Edit your CSV in the browser.
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 opens the raw text in a
line-numbered editor: fix a stray value, correct a header,
delete a bad row, and download the edited file when you’re done.
Nothing is uploaded and there is no server — the file stays on your computer.
The editor is backed by a piece table, so it stays responsive on files far larger than a spreadsheet would open, and it exports the exact bytes you edited — no re-quoting, no encoding surprises. Flip to the table, SQL, JSON, stats or hex views on the same drop to check your change did what you meant.
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.