All essentials

Drop a CSV and I'll work out the delimiter and lay it out — nothing is uploaded.

Free tool

CSV Viewer

Open a CSV or TSV in your browser as a proper table — the delimiter worked out for you, quoted fields handled, with search and sorting. Nothing is uploaded.

Good to know

  • Comma, tab, semicolon and pipe are all detected — a European CSV opens as readily as an American one.
  • Quoted fields with commas or line breaks inside them are read properly, which is where a spreadsheet import usually goes wrong.
  • Rows with too few or too many fields are padded or trimmed so the columns still line up, and you are told it happened.

Your files stay on your machine

This tool runs entirely inside your browser tab. Nothing is uploaded, stored, or sent to a server — close the tab and every trace is gone.

These are the free ones — see the full suite

How big a file can it take?

There is no upload, so there is no upload limit — but the work happens in this tab, which means your browser’s memory is the budget. Nothing here will refuse a file for being large; a big enough one simply gets slow and, eventually, reloads the tab. The figures below are rules of thumb on a desktop browser, not enforced caps. On a phone or tablet, expect a good deal less.

  • The whole file is read as text and then again as cells — comfortable to around 50,000 rows, which is where the reader stops and says so.
  • A file of few, wide columns is much lighter than the same size split across a hundred narrow ones.

Password-protected PDFs are declined whatever their size — unlock the file first. If a run does die on a long document, splitting it into volumes and working through them one at a time is the reliable way round it.

Built on open source

The Essentials tools do their work in your browser using these open-source libraries, used under the licenses below. Each remains the copyright of its authors.

  • pdf-libMIT · creates and edits the PDFs you download
  • pdf.jsApache-2.0 · reads your PDF and renders the page previews
  • SheetJS (xlsx)Apache-2.0 · reads Excel workbooks — .xlsx, .xls, .xlsb and .ods
  • hyparquetMIT · reads Apache Parquet files
  • hyparquet-compressorsMIT · the Parquet codecs beyond Snappy — Gzip, Zstd, Brotli, LZ4
  • JSZipMIT · bundles multi-file results into one ZIP
  • LucideISC · the icons throughout these tools
  • ReactMIT · the interface itself
  • Next.jsMIT · builds and serves these pages

pdf.js ships fallback fonts contributed by Foxit Software, redistributed here as part of pdf.js. JSZip is dual-licensed; it is used here under the MIT license.