Free Online Data Tools

Prepare CSV and JSON records, calculate numeric matrices and inspect graph data with free online data tools.

Choose the right tool

Use CSV conversion for changing representation, a keyed join for combining tables, and reconciliation for checking differences. Match header names and review keys before comparing exports; keep identifiers with leading zeros as text. Matrix inputs are JSON numeric rows; graph inputs use the documented edge-list direction and weights.

Available tools

• CSV Viewer & Editor

  View and edit CSV cells in a local table, then export changes.

• TSV ↔ CSV Converter

  Convert tab-separated and comma-separated tables with proper quoting.

• CSV Column Selector

  Select columns by their exact header names.

• CSV Row Filter

  Keep rows where the selected column contains your text.

• CSV Duplicate Row Remover

  Remove identical data rows while preserving the header.

• Merge CSV Files

  Merge two CSV tables with identical headers.

• CSV to HTML Table

  Generate an escaped HTML table from CSV.

• JSON to SQL INSERT Statements

  Generate INSERT statements for flat records using the selected dialect.

• CSV File Comparison

  Compare two CSV tables using a unique key column; report added, removed and changed rows.

• Fixed-Width Text to JSON

  Convert fixed-width text using named character lengths; preserve leading zeros.

• Text File Encoding Converter

  Decode UTF-8, Windows-1252, ISO-8859-1 (HTML mapping) or UTF-16 and export UTF-8 or UTF-16.

• JSON Fields to CSV

  Extract JSON Pointer fields from each array item into a CSV table.

• Transpose CSV

  Swap CSV rows and columns, treating the first row as ordinary cells.

• Rename CSV Columns

  Rename selected headers using a JSON name map.

• Add CSV Column

  Append a constant-valued column to every CSV data row.

• Remove Empty CSV Rows

  Remove data rows whose cells are all empty or whitespace-only.

• Sort CSV Rows

  Sort CSV data rows by an exact column using text or numeric comparison.

• CSV Grouped Sum

  Group CSV rows by a text column and sum a numeric column.

• Join CSV Tables

  Join two CSV tables by unique, non-empty keys with inner, left or full joins.

• CSV Amount Reconciliation

  Reconcile two exports by unique key and exact two-decimal amounts; report missing IDs and deltas.

• CSV to Markdown Table

  Convert a CSV table to Markdown, escaping table delimiters and cell markup.

• CSV Column Statistics

  Calculate numeric statistics for a selected CSV column.

• CSV Table Profile

  Inspect column completeness, distinct values and numeric coverage.

• Fill Blank CSV Cells

  Replace exactly empty cells with a supplied value.

• Trim CSV Cell Whitespace

  Remove leading and trailing whitespace from data cells.

• Split CSV Column

  Expand a delimiter-separated column into numbered fields.

• Combine CSV Columns

  Append a field assembled from selected source columns.

• CSV Row Number Generator

  Append sequential row numbers without changing the source fields.

• CSV Row Range Extractor

  Keep an inclusive range of data rows and the header.

• CSV Cell Find and Replace

  Replace literal text inside data cells, leaving headers unchanged.

• Normalize CSV Headers

  Convert headers to lowercase underscore names and detect collisions.

• CSV Unique Column Values

  Extract distinct values from one column in first-seen order.

• CSV Column Value Counts

  Count records for every distinct column value.

• CSV Count Crosstab

  Count records at each pair of category values.

• CSV Unpivot to Long Format

  Turn non-key columns into variable and value records.

• CSV Cartesian Join

  Create every pairing of records from two CSV tables.

• CSV Missing Key Report

  Find records whose key is absent from the reference CSV.

• CSV Running Total

  Append a cumulative total for a numeric column.

• CSV Moving Average

  Append a trailing average using complete windows only.

• Round CSV Numeric Column

  Round one numeric column to a fixed decimal precision.

• Scale CSV Numeric Column

  Multiply each numeric value in a column by a fixed factor.

• CSV Percentage of Total

  Append each record’s percentage share of a numeric column total.

• CSV Numeric Rank

  Append descending competition ranks; equal values share a rank.

• CSV Forward Fill

  Fill empty cells from the most recent non-empty value in their column.

• Reverse CSV Data Rows

  Reverse record order while keeping the header first.

• CSV Row Character Report

  Append the combined text length of each record’s fields.

• Remove Empty CSV Columns

  Drop columns whose data cells are all empty.

• CSV Constant Column Report

  Identify fields that hold one identical value across all records.

• CSV Required Field Checker

  Report data rows with missing or whitespace-only required fields.

• CSV Numeric Validation Report

  Report cells in one column that are not valid finite decimal numbers.

• CSV Duplicate Key Report

  Report repeated key values and their data-row numbers.

• CSV Every Nth Record

  Extract every Nth data record from a specified starting row.

• CSV Backward Fill

  Fill empty cells from the next non-empty cell below in each column.

• CSV Incomplete Record Remover

  Remove rows with an empty or whitespace-only selected field.

• CSV Text Column Case Converter

  Change case in one selected data column without affecting other cells.

• CSV Category Mapping Applier

  Replace exact column values using an explicit JSON string dictionary.

• CSV Numeric Binner

  Append a numeric interval label for a chosen column.

• CSV Grouped Running Total

  Append per-group cumulative sums in original row order.

• CSV Lag and Lead Column

  Append an offset value from another row in the same column.

• CSV Numeric Difference Column

  Append each numeric value’s change from its previous row.

• CSV Column Z-Score Standardizer

  Append population-standardized values for a numeric column.

• CSV Min-Max Normalizer

  Append numeric values rescaled to the interval zero through one.

• CSV Numeric Winsorizer

  Clamp selected numeric column values to explicit lower and upper limits.

