Corrupt a CSV File Online
Corrupt a .csv file online for free. Breaks delimiters, quoting and encoding so spreadsheet apps and data pipelines reject the file.
- No upload
- No size limit
- No sign-up
Corrupt your CSV file
Tuned for .csv, .tsv, and works with every other format too.
Why CSV files are hard to corrupt properly
CSV has no schema, no header requirement and no terminator, so almost any byte sequence is arguably a valid CSV file. The formats that matter are the ones the consumer expects (consistent column counts, balanced quotes and decodable text) and those are what get destroyed here.
What this tool destroys
- Delimiter structure. Commas and line breaks are overwritten, so rows no longer split into a consistent number of columns.
- Quote balance. Double quotes are broken up, leaving quoted fields permanently unterminated and swallowing subsequent rows.
- Encoding validity. Invalid UTF-8 sequences are injected, so strict readers fail before parsing.
- The header row. The opening bytes are destroyed, so column names are lost and type inference fails.
What you will see afterwards
| Application | Behaviour |
|---|---|
| Microsoft Excel | Imports as a single garbled column, or warns that the file cannot be read. |
pandas read_csv | Raises ParserError: Error tokenizing data or a Unicode error. |
| Google Sheets | Import produces unreadable rows or fails outright. |
| Database bulk loaders | Abort the load and report a malformed record. |
Common reasons people do this
- Testing that a bulk import rejects a bad file instead of loading partial rows.
- Verifying a data pipeline reports the failing file and row rather than dropping records.
- Checking that a CSV upload form validates before writing to a database.
- Producing malformed fixtures for a parser test suite.
How to corrupt a CSV file
- Drop your .csv file onto the box above, or click to browse.
- Leave the level on Standard unless you want partial damage (Light) or need to defeat recovery software (Heavy).
- Press Corrupt file. Processing happens on your device, so it finishes almost immediately.
- Download the result. It keeps the original filename and byte length by default.
CSV FAQ
Will Excel still open it?
Excel will usually open something, because it treats any text file as importable. What it shows is a single column of mojibake rather than your data.
Is a partially corrupted CSV worse than a fully broken one?
For testing, often yes, a file that loads 400 of 500 rows before failing is the case that catches silent data loss. Use Light level for that.
Does it work on TSV and pipe-delimited files?
Yes. Any delimiter-separated text file uses the same profile.
Will the row count stay the same?
No. Line breaks are among the bytes overwritten, so the file no longer has a predictable row structure.