Tables and spreadsheets
Clean and convert spreadsheets, on your device.
Open a CSV, TSV, JSON or Excel file. Nelvumo Table shows how it was read, cleans a copy and saves it as CSV, TSV, JSON or Excel, in your browser.
Free to use · No account · No file uploads
Your files stay on your device. Spreadsheets often hold personal and financial details. The separate workspace reads them in your browser and makes the copies there. This guide site never receives your files.
Things you can do
From a messy export to the file you need.
Every step says what it changes, and every step can be undone.
Clean a CSV
Trim spaces, drop empty rows, remove repeated rows and choose the columns to keep.
See the guide 02 / FIXFix separators and accents
See the encoding and separator detected, read the file again another way, save UTF-8.
See the guide 03 / CONVERTConvert to Excel or JSON
Workbooks that keep leading zeros and long ids as text, or JSON keyed by heading.
See the guideHonest reading
You see how a file was read before anything changes.
Encoding and separator detection is a guess, so Files always shows what was detected and the first lines as read, and you can choose again. Values are kept exactly: 00123 stays 00123. Every copy is read back and checked before it is offered.
See the full workflowReady when you are
Make the file you were asked for.
Your files stay unchanged. The separate workspace keeps them on your device.
Open the workspace