CSV test-file generator

Generate a synthetic, multilingual CSV file of any size up to 20 GB directly on your machine and stream it to disk. Use it to benchmark the Fast CSV Viewer, your own parser, or any CSV tooling. Nothing is uploaded — the bytes go straight to a file you pick.

Generate

Tip: 1 KB – 20 GB. Generation runs in a background worker and is typically disk-bound — expect a few hundred MB/s on a fast SSD.

Output format

An RFC 4180 CSV with a header row, then one record per line. The default schema:

id,uuid,first_name,last_name,email,country,city,signup_date,age,balance,active,bio,tags

Name, city, and free-text cells are drawn from curated word lists across the selected scripts (incl. Arabic, Hebrew, Japanese, Ukrainian), so the file exercises the full UTF-8 range. A configurable share of bio/tags cells embed the delimiter, doubled quotes, or a literal newline — quoted per RFC 4180 — to stress a parser's quoting across block boundaries.

How it works

The page uses the File System Access API (showSaveFilePicker) to open a writable stream, then hands the handle to a module Web Worker that streams ~1 MB chunks until the target size is reached. The next chunk is generated while the previous one writes, and there is no in-memory buffer of the whole file — the same path works for 1 KB and 20 GB.