Drop in a file that’s too big for Excel or Google Sheets. openbigcsv.com parses it in your browser, keeps it off any server, and lets you search, sort, and export it in seconds.
Free, no install, no account — however many files you open. For tens of millions of rows and warehouse data, that’s Row Zero.
Drop a CSV file here
Read on this device. Nothing uploaded anywhere.
Millions
rows, free, in this browser tool
10s of millions
rows on Row Zero's free plan
1 billion+
rows on Row Zero Enterprise
0
bytes of your file sent to a server
How it works
Excel tops out around 1,048,576 rows and slows down long before that. Google Sheets caps at 10 million cells. openbigcsv.com skips both limits by never loading the whole file into a spreadsheet grid at once.
Drop in your file
Drag a CSV file onto the page, or click to browse. Parsing starts immediately, streamed in chunks. It is read and parsed on your machine with a background worker thread — no upload, no server round-trip, no copy of your data anywhere.
Search, sort, explore
Type into the search box to filter every column at once, or click a column header to sort by it. The grid renders only a window of visible rows and swaps them as you scroll, so 250,000 rows scroll as smoothly as 250.
Export, or move to Row Zero
Download the filtered view as CSV, or continue the same file in Row Zero for pivot tables, charts, and tens of millions of rows. You export exactly the rows you are looking at, as a clean CSV.
When you outgrow a browser tab
openbigcsv.com is built by Row Zero, a cloud spreadsheet that connects live to Snowflake, Databricks, Redshift, and BigQuery and handles billion-row datasets without exporting ungoverned CSVs in the first place.
Open the same file, further
Row Zero's free plan opens 10s of millions of rows, keeps hundreds of Excel-compatible functions, and includes pivot tables and charts.
Skip the CSV export entirely
Connect straight to your warehouse instead of exporting a file at all — every CSV export is a copy of your data that someone now has to secure.
Enterprise-ready when you need it
SOC 2 Type II, HIPAA, and GDPR compliant, with a Zero Data Retention architecture and support for 1 billion+ row datasets on Enterprise.
FAQ
No. The file is read and parsed entirely inside your browser using a Web Worker. openbigcsv.com does not upload, store, or log the contents of your file.
The page itself needs to load once from the internet, but once loaded, parsing a file does not require a network request — your file never goes anywhere.
Those need a spreadsheet engine, so they hand your data to Row Zero. If you opened the file from a URL, Row Zero fetches that same URL itself and nothing is copied. If you opened a local file, the rows currently in view are copied to your clipboard to paste in — or, when there are too many to paste, downloaded as a CSV you drop in. Either way the data moves only because you clicked, and it never passes through a server of ours. There isn't one.
Millions, depending on your device's available memory and the number of columns — the limit is what your browser tab can hold rather than a fixed row count, so a narrow file goes further than a wide one. If a file exceeds it, the viewer loads as much as it safely can and tells you exactly how much it skipped. For files in the tens of millions of rows and beyond, use Row Zero, which is free to start and connects directly to data warehouses.
CSV, TSV, and plain delimited TXT files with a header row; the delimiter is detected automatically. You can open a file from your machine or paste the URL of one. For Excel (XLSX), Parquet, or JSONL files, or for a live connection to a data warehouse, use Row Zero.
Excel worksheets are limited to 1,048,576 rows, and performance degrades well before that as formulas and formatting recalculate across the full grid. Google Sheets limits a spreadsheet to 10 million cells total across all sheets. A file bigger than that — or just large in file size — can slow down or crash both applications.
This tool is read-and-export only: search, sort, and export a filtered subset, but no in-place cell editing. For editing, formulas, and saved workbooks, open the file in Row Zero instead.
No. Opening, searching, sorting, and exporting a file on openbigcsv.com does not require an account. An account is only needed if you continue the same file in Row Zero.
Yes. openbigcsv.com is built and operated by Row Zero, Inc., the company behind the Row Zero spreadsheet. The free viewer here solves one narrow problem — opening a big file quickly — while Row Zero is the full connected-spreadsheet product, which is free to start.
Guides
The whole process, start to finish, plus when a browser viewer is the wrong tool for the job.
What Excel's real limits are, why it slows down long before it hits them, and three ways to open the file anyway.
Excel, Google Sheets, this viewer, and Row Zero side by side — where each one actually stops working.