CSV is how data moves between systems, and it's almost always a little broken on arrival: duplicated rows, empty lines, invisible spaces, and disagreements about the separator character. Import that straight into Excel and you get misaligned columns and double-counted totals. Here's what goes wrong and how to fix it before it reaches your spreadsheet.
The five common problems
- Duplicate rows — exports often repeat records, quietly inflating counts and sums.
- Empty rows — blank lines where records were skipped break Excel's "select all" and throw off row counts.
- Stray whitespace — leading or trailing spaces inside cells are invisible but cause failed lookups and mismatched joins ("Delhi" ≠ "Delhi ").
- Empty columns — over-wide exports leave columns that are blank top to bottom.
- Wrong delimiter — the classic reason a CSV "won't open properly", especially with European files that use semicolons because the comma is their decimal separator.
Fixing them in one pass
The CSV cleaner handles all five together. Drop or paste your file and it will remove duplicate and empty rows, trim whitespace from every cell, optionally delete blank columns, and detect the delimiter automatically — with the option to override it. Crucially, you can also convert the delimiter on the way out, so a semicolon file becomes a standard comma file that opens correctly in an English-language Excel.
- Load the file (drop the CSV or paste the text).
- Tick the cleanups you want — the sensible defaults suit most files, and "first row is a header" protects your column names.
- Set the output delimiter if Excel is mangling your columns — comma is safest for English Excel.
- Download the clean CSV and import it.
Importing into Excel the right way
Even a clean CSV can misbehave if you just double-click it — Excel guesses the delimiter and the encoding, and sometimes guesses wrong (turning long numbers into scientific notation, or dropping leading zeros from IDs and postcodes). For important data, use Excel's Data → From Text/CSV instead, which lets you confirm the delimiter and set columns to text where needed. Cleaning the file first means that import step has far less to trip over.
Where the data comes from
A frequent pattern is extracting a table from a PDF with PDF to Excel, then cleaning the CSV here before it goes anywhere else — the extraction gets the numbers out, the cleaner makes them tidy. And because everything runs in your browser, even a customer list or a financial export never leaves your machine.