View Big CSV Files in Your Browser

Large CSV Viewer opens big CSV files of any size by uploading them in 15 MB chunks to a DuckDB server engine. The browser only loads the rows currently on screen, so it never freezes or crashes regardless of how big the file is. Files over 10 GB and 100 million rows have been tested successfully. Free, no account required.

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Open and view big CSV files online free. No crashes, no row limits. View, filter, sort, and search huge CSV files of any size instantly.

Big CSV files break most tools — Excel freezes, Google Sheets refuses to import, and desktop apps run out of memory. Large CSV Viewer is built for big CSV files: a streaming architecture backed by DuckDB processes your file server-side while your browser only renders the rows you're looking at.

Key features

  • Opens big CSV files of any size — no crashes
  • Tested on files over 10 GB with 100M+ rows
  • Browser only loads the rows you're viewing — stays fast
  • Sort, filter, and search the full big file server-side

How it works

  1. Upload your big CSV file. Your file uploads in 15 MB chunks, so even huge CSVs start loading immediately. You can begin previewing data before the upload completes.
  2. Query with DuckDB. Once uploaded, DuckDB indexes the entire file. Every filter, sort, and search runs server-side at SQL speed against the full big dataset.
  3. Navigate and export. Scroll through your big CSV using infinite scroll or pagination. Export filtered results as CSV, JSON, or Excel with no row limits.

Ready to try it?

Free, instant — no account or install needed.

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Frequently asked questions

What makes this a viewer for big CSV files?

Unlike Excel or Google Sheets, Large CSV Viewer uses a streaming architecture. Big files are uploaded in chunks and queried by DuckDB on the server — your browser only fetches the rows you're viewing, so it never freezes.

How big a CSV file can I open?

There is no hard limit. Files over 10 GB and 100 million rows have been tested successfully.

Why do big CSV files crash Excel?

Excel has a hard limit of 1,048,576 rows. Any CSV larger than that either crashes or gets silently truncated. Large CSV Viewer has no such limit.

Can I search a big CSV file?

Yes. Search and filter queries run server-side using DuckDB on the full dataset, regardless of file size — results return in under a second for most queries.

Is it free to open big CSV files?

Yes, completely free. No account, no size paywall, no limitations.