Large CSV Viewer and Search
Open big CSV files in your browser, sort, filter and search rows quickly, with nothing uploaded.
- Runs in your browser, files never leave your device
- Free, open source, no account, no ads
- Works offline after the first visit
Open and explore a CSV file
Drop a CSV file here or choose a file
CSV, TSV or TXT, even hundreds of thousands of rows. The file is read on this device and never uploaded.
No rows match the search and filters.
Click a cell to see the whole row. / search · arrows move · Esc clears · Ctrl/⌘+C copies the cell
How it works
- Open your CSV. Drop a CSV, TSV or TXT export on the page or pick it. It is parsed in a background worker on your device, with the delimiter, header row and text encoding detected for you.
- Explore the rows. Scroll smoothly through every row, click a header to sort, search all columns, add filters, hide columns and tap a cell to read the full row.
- Keep what you need. Copy a cell or a row, or download the current filtered and sorted view as a new CSV. The original file is never changed.
Questions, answered
Are my files uploaded anywhere?
No. Large CSV Viewer and Search runs entirely in your browser. Your file is read into memory on your device, parsed with JavaScript in a Web Worker, and never sent to a server. You can disconnect from the internet and it keeps working.
How large a CSV file can it open?
There is no row limit, so files with more than a million rows work as long as your device has the memory. Only the rows on screen are drawn, so scrolling stays smooth. A desktop browser usually handles a few hundred megabytes; for files over 300 MB you can open a preview of the first 100,000 rows instead, which is safer on phones.
Why not just open the CSV in Excel?
Spreadsheet apps stop at 1,048,576 rows and often change your data while opening it, for example dropping leading zeros from IDs or turning codes into dates. This viewer shows every value exactly as it is written in the file and never edits it.
Is it really free?
Yes. It is open source under the MIT license, with no account, no row limits and no ads. If it saves you a paid subscription, you can say thanks on Ko-fi.
Does it work offline?
Yes. After your first visit the page is cached by a service worker, so it loads without a connection. You can also install it from your browser's menu as an app.
Was this written by AI?
Yes. Large CSV Viewer and Search was generated by Claude Code from a written specification inside an automated pipeline, with a test suite that runs in a real browser. The full source is on GitHub, so you can read every line before you trust it with your files.
Built by one person, given away for free
Large CSV Viewer and Search is a free alternative to paid tools like ConvertCSV Viewer and Datablist online CSV viewers. If it earns a place in your bookmarks, a coffee keeps the updates coming.
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