CrUX performance report
All Devices
- Class
- Field metrics
- Term
- Loading…
| Subject | p75 | Good | Mark |
|---|---|---|---|
LCP | |||
CLS | |||
INP | |||
FCP | |||
TTFB |
Official field transcript
Web performance report
Performance analysis for web.dev
Term: Loading…
CrUX performance report
Desktop
- Class
- Field metrics
- Term
- Loading…
| Subject | p75 | Good | Mark |
|---|---|---|---|
LCP | |||
CLS | |||
INP | |||
FCP | |||
TTFB |
CrUX performance report
Mobile
- Class
- Field metrics
- Term
- Loading…
| Subject | p75 | Good | Mark |
|---|---|---|---|
LCP | |||
CLS | |||
INP | |||
FCP | |||
TTFB |
CrUX performance report
Tablet
- Class
- Field metrics
- Term
- Loading…
| Subject | p75 | Good | Mark |
|---|---|---|---|
LCP | |||
CLS | |||
INP | |||
FCP | |||
TTFB |
How Scores Are Calculated
Understanding the performance metrics and scoring methodology
The overall performance score is calculated based on the percentage of "Good" experiences for each Core Web Vital and other performance metrics. Data is collected from real users through the Chrome User Experience Report (CrUX).
Score Weighting
LCP
30% of score
CLS
25% of score
INP
20% of score
FCP
15% of score
TTFB
10% of score
Grading System
For each metric, we calculate the percentage of users experiencing "Good" performance. These percentages are then weighted according to the importance of each metric and combined to create an overall score out of 100, which is converted to a letter grade.
A+ (95-100)
Exceptional
A (90-94)
Excellent
B+ (85-89)
Very Good
B (80-84)
Good
C+ (75-79)
Satisfactory
C (70-74)
Adequate
D (60-69)
Needs Improvement
F (0-59)
Poor
Example Calculation:
If 80% of users have good LCP, 70% have good CLS, 60% have good INP, 90% have good FCP, and 75% have good TTFB:
Score = (80 * 0.3) + (70 * 0.25) + (60 * 0.2) + (90 * 0.15) + (75 * 0.1) = 74.5
Rounded to the nearest integer: 75 (Grade: C+)
Metric Thresholds
Largest Contentful Paint (LCP)Good: <= 2.5s, Needs Improvement: <= 4.0s, Poor: > 4.0s
Cumulative Layout Shift (CLS)Good: <= 0.1, Needs Improvement: <= 0.25, Poor: > 0.25
Interaction to Next Paint (INP)Good: <= 200ms, Needs Improvement: <= 500ms, Poor: > 500ms
First Contentful Paint (FCP)Good: <= 1.8s, Needs Improvement: <= 3.0s, Poor: > 3.0s
Time to First Byte (TTFB)Good: <= 0.8s, Needs Improvement: <= 1.8s, Poor: > 1.8s
Data Collection
Performance data is collected from real users via the Chrome User Experience Report (CrUX). The data represents the 75th percentile of user experiences over the past 28 days, meaning 75% of users experienced performance that was the same or better than the reported metrics.