Data Visualiztion Tool

A free web application from PandaDev that helps users turn spreadsheets into interactive charts and downloadable reports. Users can import local files, review their structure, adjust how columns are interpreted, and explore their data through a readable interface.

The application processes spreadsheet content locally in the browser, without requiring an account, backend, database, or cloud storage. Features Spreadsheet Import and Preview Import CSV, TSV, XLSX, and XLS files, then review the data before creating a dashboard.

The import preview allows users to:

• Select a header row from the first 100 source rows.
• Skip introductory titles and other rows above the selected header.
• Review detected column types.
• Set individual columns to Auto detect, Text, or Number.
• Preserve text identifiers and leading zeros stored in text cells.
• Select file-wide or per-column number formats.
• Preview converted values before confirming the import.
• Choose worksheets from Excel workbooks. Supported numeric conventions include: Convention Example Decimal point with comma grouping 1,234.56 Decimal comma with point grouping 1.234,56 Decimal comma with space grouping 1 234,56

Numeric conversion checks cover the complete selected table. Invalid conversions block confirmation so users can correct the format or retain the column as text. Interactive Charts Create and customize seven visualization types:

• Bar charts
• Horizontal bar charts
• Line charts
• Area charts
• Pie charts
• Donut charts
• Radar charts Users can select grouping columns, numeric measures, chart titles, and calculations such as Total, Average, and Row count.

Numeric datasets start with four initial charts that users can edit, remove, or expand. Data Explorer Inspect spreadsheet records through a searchable table with:

• Search across columns
• Exact-value filters, including blank values
• Column sorting
• Pagination
• Visible filter indicators across dashboard views Applied filters also control the rows included in data exports. Data Quality Details Review the structure and completeness of the original dataset, including:
• Detected column types
• Unique-value counts
• Missing cells
• Overall completeness
• Duplicate rows Downloads and Layouts Export results in several formats: Format Contents CSV Filtered spreadsheet records Excel Filtered records in an XLSX workbook PNG Rendered dashboard image PDF Rendered dashboard report JSON Reusable chart configuration

Chart layouts contain configuration only, without the underlying spreadsheet records. Users can reload a layout after importing a compatible dataset. User Experience The interface uses a single readable theme with PandaDev blue and teal accents, larger text, and responsive layouts for desktop and mobile screens.

Navigation includes:

• Charts
• Data
• Data details
• Back to upload
• Resume dashboard
• Replace file
• Clear data Returning to the upload page retains the current dashboard for resuming. Clearing data resets the workspace.

The application supports English and Spanish, including translated navigation, controls, and validation messages. Uploaded column names and data values remain unchanged. Security and Privacy Security protections include:

• Local spreadsheet processing in dedicated browser workers
• Processing timeouts and cancellation
• File-size, table-dimension, and cell-length limits
• XLSX archive checks before parsing
• Validation of column headers, import settings, and chart layouts
• Formula-injection protection for CSV and Excel exports
• Text-based rendering of imported content
• Restrictive production security headers The application does not evaluate spreadsheet formulas or execute macros. Cached Excel formula results may be available for display.

Only the language preference is saved to local storage. Spreadsheet data and import settings remain in browser memory until cleared or the page is refreshed. Downloaded files remain on the user’s device.

These protections reduce risk; they do not guarantee that every spreadsheet or browser environment is safe. Supported Limits Resource Limit File size 25 MB Imported data rows 50,000 Columns 200 Raw cells 2 million Characters per cell 10,000 Worksheets per workbook 100 Charts per dashboard 12 Groups displayed per chart First 25 in source order

Merged layouts, multiple unrelated tables on one sheet, encrypted workbooks, unsupported number conventions, and Excel display-only formatting may require preparation before import. Technology and Deployment Built with:

• React for the application interface
• Vite for development and production builds
• Recharts for visualizations
• Papa Parse for CSV and TSV parsing
• SheetJS for Excel processing
• html2canvas and jsPDF for dashboard exports

Intended Use

Data Visualiztion Tool is suitable for exploring sales reports, comparing business metrics, reviewing operational spreadsheets, and preparing visual summaries from local datasets.