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Outlier Detector (1.5 IQR Rule)

Spot values that sit far outside the rest of your data using the classic Tukey fence method. Paste your numbers and the tool computes the first and third quartiles, sets the lower fence at Q1 minus one and a half times the interquartile range and the upper fence at Q3 plus the same amount, then lists any values beyond those fences as outliers. This is the exact rule box plots use to draw their whiskers, so points shown separately on a box plot are the ones flagged here. Removing or investigating outliers matters before you compute a mean or fit a model, since a few extreme points can distort results badly. The tool also shows the fence boundaries and the cleaned data so you can decide what to keep. Everything is computed locally in your browser, so your data stays on your device.

How to use Outlier Detector (1.5 IQR)

  1. Paste your data set.
  2. Submit to run the 1.5 IQR rule.
  3. Read the outliers, the fences and the clean values.

Frequently asked questions

How does the 1.5 IQR rule find outliers?

It flags any value below Q1 minus 1.5 times the IQR or above Q3 plus 1.5 times the IQR as an outlier.

What are the fence boundaries?

The fences are the lower and upper cutoffs from the 1.5 IQR rule, and any value outside them is treated as an outlier.

What are the clean values?

The clean values are the numbers that fall within the fences after the outliers are removed.

What is Outlier Detector (1.5 IQR)?

Spot values that sit far outside the rest of your data using the classic Tukey fence method. Paste your numbers and the tool computes the first and third quartiles, sets the lower fence at Q1 minus one and a half times the interquartile range and the upper fence at Q3 plus the same amount, then lists any values beyond those fences as outliers.

Is Outlier Detector (1.5 IQR) free to use?

Yes. Outlier Detector (1.5 IQR) is completely free, with no sign-up and no usage limits.

Does Outlier Detector (1.5 IQR) work in a web browser?

Yes. Outlier Detector (1.5 IQR) runs in any modern web browser. There is nothing to download or install.

Is my data private with Outlier Detector (1.5 IQR)?

Yes. Outlier Detector (1.5 IQR) runs entirely on your device in your browser, so nothing you enter is uploaded to a server.