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Correlation matrix

See which number columns rise and fall together. Free, private and browser-based.

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Free workspace supports five open files. Each file can be up to 100 MB.

About the Correlation matrix

Open a CSV or Excel file to see how every pair of number columns moves together, from −1 (one rises as the other falls) through 0 (no relationship) to +1 (they rise together). The matrix is colour-coded and the strongest pairs are explained in words.

How to use it

  1. Open or drop a CSV, XLS or XLSX file with two or more number columns.
  2. Choose Pearson (straight-line relationships) or Spearman (any steady rise or fall, and less affected by outliers).
  3. Read the strongest pairs, hover a cell for the number of rows used, and download the matrix as CSV.

Tip: A strong correlation shows two things move together, not that one causes the other — a third thing may drive both.

Questions

Pearson or Spearman?

Pearson measures how well a straight line fits. Spearman compares ranks, so it also catches curved but steady relationships and is less thrown by outliers.

What counts as a strong correlation?

Roughly: above 0.8 very strong, 0.6–0.8 strong, 0.4–0.6 moderate, 0.2–0.4 weak, and below 0.2 very weak or none (the same for negative values).

What about empty cells?

Each pair uses only the rows where both columns have a number, and shows how many rows that was.

Is my data uploaded?

No. The tool runs in your browser; what you paste or open never leaves your device and nothing is stored on a server.