About FileGlance

Powerful tool for viewing, filtering, and transforming tabular data files using JavaScript.

Why FileGlance?

1. Needing different tools for different formats.
2. Lack of tools optimized for quickly understanding data.
3. Messy files that require cleaning before use.

I built FileGlance as a side project and a fun way to learn React and Tailwind.

Maybe it will help others, too.

It aims to be both:

• Simple: Just drag and drop a file; it automatically detects encoding, delimiter, headers, and more.
• Powerful: Run custom JavaScript to filter and transform data at scale.

Features

• Drag-and-drop support for all common file types (CSV, XLSX, JSON, etc.)
• Automatic detection of file encoding, delimiters, and data location
• Optimized display (hides empty columns by default)
• Simple filtering with value facets for exact matches
• Full-text search across data
• Basic sorting functionality
• Advanced row filtering using custom JavaScript
• Advanced value transformation using custom JavaScript
• One-click export to CSV, XLSX, or JSON
• Handles large files with virtualized list rendering
• Visual representation of value counts (histograms for numeric data)
• Progressive Web App (PWA) support
• Privacy-focused: Your data never leaves your device

Use Cases

Data Viewing & Exploration

View raw data and column types. Get visualizations for categorical and continuous data (histograms). For numeric values, see statistics like average, median, min, and max. Use it as:

• Online CSV / TSV / Excel viewer
• See column stats like average, median, min, and max for numeric columns (e.g., "Find the average order value in a sales CSV")
• Data type inspector (e.g., "Quickly validate which columns are text, numbers, or dates")
• File converter (e.g., "Convert an Excel file to CSV or JSON in one click")

Data Filtering & Cleaning

Apply quick filters with one click or use complex filter functions with custom JavaScript. For example:

• Remove empty rows or columns
• Trim whitespace from values
• Deduplicate based on specific columns
• Find unique values
• Replace missing values with defaults
• Detect and handle outliers

Data Transformation

Transform data using custom JavaScript functions. For example:

• Parse numbers from text
• Normalize text case (e.g., all lowercase)
• Split the domain from an email
• Format Unix timestamps to readable dates
• Merge similar categories (e.g., "NY" and "New York")
• Export to CSV, JSON, Markdown etc.

Tech Stack & Code

FileGlance is built with TypeScript, Next.js/React, Tailwind CSS, and Recharts. It is open source under the AGPL license. Interested developers can find the full source code on GitHub: https://github.com/dell-mic/file-glance