Drop a CSV file. Any size.
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.
OmniViewer opens a CSV right in your browser. Drop the file and you get an aligned table with typed cells, an in‑browser SQL engine to query it, one‑click conversion to JSON, per‑column statistics, and of course the raw content with line numbers and a hex view. There is no upload and no server; the page reads only the bytes it needs, so even a multi‑gigabyte export opens instantly and privately.
SELECT…FROM data and query it, no upload"‑quoted fields, CRLF vs LFCSV — comma‑separated values — is the lowest common denominator for tabular data: one record per line, fields separated by a delimiter, with quoting for fields that contain the delimiter, quotes or newlines. It is loosely described by RFC 4180, though real‑world files vary in delimiter (comma, tab, semicolon), quoting and encoding — which is exactly why looking at the raw bytes is useful.
OmniViewer’s table, SQL, JSON and stats work on the first 32 MB of a very large file (the SQL engine streams the whole file); the raw and hex views cover every byte at any size. When you need the full file as a fast, sortable and filterable table — with column resizing and a splitter across tens of gigabytes — the dedicated tool is hugecsv.com, by the same authors, which parses CSV with a WebAssembly engine and has been tested in‑browser with a 21 GB / 100‑million‑row file. OmniViewer opens every file format — and CSV is one it has dedicated tooling for.
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.