CSV & Excel Spreadsheet Utilities
Browser-native tools to convert, clean, merge, compare, and inspect CSV and Microsoft Excel files. Everything runs 100% locally in your browser.
Excel Compare & Cell Diff
Compare two Excel workbooks side by side with sheet selection, added/removed row metrics, and individual cell value diffing.
Open tool →Excel Sheet & Workbook Merger
Combine multiple Excel files or sheets together by appending rows, matching column headers, or merging by a key column.
Open tool →Excel Data Cleaner
Strip empty rows/columns, remove duplicates, normalize headers, convert dates, and clean up messy workbooks.
Open tool →CSV to Excel Converter
Convert CSV and TSV files into styled, native Microsoft Excel (.xlsx) workbooks instantly in your browser.
Open tool →Excel to CSV Converter
Extract any sheet from Excel (.xlsx/.xls) into clean, standard CSV or TSV with customizable delimiters.
Open tool →CSV Cleaner & Formatter
Remove duplicate rows, strip unwanted whitespace, eliminate empty rows/columns, and repair broken quotes.
Open tool →CSV Diff Checker
Compare two CSV files side by side with cell-level change highlighting, added/removed row tracking, and export.
Open tool →Spreadsheet Table Viewer
Interactive in-browser spreadsheet table reader with column sorting, live search filtering, and column summary stats.
Open tool →CSV Merge & Combiner
Combine multiple CSV files by appending rows vertically or merging side-by-side using a common primary key.
Open tool →CSV Column Filter & Reorder
Select, rename, reorder, or drop specific columns and filter rows using custom search conditions.
Open tool →CSV to JSON Converter
Transform tabular CSV rows into structured JSON arrays of objects or 2D arrays with automatic type detection.
Open tool →JSON to CSV Converter
Flatten nested JSON objects, API responses, or arrays into downloadable CSV or Excel tables.
Open tool →CSV to Markdown & SQL
Generate GitHub-flavored Markdown tables, clean HTML tables, and SQL CREATE TABLE / INSERT INTO statements from CSV.
Open tool →How in-browser spreadsheet processing works
Traditional spreadsheet utilities upload your files to remote servers, convert them in a cloud queue, and return a download link. This creates severe security risks when handling proprietary customer databases, financial records, medical registries, or internal sales reports. DailyUtils processes all spreadsheet calculations and transformations client-side using JavaScript typed arrays, WebAssembly, and native OpenXML packaging.
Whether you are standardizing messy CSV export files from legacy CRM platforms, converting nested JSON API responses into pivot-ready Microsoft Excel workbooks, or identifying changes between monthly price lists with side-by-side cell diffing, every byte remains strictly on your local machine.
Spreadsheet tools comparison guide
Frequently asked questions
Are my CSV or Excel spreadsheets uploaded to a server?
No. Every spreadsheet transformation, Excel workbook generation, and data cleaning operation runs entirely in your web browser with JavaScript. Your tabular data never leaves your computer, ensuring complete confidentiality for financial data, customer lists, and sensitive databases.
Can I compare two Excel workbooks cell-by-cell?
Yes. With the Excel Compare tool, you can upload two .xlsx files, select worksheets, and inspect detailed metrics: added rows, removed rows, changed cells with previous vs new values, and unchanged records.
How does the Excel Sheet Merger combine multiple workbooks?
You can upload multiple Excel workbooks (e.g., monthly sales reports), pick which worksheets to merge, and select between appending rows vertically, matching column headers, or joining records based on a shared key column.
Can I convert large CSV files without freezing my browser?
Yes. The underlying parser uses chunked string processing and optimized typed arrays to handle files with tens of thousands of rows efficiently. For files exceeding 100 MB, closing unnecessary background browser tabs ensures maximum available memory.
Does the CSV to Excel converter create real .xlsx files?
Yes. It generates native, uncorrupted OpenXML (.xlsx) workbooks compatible with Microsoft Excel, Google Sheets, Apple Numbers, and LibreOffice Calc, with proper cell types (numbers, dates, text) and styled header rows.
How does the Excel Cleaner handle dirty spreadsheet data?
The Excel Cleaner provides one-click options to strip empty rows and columns, remove duplicate records, trim whitespace, normalize column names, and standardize date formats before generating a clean workbook.