identifying and avoiding harmful PrestaShop modules

> Check PrestaShop modules before installing them and avoid the kinds that often slow down, break or put your store at risk.

Source: https://helpcenter.ruachost.com/apps/prestashop/identifying-and-avoiding-harmful-prestashop-modules/

While most PrestaShop modules are safe and useful, some can negatively affect your site’s **performance, stability, or security**. On **ruachost.com**, it’s important to carefully evaluate modules before installing them.

## Why Be Careful with Modules?

- Poorly designed modules can slow down your site.
- Some modules may introduce security vulnerabilities.
- Excessive logging or resource‑intensive features can overload servers.
- Modules with no reviews or support may be unreliable.

## General Recommendations

- Research a module’s reputation before installing.
- Check online reviews and community feedback.
- Search for issues using terms like:

  - `"module name issues"`
  - `"module name performance"`
  - `"module name security"`
- If suspicious, look for alternative modules with better support.

## ⚠️ Common Types of Harmful Modules

### 1. Image Manipulation Modules

- Performing bulk image resizing or cropping directly on the server can overload processors.
- **Best practice:** Resize images locally before uploading.
- Modules that optimize images once at upload are generally safe.

### 2. Related Products / Related Posts Modules

- Some modules generate related content dynamically every time a page loads.
- This can significantly slow down page performance.
- **Best practice:** Use modules that pre‑process related products in batches and cache results.

### 3. Audit Logging Modules

- Logging every single site activity into the database creates huge tables.
- This slows down both the site and the server.
- **Best practice:** Limit the amount of data logged and purge old logs regularly.

## Important Notes

- Harmful modules are not always malicious, they may simply be poorly optimized.
- Always back up your site before installing new modules.
- If performance issues arise, disable suspicious modules and monitor improvements.