View Gigabyte-Scale CSV Files in Your Browser
Large CSV Viewer handles gigabyte CSV files by uploading them in 15 MB chunks to a DuckDB server engine. The browser only fetches 50–150 rows at a time, so it never slows down or crashes regardless of total file size. Files up to 10 GB and 100 million rows have been tested successfully.
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Most CSV tools choke on files larger than a few hundred megabytes. Large CSV Viewer uses a streaming architecture backed by DuckDB to process multi-gigabyte files efficiently — you see your data in seconds, not minutes.
Key features
- Tested on CSV files up to 10 GB+
- Server-side DuckDB engine — your browser only renders what you see
- Infinite scroll and paginated view modes
- Sort any column on the full dataset, not just the visible page
How it works
- Start the upload. Your file is sent to our server in 15 MB chunks. The upload starts immediately — you don't need to wait for the full file before exploring.
- Query with DuckDB. Once uploaded, DuckDB indexes your data. Every filter, sort, and search runs as a SQL query against the full gigabyte-scale dataset.
- View only what you need. Your browser fetches 50–150 rows at a time, so the tab never becomes sluggish regardless of total file size.
Frequently asked questions
How does it handle such large files?
Files are uploaded in 15 MB chunks to the server, where DuckDB indexes them. The browser only fetches the rows you're currently viewing — typically 50–150 rows at a time.
How long does a 1 GB CSV take to upload?
On a typical broadband connection, a 1 GB file takes roughly 1–2 minutes to upload. Once uploaded, all queries are near-instant.
Can I sort a gigabyte CSV file?
Yes. Sorting is executed server-side by DuckDB on the full dataset, not just the visible rows. Results appear in seconds.
What is DuckDB and why does it matter?
DuckDB is an in-process analytical database engine optimized for columnar data. It can execute complex queries on large CSV files far faster than traditional row-by-row parsers.
Is my large file kept private?
Yes. Files are processed in memory for your session only, never stored permanently, and purged when your session ends.