Profile your CSV columns.
safe · secure · no server · works offline · fast
…or just start typing at the cursor.
safe · secure · no server · works offline · fast
…or just start typing at the cursor.
Drop a .csv file and OmniViewer builds a per-column
profile: for each column it reports the type mix (numbers,
text, booleans), how many cells are blank, how many distinct values it holds,
and the min and max of the numeric ones. It runs locally in a background Web
Worker — no upload, no server.
Column stats are the fastest way to size up a spreadsheet export before you query, convert or import it: which columns are keys, which are mostly empty, where the outliers are. The same drop also shows the CSV as a table, runs SQL against it, converts it to JSON, and opens raw and hex views.
It’s one lens on OmniViewer’s CSV Viewer — Table, SQL & JSON, Locally: drop a file and every tab is one click away. OmniViewer opens every file format, entirely in your browser — no upload, no server.
No. OmniViewer is a static page with no server-side processing: your CSV is read directly by your browser and never leaves your computer.
CSV (comma-separated values) is a plain-text format for tabular data: one record per line, with fields separated by a delimiter — usually a comma, sometimes a tab or semicolon — and quoting for fields that contain the delimiter, a quote or a newline. It is loosely standardised by RFC 4180.
Effectively unlimited. OmniViewer only reads the bytes needed to paint the screen, so the raw and hex views open a 20 GB CSV as readily as a 2 KB one; the engine behind them has been tested in-browser with a 40 GB file.
Yes. OmniViewer shows a formatted, column-aligned table, converts the CSV to JSON, computes per-column statistics, and runs SQL against it with an in-browser SQLite engine (write SELECT … FROM data). The table, JSON and stats work on the first 32 MB of a very large file; the SQL engine streams the whole file. For the full file as a sortable, filterable table with column resizing and splitting across tens of gigabytes, use hugecsv.com (tested with a 21 GB, 100-million-row file).
The hex view shows the exact bytes, so you can see whether fields are separated by commas, tabs or semicolons, whether lines end in CRLF or LF, and whether there is a byte-order mark. OmniViewer detects text vs binary from the content, not the extension.
Same engine, same authors. OmniViewer is the universal front door for any file, with a CSV toolkit — table, SQL, JSON and stats — for everyday files. hugecsv.com is the specialised workbench for very large CSV files, with a WebAssembly parser, full-file sortable/filterable tables, column resizing and splitting across tens of gigabytes.