CSV Viewer Online

Open a CSV or TSV file, browse it in a fast table, and search, sort, filter and export it. The file is read by your browser; it is not uploaded.

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What this tool does

A CSV (comma-separated values) file stores tabular data as plain text. This viewer parses that text into a proper table you can actually work with: a fixed header, columns you can sort and resize, and controls to search and filter without opening a spreadsheet program. It is built for CSV files that are inconvenient to open elsewhere, either because they are large or because you just need a quick look.

How it works

The file is handed to DuckDB running as WebAssembly inside your browser, in a background Web Worker so the page stays responsive. Every time you search, sort, filter, turn a page or export, this viewer runs a SQL query against the file and asks only for the rows it needs, instead of loading the whole file into the page. Search and filter values are always passed as query parameters, never inserted into the SQL text.

Browser-local processing

Nothing about opening or querying your file involves a server: the WebAssembly engine, its Parquet and JSON components, and this page's own code are all served from this site, and the browser is told to refuse requests to any other site while the tool runs. See the privacy page for exactly what that does and does not guarantee.

Supported files and limitations

CSV and TSV files are supported, with automatic delimiter, header and column-type detection. Quoted values, commas or newlines inside quoted fields, and UTF-8 (with or without a byte-order mark) are handled. Duplicate column names are kept and automatically renamed so every column stays visible. Rows with the wrong number of fields are a genuinely ambiguous case: the underlying engine makes a best effort, which can mean a malformed row is dropped rather than shown, so a file you know to be irregular is worth spot-checking. This tool does not support every possible CSV dialect, and it does not promise to process files of unlimited size — see the large-file notes below.

Searching, sorting and filtering

The search box matches the text form of any column. Click a column header to sort by it, ascending, then descending, then back to unsorted. Filters let you narrow rows by column: text columns support equals, contains, starts with, ends with, empty and not-empty; numeric columns add greater-than and less-than comparisons. Typing is debounced, so a query only runs once you pause.

Exporting

“Export CSV” downloads the current search, filters and sort order applied to the whole file, not just the current page and not necessarily the original, unfiltered file. Any text value that would be read as a formula by a spreadsheet program (starting with =, +, -, @, a tab or a carriage return) is prefixed with a quote character so it opens as plain text instead.

Large files

Files are read by your device, so performance depends on your browser and its available memory. This tool warns you above roughly 100 MB, warns more strongly above roughly 500 MB, and declines to open a file above roughly 2 GB rather than risk crashing the tab. These are practical guidelines, not a guarantee: a very large or very wide file can still be slow, and there is no such thing as unlimited processing in a browser tab.