Step 1
Add your data
Up to 5 MB. The file is read in this browser tab and is not uploaded.
Step 2
Choose what to look for
Step 3
What Data Check found
Needs a person to fix
Where each one is
Step 4
Clean and download
Choose what to do with each item above, then check the preview. Nothing changes in your original file.
In previews, · is a space, → a tab, ↵ a line break, and [U+200B] names an invisible character. The cleaned file is saved as UTF-8.
Why clean data before a database import
Data copied out of spreadsheets, web pages, PDFs, and other systems often carries characters nobody can see. A trailing space makes "Bob " and "Bob" two different customers. A no-break space stops a lookup from matching. A byte-order mark becomes part of the first column's name, so the import cannot find the column. A line break inside a value splits one row into two.
Most of these do not cause an error. The import works, and the problem shows up later as duplicates, failed searches, and reports that do not add up. Checking the file first is quicker than cleaning the database afterwards.
How cleaning keeps your file valid
- Data Check reads a CSV the same way a database does, row by row and column by column, including values in quotes that contain commas or line breaks.
- It only searches and changes the values. The commas, semicolons, or tabs between columns and the quotes around values stay in place, so removing every comma from the values still leaves a file with the same rows and columns.
- A value is rewritten only if something in it changed. Every other row is copied exactly as it was, down to its line ending.
- Rows with broken quoting are reported and copied unchanged, because rewriting them could move values into the wrong column.
- Garbled accents, lost characters, and look-alike letters are only reported until you choose a fix, because they can change what a value means.
Private by design
Your data is read and cleaned by code running in this browser tab. It is not uploaded, stored, or sent anywhere, and this page carries no advertising or analytics code. The site counts only how many times a check was run and a cleaned file was saved, never what was in it.