Box Plot Maker

Paste values to calculate quartiles, whiskers, outliers, and render an SVG box plot that can be downloaded.

Wave124 · multi-group distribution audit + local export

Box Plot & Distribution Audit Studio

Build one or many box-and-whisker plots without hiding the quartile convention. Import local spreadsheet data, compare distributions, inspect IQR fences and actual whisker observations, surface raw points and mean/notch cues, then export the chart together with the statistics that produced it.

CSV · TSV · JSON · XLSXUp to 12 groups2 quartile conventions1.5× / 3× IQR fencesRaw points · mean · approximate notchesSVG · 2× PNG · CSV · Project JSON

1 · Load or edit groups

Paste grouped data

2 · Statistical method

Quartile methodIQR fenceOrientationStyle preset

3 · Editorial labels

Chart titleValue axis

Groups—

Total n—

Potential outliers—

Highest median—

Distribution/readability audit

Reproducible statistics table

Keep the quartiles and actual whisker observations with the chart. A box plot can flag unusual observations but does not determine whether a point is erroneous or should be removed.

Group	n	Min	Q1	Median	Q3	Max	Mean	Sample SD	IQR	Whiskers	Outliers

Quartile methods differ

Linear interpolation matches a common spreadsheet percentile convention. Median-of-halves can produce different Q1/Q3 values, especially in small samples. The selected method is preserved in exports.

Tukey-style fences are flags

Whiskers end at the most extreme observations still inside the selected IQR fences. Values beyond a fence are potential outliers for review, not automatic errors.

Notches are approximate

The optional notch uses median ± 1.58 × IQR / √n as a visual uncertainty cue. Treat it as exploratory, especially for small or irregular samples.

Privacy and persistence

Imported CSV/XLSX data is parsed in this browser. Local snapshots stay in browser storage. Settings-only links exclude data, titles, colors and snapshots.

Accessible / reproducible summary

Statistical boundary. This Studio computes descriptive summaries from the values you provide. Quartile definitions vary across software, IQR fences are exploratory flags rather than proof of bad data, and apparent group differences do not establish statistical significance or causation. Preserve the sampling design and domain context with any exported figure.

Ready. Chart data stays in this browser unless you intentionally export it.

Focused box-and-whisker workflow with visible method evidence

Paste grouped data or import CSV/XLSX, choose the quartile convention and IQR fence, inspect the actual whisker endpoints and flagged observations, then export the SVG/PNG together with the summary CSV. The chart and numeric evidence stay connected instead of turning quartiles into a black box.

Why the method is shown

NIST describes box plots using the median, lower and upper quartiles, IQR and optional 1.5×/3× IQR fences. Software can still differ in how quartiles are estimated, so WebToolArc exposes the convention rather than implying one universal answer.

Compare groups without hiding raw data

Use raw-point overlays, mean markers or approximate notches as optional context. For crowded groups, export the summary and switch to a distribution-focused analysis rather than forcing every conclusion into the box shape.