Do you upload my files to your servers?

No. All file processing happens locally in your browser using the File API. Your CSV, Excel, and text files never leave your machine — they are never uploaded or stored anywhere.

What file formats are supported?

We support CSV (.csv) for the CSV Viewer, Diff, and related tools; Excel (.xlsx, .xls) for the Excel Reader; and plain text for the Text Diff and Word Counter. The Markdown Preview accepts .md files or pasted text.

Is there a file size limit?

Since processing happens in your browser, limits depend on your device's available memory rather than server restrictions. Most tools handle files up to 50-100 MB smoothly, with larger files depending on available RAM.

Can I compare files from different sources?

Yes. The CSV Diff and Text Diff tools accept input by file upload or by pasting text directly. You can compare files from different locations without downloading them to the same folder.

Data Tools — Free Online Data Analysis Tools

Data Tools

Analyze, compare, and explore data files — fast, in your browser.

8 tools available

All Data Tools

CSV Viewer

CSV

View CSV files in an interactive sortable and filterable table with column statistics.

CSV to JSON

Convert

Convert CSV files to JSON format — choose between array of objects or array of arrays.

JSON to CSV

Convert

Paste or upload JSON and convert it to CSV with configurable delimiter options.

Excel Reader

Excel

Open XLS and XLSX files in your browser — view sheets, sort columns, and search data.

Excel to CSV

Convert

Convert Excel spreadsheets to CSV format — select sheets and download instantly.

CSV Diff

Compare

Compare two CSV files side by side with color-coded added, removed, and modified rows.

PDF Tools

PDF

Merge, split, and compress PDF files directly in your browser. No uploads to external servers.

CSV to SQL

Data Tools

Convert CSV data into SQL INSERT statements for any database.

Work With Data Without Installing Anything

Data tools fill the gap between raw files and insights. Whether you need to quickly glance at a CSV without opening Excel, compare two versions of a configuration file, count words in an article, or see how a Markdown document will render — CheckTown's data tools let you do all of this in seconds, directly in your browser.

What Data Tools Are Available?

Our data tool collection includes file viewers (CSV Viewer with sortable columns, Excel Reader for .xlsx files), comparison tools (CSV Diff for comparing two CSV files side-by-side, Text Diff for line-by-line text comparison), and text analysis tools (Word Counter with character, sentence, and paragraph counts).

We also include content tools for developers and writers — the Markdown Preview renders your .md files with full syntax support including tables and code blocks, the Emoji Picker lets you find and copy emoji characters with search, and the Data Format Validator checks JSON, YAML, and XML files for syntax errors.

Data Tools

All Data Tools

Work With Data Without Installing Anything

What Data Tools Are Available?

Frequently Asked Questions

Related Guides

CSV Viewer: Open and Inspect CSV Files Without Excel

CSV to JSON Converter: Transform Tabular Data in One Click

JSON to CSV: Export Structured Data as a Spreadsheet

Excel Reader: View XLSX Files Directly in Your Browser

Excel to CSV: Convert Spreadsheets to Universal Format

CSV Diff: Compare Two CSV Files and Find Every Difference

PDF Tools: How to Merge, Split & Compress PDFs in Your Browser

CSV to SQL: Convert Spreadsheet Data to Database INSERT Statements