---
title: Understanding Performance Grade
description: "The performance grade (0-100%) is calculated based on multiple factors: - Load time > 3s: -5 points per second over - TTFB > 600ms: -10 points - Page size > 2MB: -5 points per MB over - Requests > 50:…"
url: "https://ssh-assistant.com/docs/understanding-performance-grade/"
updated: "2025-12-07"
category: Site Load Tester / Speed Tester
---

# Understanding Performance Grade

The performance grade (0-100%) is calculated based on multiple factors:

- Load time > 3s: -5 points per second over
- TTFB > 600ms: -10 points
- Page size > 2MB: -5 points per MB over
- Requests > 50: -1 point per 10 requests over
- No compression: -10 points
- No caching headers: -5 points

## Best Practices

**Optimize Images:** Use modern formats (WebP, AVIF), compress images, and serve appropriately sized images for each device.

**Enable Compression:** Enable gzip or brotli compression on your server to reduce file sizes.

**Minimize HTTP Requests:** Bundle CSS and JavaScript files, use CSS sprites, and reduce external resources.

**Use Caching:** Set appropriate Cache-Control headers for static assets to reduce repeated downloads.

**Optimize JavaScript:** Code split, lazy load, and minify JavaScript. Avoid blocking the main thread with heavy operations.

**Use a CDN:** Serve static assets from a Content Delivery Network closer to your users.

#### Limitations

- Cannot measure visual rendering or JavaScript execution time

- May not capture all lazy-loaded resources

- Results vary based on your network connection speed

- Tests run from your machine, not a remote server