CSV Converter
FileFlip converts CSV files into 5 other formats entirely inside your browser, using the text engine compiled to WebAssembly. The CSV file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. There is no file-size limit and no account to create.
How do I convert a CSV file?#
- Drop your CSV file onto the converter at the top of this page, or click it to pick one from your computer.
- Choose the format you want out of it. FileFlip downloads the engine that conversion needs, once, and your browser caches it.
- Conversion starts the moment you pick the format, and the result is yours to download. The work happens in this tab, so nothing is uploaded and nothing is queued.
Is it safe to convert CSV files online?#
Yes, because nothing is uploaded. FileFlip converts CSV files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What happens to a CSV file#
FileFlip converts CSV into 5 formats with the text engine, all of it inside the browser tab. Each conversion below names the engine it uses, what it downloads, and exactly what that conversion keeps or drops.
| Category | Data Files |
|---|---|
| File extension | .csv |
| FileFlip support | Read and written |
| Conversions available | 5 |
| Engines | the text engine |
| Downloaded to your browser | Nothing. Your browser already has everything these conversions need |
What is a CSV file?#
A CSV file holds a table as one line of text per row, with values on each line separated by commas, and no single formal specification that every producer of the format agrees on.
Use CSV to move a flat table between spreadsheets, databases and scripts, where every consuming tool already knows how to read it.
Convert CSV to JSON when the data needs to travel into an API or a program expecting typed, nested structures instead of a flat table of strings.
The CSV file format reference covers the specification, the programs that open one, and what each conversion keeps or drops.
CSV questions people ask#
Is there an official CSV specification?
Not one that every CSV file actually follows. RFC 4180, published in 2005, documents common conventions, like wrapping a value in double quotes when it contains a comma, but it describes existing practice rather than binding every tool that writes CSV. Delimiter, quoting and line-ending choices still vary enough between spreadsheet programs and databases that CSV is really a family of similar formats, not one format.
Why does opening a CSV in Excel mangle special characters?
CSV has no way to declare its character encoding inside the file itself, and Excel's CSV import on Windows has historically guessed the system's default encoding instead of UTF-8. A file saved as UTF-8 with accented characters or emoji then displays as garbled text until it's reopened with the encoding specified explicitly.
Why did Excel strip the leading zeros from my ZIP codes?
CSV has no type system, so every value is just text until the program reading it decides otherwise. Excel guesses that a column of digits is a number, and a number can't have a leading zero, so 01234 becomes 1234 the moment the file is opened, unless the column is reformatted as text first.
What happens to a nested JSON object when converting it to CSV?
CSV can only represent a flat table, so a JSON object nested inside a field has to be flattened, typically into several columns named with a dot, like address.city and address.zip, or serialized to a JSON string inside a single cell. Which approach a converter uses isn't standardized, so the same nested JSON can produce different CSV layouts depending on the tool.