Free CSV Converter: No Sign-up, Files Never Uploaded
Change the format of CSV files for free, with no sign-up and no upload. The conversion happens in this tab, so your files never leave your computer or phone.
CSV in short. Comma-separated values: one row per line, plain text with no formatting. Opens in every spreadsheet and database tool.
From CSV you can convert to XLSX, XLSB, XLS, ODS, FODS and TSV, and 12 more formats. These pairs run on code already in the page, with no extra engine to download. Document-style pairs keep text, headings, lists, tables and images, while complex layouts are simplified.
- Free
- No sign-up
- Never uploaded
- No watermark
Your files are converted on your device and never uploaded.
How to convert
- Add your CSV files by dragging them onto the converter or by using the file picker.
- Choose the format you want from the list of targets that fit your file.
- Open the options if you want to change quality or size, or keep the defaults.
- Press Convert and watch the progress shown for each file.
- Download each result, or take them all together as one ZIP when you converted several files.
Features
- Reads .csv files and can also write them.
- Free, with no watermark added to the result.
- No sign-up and no login.
- Your files are never uploaded and never leave your device.
- Batch conversion with a ZIP download for several results.
- The input is recognised by its content, not only by its file name.
- 18 target formats to choose from.
Supported formats
| Format | Read | Write | Notes |
|---|---|---|---|
| HTML.html | Yes | Yes | The markup language of web pages. |
| Plain text (TXT).txt | Yes | Yes | Unformatted text with no styles, images or layout. |
| Excel (XLSX).xlsx | Yes | Yes | The default Excel format since 2007. |
| Excel macro-enabled (XLSM).xlsm | Yes | No | XLSM can be read but not created because macros cannot be generated; convert it to XLSX. |
| Excel binary (XLSB).xlsb | Yes | Yes | Excel’s binary workbook format: opens and saves faster on very large files. |
| Excel 97-2003 (XLS).xls | Yes | Yes | The Excel format used until 2003. |
| OpenDocument Spreadsheet (ODS).ods | Yes | Yes | The spreadsheet format of LibreOffice Calc and OpenOffice. |
| Flat ODS (FODS).fods | Yes | Yes | OpenDocument spreadsheet stored as one plain XML file instead of a ZIP. |
| Apple Numbers.numbers | Yes | No | Numbers is Apple’s proprietary format, so it can be read but not created; convert it to XLSX or CSV. |
| CSV.csv | Yes | Yes | Comma-separated values: one row per line, plain text with no formatting. |
| TSV.tsv | Yes | Yes | Tab-separated values: like CSV but split on tabs. |
| dBase (DBF).dbf | Yes | Yes | The table format of dBase, also used by shapefiles and old accounting software. |
| SYLK.sylk | Yes | Yes | Symbolic Link: a text spreadsheet interchange format from Microsoft Multiplan. |
| DIF.dif | Yes | Yes | Data Interchange Format, created for VisiCalc in 1979. |
| PRN.prn | Yes | No | PRN is a printer-style text export that is read only here; convert it to CSV. |
| JSON.json | Yes | Yes | JavaScript Object Notation: the usual format for web APIs. |
| Markdown table.md | No | Yes | A table written with pipes and dashes, rendered by GitHub and most Markdown tools. |
| SQL INSERT.sql | No | Yes | A script of INSERT statements that loads the rows into a database table. |
About the formats
About CSV
Comma-separated values: one row per line, plain text with no formatting.
Opens in every spreadsheet and database tool.
It does not support transparency.
What CSV can become
CSV to XLSX runs in the page.
CSV to XLSB runs in the page.
CSV to XLS runs in the page.
CSV to ODS runs in the page.
CSV to FODS runs in the page.
CSV to TSV runs in the page.
CSV to TXT runs in the page.
CSV to DBF runs in the page.
Converting to CSV
Pages for converting to CSV start from SRT, XLSX, XLSM, XLSB, XLS, ODS, FODS and Numbers.
Privacy: how it works
- Your CSV files stay on your device. The page reads each file with the browser's file API, converts it with code running in the tab, and hands the result back as a download. No upload happens, so there is no copy of your file on our servers to protect, delete or leak.
- There is nothing to sign up for and no login. The converter does not ask for an email address, and it does not need to know who you are to do its job.
- You can check the claim yourself: open your browser developer tools, watch the Network tab while a file converts, and you will see no request that carries your file.
Tips
- Check dates, long numbers and leading zeros in the result, because text formats store everything as plain text.
- Formulas become their values when you export to a plain format.
- Only the first sheet is exported to CSV and similar formats, so split a workbook first if you need every sheet.
- Keep the original workbook as the editable master.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial, no credit card and no watermark added to your results. Ulkaa Tool does the conversion with your own device, so there is no server bill to pass on to you.
Are my files uploaded?
No. Your CSV files are read and converted inside your browser and are never sent to Ulkaa or to anyone else. The result is created on your device and you save it from there.
Do I need an account?
No. There is no sign-up and no login. Open the page, add your files and convert. An Ulkaa account is not needed for anything on this tool.
Is there a file size limit?
No limit is set by us. The real limit is your device: the conversion uses your own memory and processor, so very large files can be slow, and a very big batch may need to be split into smaller runs.
What can I convert CSV files to?
You can convert CSV to XLSX, XLSB, XLS, ODS, FODS, TSV, TXT, DBF, SYLK, DIF, HTML, JSON, MD Table, SQL, PDF, JSONL, YAML and XML. Pick one on the converter and it applies to every file you add.
Can I convert other files to CSV?
Yes. SRT, XLSX, XLSM, XLSB, XLS, ODS, FODS, Numbers, TSV and DBF can be converted to CSV.
Can I convert many CSV files at once?
Yes. Add as many files as your device can handle. Each one is converted on its own and you can download them one by one or as a single ZIP.