What Is a CSV File?
CSV stands for Comma-Separated Values — a plain-text format for storing tabular data where each line represents a row and each value is separated from the next by a delimiter character, most commonly a comma. CSV is one of the most universal data exchange formats: every spreadsheet application (Excel, Google Sheets, LibreOffice Calc), database, data pipeline, and programming language can read and write it without conversion.
Despite the "comma" in the name, CSV files frequently use other delimiters. Tab-separated files (TSV) are common in bioinformatics and data science exports. European locales often use a semicolon because the comma is reserved as the decimal separator. Pipe-delimited files appear in legacy systems and ETL pipelines. This viewer auto-detects all of them.
How to Use the Online CSV Viewer
Three ways to load your data:
- Paste — copy CSV text from any source and paste it directly into the textarea.
- Upload — click Upload CSV to open a file picker, or drag and drop a
.csvor.tsvfile onto the textarea. - Type — enter data manually for quick exploration.
Once your data is in the textarea, choose your options and click View Table.
Sorting Columns
Click any column header to sort the table by that column. Click again to reverse the order. Sorting is smart: columns containing only numbers are sorted numerically; mixed or text columns use locale-aware string comparison so accented characters sort correctly.
Searching and Filtering
The search box above the table filters rows in real time — any row containing the search term in any column remains visible. Search is case-insensitive. The row counter updates to reflect how many rows match the current query.
Understanding CSV Delimiters
The Auto mode counts occurrences of each candidate delimiter character in the first 3,000 characters of the input (outside of quoted fields) and picks the one that appears most frequently. This works reliably for well-formed files. If auto-detection picks the wrong delimiter — for instance when a file contains occasional pipe characters but is actually comma-separated — override it manually using the delimiter buttons.
Comma vs Tab vs Semicolon
- Comma ( , ) — standard for most exports from web apps, databases and APIs.
- Tab ( \t ) — common in academic data, bioinformatics (BED, GFF, BLAST), and Excel "Save as Text (Tab-delimited)" exports. Values are allowed to contain commas without quoting.
- Semicolon ( ; ) — default in Microsoft Excel installations set to European locales where the comma is the decimal separator (Germany, France, Spain, etc.).
- Pipe ( | ) — used in legacy databases, mainframe exports, and some ETL pipelines. Values rarely contain pipe characters, so quoting is less common.
Quoted Fields
The parser follows RFC 4180: fields that contain the delimiter character, a double-quote, or a newline must be enclosed in double-quote characters. A literal double-quote inside a quoted field is represented as two consecutive double-quotes (""). This correctly handles multi-line cell values and fields that contain the separator character.
Common CSV Viewer Use Cases
- Database exports — quickly inspect rows returned by a SQL query without opening Excel.
- API payloads — some REST and GraphQL APIs return CSV for bulk data endpoints. Preview the payload instantly.
- Spreadsheet data — copy a range from Google Sheets or Excel, paste it here to view and search without the full spreadsheet application.
- Log files — structured log files often use comma or tab delimiters. View and filter specific columns without grep.
- Configuration files — feature flags, routing tables and lookup tables are sometimes maintained as CSV. Visualize them as a table for easier review.
Examples
Standard CSV
name,age,city
Alice,30,Paris
Bob,25,"New York"
Carol,28,LondonComma delimiter, first row as header. The quoted field "New York" is parsed correctly.
TSV Export
id product price
1 Widget A 9.99
2 Widget B 14.50
3 Widget, Pro 24.00Tab-separated values. The product name Widget, Pro contains a comma but needs no quoting because the delimiter is a tab.
European Semicolon
nom;prix;quantité
Produit A;1,99;100
Produit B;14,50;25Semicolon delimiter (common in French/German Excel exports). Prices use a comma as decimal separator — no conflict with the delimiter.
Frequently Asked Questions
No. All parsing and rendering happens entirely in your browser using JavaScript. Your data never leaves your device. You can disconnect from the internet after the page loads and the tool will still work.
The tool samples the first 3,000 characters of your input and counts occurrences of each candidate delimiter (comma, tab, semicolon, pipe) outside of quoted fields. The character that appears most frequently is selected as the delimiter. If auto-detection is wrong, override it by clicking one of the delimiter buttons.
Yes. Upload a .tsv file or paste tab-separated content and select Tab as the delimiter (or leave it on Auto — the auto-detector recognises tab-separated files reliably). TSV is fully supported including quoted fields.
Yes. The parser follows RFC 4180: any field that contains the delimiter, a double-quote, or a newline must be enclosed in double-quote characters. A literal double-quote is represented as two consecutive double-quotes (""). All of these cases are handled correctly.
Click any column header in the rendered table to sort by that column in ascending order. Click the same header again to reverse the sort to descending. Columns that contain only numeric values are sorted numerically; all other columns use locale-aware string comparison.
The tool displays up to 5,000 rows to keep rendering fast. The underlying data is still fully loaded and searchable — only the table display is capped. For files beyond that limit, a note is shown with the total row count. Files are limited only by your browser's available memory; typical CSV files up to tens of megabytes load in well under a second.
Yes. Click Download CSV in the toolbar above the table to export the currently visible rows (respecting any active sort and search filter) as a properly quoted RFC 4180 CSV file.
Uncheck First row as header before clicking View Table. The tool will auto-generate column names (Col 1, Col 2, …) so you can still sort and search without treating the first data row as headers.