Or paste CSV text
Compress CSV files and clean them up
CSV files get big fast. Exports from spreadsheets, CRMs, and databases are often padded with quotes around every value, spaces around commas, blank rows, and empty columns. They also compress extremely well, because data repeats. This tool does both jobs: it tidies the file without changing a single value, then packs it into a ZIP or gzip file that's typically 80 to 90 percent smaller than the original.
Everything runs in your browser, so customer lists, financial exports, and other private data never leave your computer.
How to use it
- Choose a CSV or TSV file, drop one on the box, or paste CSV text.
- Review the cleanup options. The defaults are safe for almost every file.
- Check the results: sizes, what changed, and a preview of the cleaned rows.
- Download the cleaned CSV, a ZIP to share, or a gzip file for data tools.
Two ways to make a CSV smaller
1. Clean it (still a normal CSV)
Cleanup removes characters that don't carry any data. It stays a plain CSV that opens anywhere, just lighter:
"id","name","city" → id,name,city
"1","Ada Lovelace" , "London" → 1,Ada Lovelace,London
"2","Cy, Jr.","New York" → 2,"Cy, Jr.",New YorkNotice that "Cy, Jr." keeps its quotes. It contains a comma, so it needs them. The tool only removes quotes that aren't needed. Values containing commas, quote marks, or line breaks are always quoted correctly.
2. Compress it (ZIP or gzip)
Real compression is where the big savings are. A 90 MB export with 1.2 million rows compressed to under 16 MB in testing, 83 percent smaller. Choose ZIP to email or share a file, since everyone can open it. Choose gzip for data work: pandas (pd.read_csv("file.csv.gz")), R, PostgreSQL, BigQuery, and most command-line tools read .csv.gz directly without unpacking it first.
What each option does
| Option | Effect | Changes data? |
|---|---|---|
| Remove unneeded quotes | Drops quotes around values that don't contain the delimiter, quotes, or line breaks | No |
| Trim spaces around values | Removes stray spaces next to delimiters, like a , b | Only removes outer spaces. Spaces inside quotes are kept. |
| Remove blank rows | Deletes rows where every value is empty | No real data |
| Remove duplicate rows | Keeps the first copy of each identical row, including repeated header rows from merged files | Yes, removes rows. Off by default. |
| Remove empty columns | Deletes columns that are blank in every row, including the header | No real data. Off by default. |
| Line endings | LF saves one byte per row compared with CRLF | No |
Verified, value by value
After cleaning, the tool reads its own output back as CSV and compares a fingerprint of every value with what it intended to write. The green Verified badge means every row and value came through exactly as expected. The parser follows the CSV standard (RFC 4180), including quoted values that contain commas, doubled quote marks, and line breaks, and it was tested against Python's built-in csv module on hundreds of tricky files.
Frequently asked questions
Is my CSV uploaded anywhere?
No. The file is read, cleaned, and compressed inside your browser, and nothing is sent to FlipperFile or anyone else.
Will Excel still open the cleaned file?
Yes. The result is a standard CSV. Keep the UTF-8 marker option on so Excel shows accented characters like é and ñ correctly, and choose CRLF line endings if a very old Windows program will read the file.
Why did my file only get a little smaller after cleaning?
If the original had no extra quotes, spaces, or blank rows, there's not much to remove, and that's a sign of a well-made file. The ZIP and gzip downloads will still shrink it dramatically.
Does it change numbers or dates?
No. Values are kept exactly as written, including leading zeros like 00123, date formats, and decimal places. It only changes the characters around values.
My file uses semicolons. Will that work?
Yes. The delimiter is detected automatically, whether it's commas, semicolons (common in Europe), tabs, or pipes. You can also save the result with a different delimiter.
What if my file isn't UTF-8?
If the file isn't valid UTF-8, the tool reads it as Windows-1252, the most common encoding for older Excel exports, and saves the result as UTF-8. It tells you when it does this.
How large a file can it handle?
Files up to 300 MB work in most desktop browsers. A 90 MB, 1.2-million-row file took a few seconds in testing. Processing happens in a background thread, so the page stays responsive.