100% browser-based

CSV Toolkit

Open a CSV or TSV, inspect it, clean it up, filter rows or merge another file without uploading it.

How to use this →

LOCAL PROCESSINGNO UPLOADFREE

01 / INPUT

Open your file

Choose the CSV or TSV you want to work with.

Drop your CSV or TSV hereor choose a file below

Choose file

Local processing · no upload

Primary CSV or TSV file

No file yet? Use a small sample with duplicate and empty rows.

02 / CONFIGURE

Choose what to change

Only selected changes are applied

Rows-

Columns-

File size-

WHAT TO EXPECTA new CSV or TSV with only the changes you choose.Your original file stays untouched.

Select a file to inspect columns.

Remove duplicates Remove empty rows Remove empty columns

Rename headers
Change one column name.

Filter rows
Keep only matching rows.

Separator

03 / CLEAN & EXPORT

Review & download

Your original file stays untouched

Merge two files
Add columns from a second file by matching a shared ID.

COMPARE

Compare two CSV files

See which rows exist only in one export and which values changed for the same ID.

Compare files →

CONTINUE

Keep working in Opselith.

Open another tool or switch to the PowerShell Builder.

← All tools PowerShell Builder

About CSV handling

CSV safety note

Use Download exact result when another admin tool must receive the original values unchanged. Use Download spreadsheet-safe result for Excel or another spreadsheet; formula-like cells are exported as text.

Clean CSV and TSV files locally

See what is in the file, remove duplicates or empty rows, rename columns, filter records and merge another CSV when you need to.

Made for admin exports

Use it with exports from Microsoft 365, Active Directory and other admin systems. Review sensitive files before you share them or open them in Excel.

Review an AD or Entra user export →
Review an AD or Entra group membership export →