Free online data and spreadsheet tools
Open CSV, Excel, Access, SPSS, Parquet and science data files, run SQL and convert between formats, in your browser.
A data export is often the most sensitive file an organisation has - customers, salaries, orders, API keys in a config file. It is also the kind of file people most casually paste into the first converter a search turns up. Every tool on this page but one parses and converts in your own browser, so none of that travels.
For tabular data, the CSV Toolkit opens a file in a sortable table, flags the rows that did not parse cleanly, charts a column and exports tidied CSV or JSON, and opens CSV and log files of several gigabytes - far past Excel's 1,048,576 rows - reading them a piece at a time so you can scroll to any row, filter every row and save the ones you want. When a question needs more than sorting, the SQL Playground runs genuine SQLite - compiled to WebAssembly, not simulated - against a database file or a CSV, so joins, aggregates and window functions all work. The Excel Viewer opens .xlsx, .xls and .ods spreadsheets without Excel, shows the formula behind any cell, and opens Stata .dta datasets too, and the Access Database Viewer opens .mdb and .accdb files without Microsoft Access - on a Mac or a Chromebook too - and saves every table as Excel, CSV or a SQLite database.
For research data, the Parquet Viewer opens the columnar files Spark, pandas and the data warehouses write, the SPSS & SAS Viewer opens .sav, .sas7bdat, .xpt and .dta files with value labels, statistics and frequencies, the RDS & RData Viewer opens R's files without R, the MAT, HDF5 & NetCDF Viewer opens MATLAB and scientific data files without MATLAB or Python, and the Prism File Viewer reads the data tables out of a GraphPad Prism project. For structured text, the JSON Formatter formats, minifies, validates and sorts keys, and the Format Converter moves documents between JSON, YAML and XML. The Archive Toolkit builds ZIP files, with a password if you want one, and opens ZIP, RAR, 7z, TAR and ISO archives locally, along with MSI installers, Mac DMG images and VHD, VHDX and VMDK virtual disks, and the Unit and Base Converter handles measurements and number bases.
One exception worth naming: ZIP to Text is the single tool on this page that does upload. It sends an archive to this site's own API to be joined into one text file, held only while it is processed - briefly in a temporary file for larger uploads - and deleted straight after, with a 25 MB limit. It says so on its own page, and it is the only one here that needs to.
- CSV ToolkitOpen a CSV or log file of any size in your browser, even several GB: scroll to any row, filter, summarise columns, convert to JSON. Nothing is uploaded.
- Excel ViewerOpen .xlsx, .xls, .xlsm or .ods files online without Excel; .xlsx and .xlsm show colours, merged cells, frozen panes, charts and pictures. Free, no upload.
- SQL PlaygroundRun real SQLite queries against a .sqlite file or a CSV, entirely in your browser. Nothing is uploaded, so you can query private data safely.
- Access Database ViewerOpen Access .mdb and .accdb files online without Access, on Windows, Mac or Chromebook: browse tables, run SQL, export to Excel, CSV or SQLite. No upload.
- JSON FormatterFormat, minify, validate and sort JSON, with the position of the first syntax error reported. Runs entirely in your browser — nothing is uploaded.
- Format ConverterConvert JSON to YAML, YAML to JSON, or either to XML and back. Runs entirely in your browser, so config files with secrets never leave your machine.
- Parquet ViewerOpen a .parquet file in your browser: browse, sort and filter rows, read the schema and column stats, and save as CSV or JSON Lines. Nothing is uploaded.
- RDS & RData ViewerOpen R's .rds and .RData files without R: see each data frame as a table, look inside lists, and save the data as CSV, Excel or JSON. Nothing is uploaded.
- SPSS & SAS ViewerOpen SPSS .sav, SAS .sas7bdat and .xpt, and Stata .dta files without the software: value labels, statistics, frequencies, Excel export. Nothing uploaded.
- MAT, HDF5 & NetCDF ViewerOpen MATLAB .mat, HDF5 and NetCDF files without MATLAB or Python: browse variables, see slices as tables, charts and heat maps, save CSV. No upload.
- Prism File ViewerOpen a GraphPad Prism .pzfx project without Prism: see every data table as Prism lays it out and save the tables as CSV for Excel or R. No upload.
- CPAP Data ViewerOpen the SD card from a ResMed CPAP machine or any EDF sleep recording: nights, hours of use, AHI as recorded, flow, pressure, leak and events. No upload.
- Archive ToolkitOpen RAR, 7z, ZIP, TAR and ISO files online and save the files inside, or make a password-protected ZIP. All in your browser: nothing is uploaded.
- Virtual Disk ConverterConvert VMDK, VHD, VHDX, VDI, QCOW2 and raw IMG virtual disks into each other for Hyper-V, VMware, VirtualBox, Proxmox or Azure. Free, nothing uploaded.
- Unit & Base ConverterConvert length, mass, temperature, area, volume, speed, time and data units, and between binary, octal, decimal and hex. Instant, in your browser.
- ZIP to TextUpload a ZIP and get back one text file joining every text file in the archive, in order. Free, no sign-up, and nothing is kept after the download.