FAQ
Frequently asked questions about using the service.
Data & security
- Are my files sent to your server?
- No. CSV files are processed only in your browser and are not sent to our servers. We take data privacy seriously.
- What encodings are supported?
- UTF-8 (with or without BOM), Shift_JIS, and others are detected automatically. You can see the result on screen.
- Do you store my CSV contents?
- No. The tools work in your browser and do not store or accumulate your CSV contents on our servers.
- Do you use cookies or ads?
- We may use cookies for service operation and third-party advertising (e.g. Google AdSense). Details and options are explained in Privacy.
Usage limits
- Can I use it without logging in?
- Yes, completely free and no login required. You can use all the core tools directly in your browser.
- How many rows can I process?
- Since all processing runs in your browser, it depends on your device's available memory. Very large files may be slow; try splitting first with CSV Splitter.
- Why do large files feel slow?
- Processing happens on your device, so performance depends on your browser and available memory. For huge files, try splitting first with CSV Splitter.
Features
- How does «Added / Deleted / Changed» work in compare?
- Rows are compared. Rows only in one file are shown as added or deleted; rows in both with different content are shown as changed. You can show or hide columns.
- Why do compare results look wrong sometimes?
- Row matching depends on the key column. Duplicate keys, blank keys, or hidden characters can break alignment. Clean the key column with Single-file check first.
- Why does Excel show garbled text or wrong columns?
- It’s usually an encoding/BOM issue. Use Encoding recovery to export UTF-8 (BOM), then re-check in Format & basic check.
- What delimiter formats are supported?
- Common delimiters like comma, tab, and semicolon are supported. If auto-detect is wrong, you can override the delimiter in Format & basic check.
- How do I quickly diagnose import failures?
- Start with Format & basic check (encoding/delimiter/columns/BOM), then run Single-file check (duplicates/invisible chars/trim). See CSV errors guide for the checklist.