• CSV IQR Outlier Report

  Report numeric rows outside Tukey’s 1.5-IQR fences.

• CSV Top Records per Group

  Keep the highest N numeric records within each group.

• CSV Head and Tail Preview

  Return the first and last N records with no duplicated overlap.

• CSV Record Chunker

  Divide a table into separate CSV strings that each retain the header.

• CSV Numeric Column Detector

  Identify columns whose non-empty data cells are all finite decimal numbers.

• CSV ISO Date Column Checker

  Validate YYYY-MM-DD values in a selected CSV column.

• CSV Boolean Value Normalizer

  Normalize explicit true/false, yes/no and 1/0 tokens in one column.

• CSV Numeric Matrix Extractor

  Extract numeric data cells as a JSON matrix, omitting headers.

• CSV Numeric Total Row Appender

  Append totals for numeric columns and a label for the first field.

• CSV Spreadsheet Formula Neutralizer

  Prefix potentially executable spreadsheet formula cells with an apostrophe.

• CSV Multi-Column Sorter

  Sort records lexically by multiple columns in priority order.

• CSV Two-Column Arithmetic

  Append the sum, difference, product or quotient of two numeric fields.

• CSV Grouped Numeric Summary

  Summarize count, sum, mean, minimum and maximum for each group.

• CSV Composite Key Builder

  Append an unambiguous serialized key from chosen columns.

• Elementwise Matrix Calculator

  Apply elementwise arithmetic to two equal-size matrices.

• Matrix Multiplication Calculator

  Multiply compatible numeric matrices using dot products.

• Integer Matrix Power Calculator

  Raise a square matrix to a non-negative integer power by repeated squaring.

• Matrix Determinant Calculator

  Compute a determinant by pivoted elimination.

• Matrix Inverse Calculator

  Invert a nonsingular square matrix using Gauss-Jordan elimination.

• Reduced Row Echelon Form Calculator

  Return reduced row echelon form and estimated matrix rank.

• Matrix Trace Calculator

  Sum the main diagonal entries of a square matrix.

• Matrix Norm Calculator

  Calculate Frobenius, maximum column-sum and maximum row-sum norms.

• Matrix Vectorization Tool

  Flatten a matrix in row-major or column-major order.

• Matrix Row and Column Totals

  Calculate row sums, column sums and the grand total.

• Matrix Row Probability Normalizer

  Normalize each non-negative row to a total of one.

• Matrix Diagonal Extractor

  Extract main and anti-diagonals from a square matrix.

• Triangular Matrix Extractor

  Keep the upper or lower triangle of a square matrix.

• Matrix Symmetry Checker

  Check square matrices for symmetry and skew-symmetry within a tolerance.

• Cholesky Decomposition Calculator

  Factor a symmetric positive-definite matrix into L × Lᵀ.

• 2×2 Matrix Eigenvalue Calculator

  Find real or complex-conjugate eigenvalues of a 2×2 matrix.

• Kronecker Product Calculator

  Build the block tensor product of two small matrices.

• 2D Numeric Cross-Correlation

  Apply a numeric kernel to a matrix using valid-only placement.

• Numeric Matrix Rotation Tool

  Rotate a rectangular matrix by a right angle clockwise or counterclockwise.

• Linear System Matrix Solver

  Solve A×x=b for a bounded nonsingular square coefficient matrix.

• Sample Covariance Matrix Calculator

  Calculate sample covariance between columns of observation rows.

• Pearson Correlation Matrix Calculator

  Calculate Pearson correlations between numeric columns.

• Pairwise Euclidean Distance Matrix

  Calculate distances between every pair of observation rows.

• Matrix Column Standardizer

  Center each column and divide by its population standard deviation.

• Graph Adjacency List Builder

  Convert an edge list into named outgoing adjacency lists.

• Graph Adjacency Matrix Builder

  Build a weighted adjacency matrix with null for absent edges.

• Graph BFS and DFS Traversal

  Visit reachable nodes from a selected source using breadth-first or depth-first order.

• Nonnegative Shortest Path Calculator

  Find shortest directed path distances from one source using Dijkstra’s algorithm.

• Dependency Topological Sorter

  Order a directed acyclic dependency graph and reject cycles.

• Undirected Connected Component Finder

  Group nodes connected when edge directions are ignored.

• Minimum Spanning Forest Calculator

  Choose a minimum-weight undirected spanning forest using Kruskal’s algorithm.

• All-Pairs Shortest Distance Calculator

  Compute directed all-pairs distances with Floyd-Warshall and detect negative cycles.

• Graph Node Degree Report

  Report incoming, outgoing and total edge incidence by named node.

• Graph Reachability Matrix

  Compute whether every ordered node pair is connected by a directed path.

• JSON Power Set Generator

  Generate every subset of at most 12 distinct serialized array values.

• Distinct Array Permutation Generator

  Generate distinct orderings of up to eight JSON values.

• Integer Subset Sum Finder

  Find one subset of a small non-negative integer list matching a target.

• 0/1 Knapsack Solver

  Choose each item at most once to maximize value within an integer capacity.

• Numeric Interval Set Calculator

  Merge closed intervals or calculate intersection between two interval sets.

• Maximum Non-Overlapping Interval Selector

  Select the maximum count of compatible half-open intervals using earliest finish order.

• First-Fit Decreasing Bin Packer

  Pack positive sizes into fixed-capacity bins using a documented heuristic.

• Longest Increasing Subsequence Finder

  Find one strictly increasing subsequence of maximum length.

• Longest Common Token Subsequence

  Find a longest shared ordered subsequence between two small JSON arrays.

• Numeric Trend Segment Finder

  Split a numeric sequence at changes between rising, falling and equal steps.