Data Science & Analytics 100% Local Processing Limit: 20,000 data points

Z-Score & IQR Statistical Outlier Detector

Detect anomalous data points and anomalies in numerical distributions using Interquartile Range (IQR) fences and Standard Z-Scores.

Sponsor Space

1. Dataset & Detection Rule

2. Outlier Analysis

Detected Anomalies:
Q1 (25th percentile): --
Q3 (75th percentile): --
IQR Spread: --
Mean (μ): --
Lower Fence: --
Upper Fence: --
Sponsor Space

How to Use the Z-Score & IQR Statistical Outlier Detector

  1. 1
    Paste numbers separated by commas, spaces, or newlines.
  2. 2
    Select your outlier detection method: IQR (Tukey's 1.5×IQR Rule) or Z-Score (|z| > 2.5 or 3.0 threshold).
  3. 3
    Examine the computed summary metrics: Q1, Q3, IQR, Lower Fence, Upper Fence, Mean, and Standard Deviation.
  4. 4
    View highlighted anomalous values and download or copy the clean outlier-free dataset.

Practical Example & Use Case

Common Real-World Scenario

Detecting anomalous transaction amounts or server latency spikes in a sample distribution.

Technical Notes & Limitations

Browser Engine Architecture

Computes standard parametric (Z-score) and non-parametric (Tukey IQR) anomaly boundaries in browser memory.

Frequently Asked Questions

When should I use IQR versus Z-Score for outlier detection?

Use IQR when your data is skewed or has heavy tails (non-normal); use Z-Score when your data is roughly normally distributed.