Online CSV, TSV & Delimited File Viewer
Inspect comma-, tab-, pipe-, and semicolon-delimited datasets in a fast virtualized table with automatic delimiter detection and zero server uploads.
Drag & drop files here, or click to browse
Open single or multiple files simultaneously in tabs
🔒 Your files stay on your device. We never upload your files to any server.
Mastering CSV, TSV & Pipe-Delimited Flat Files Without Spreadsheet Corruption
Comma-Separated Values (.csv), Tab-Separated Values (.tsv), and Pipe-Separated Values (.psv) are the universal lingua franca of data engineering, database exports, CRM migrations, and scientific logging. Defined formally by RFC 4180, delimited text files store tabular records as plain text lines where fields are separated by a delimiter character (comma, tab, pipe, or semicolon) and complex strings containing line breaks or delimiters are wrapped in quotation marks.
Ironically, opening a .csv file in traditional desktop spreadsheet software like Microsoft Excel often corrupts the data: leading zeros in ZIP codes or account IDs (such as "00482") are silently stripped, long numeric strings like credit card or tracking numbers are converted into lossy scientific notation (1.23E+15), and date strings like "10-12" are auto-converted into calendar dates. Furthermore, regional settings frequently fail to split semicolon- or pipe-delimited exports properly.
FilePeek solves every one of these frustrations. Using PapaParse in your local browser memory, FilePeek automatically detects whether your file uses commas, tabs, pipes (|), or semicolons (;), preserves exact string representations without mangling leading zeros or long IDs, and renders up to hundreds of thousands of records inside a virtualized, sortable, searchable grid.
Technical Specifications
Architectural details and file format parameters verified by FilePeek.
| Specification | RFC 4180 Compliant + Extended Delimiter Support |
|---|---|
| Supported Extensions | .csv, .tsv, .tab, .psv |
| Auto-Detected Delimiters | Comma (,), Tab (\t), Pipe (|), Semicolon (;) |
| Maximum File Size | 500 MB Local Browser Memory |
| Data Integrity | Zero type-mangling (preserves leading zeros & long IDs) |
| Parser Engine | Client-side PapaParse + Virtualized Viewport Table |
How to Open & View CSV Viewer Files
Step-by-step instructions for viewing files without installing desktop software.
Drop Your .CSV, .TSV, or .PSV File
Drag your delimited file onto the dropzone above or click "Browse Files" to select a dataset from your device.
Automatic Delimiter & Header Recognition
FilePeek analyzes the first lines to auto-detect comma, tab, pipe, or semicolon separators and maps the first row as sticky column headers.
Override Delimiter, Sort & Filter Rows
Switch delimiters manually if needed, click any column header to sort values, or type a search query to filter matching records instantaneously.
Inspect Row & Column Diagnostics
Verify exact row counts, column counts, and character encoding in the toolbar without risking accidental changes to the source file.
CSV Viewer Viewer Features
Modern browser utilities designed for clarity, performance, and privacy.
Automatic & Manual Delimiter Switcher
Automatically detects Comma (,), Tab (\t), Pipe (|), and Semicolon (;) separators with a toolbar dropdown to override at any time.
Zero Data Mangling Guarantee
Displays exact raw text values in every cell—never strips leading zeros from postal codes or converts long IDs into scientific notation.
60fps Virtualized Table Scrolling
Smoothly browse massive database dumps and log exports containing tens of thousands of rows without locking up your browser.
Instant Multi-Column Keyword Filter
Type any substring to filter the entire table in real time and see the exact count of matching rows vs. total rows.
RFC 4180 Quoted Field Handling
Properly parses quoted strings containing embedded commas, escaped quotes, and multi-line text fields.
Header Row Toggle
Toggle whether the first row of the file should be treated as named column headers or as data row #1.
Common Real-World Scenarios
How professionals and casual users rely on FilePeek's local engine daily.
Inspect SQL table dumps, Snowflake/BigQuery exports, and pipe-delimited (.psv) staging files before running production imports.
Audit product catalog CSVs, Shopify/ WooCommerce feeds, and CRM contact lists without Excel corrupting SKUs or phone numbers.
Preview training datasets, Kaggle CSVs, and bioinformatics .tsv matrices rapidly in the browser.
CSV Viewer Frequently Asked Questions
Answers to common questions regarding CSV Viewer rendering and privacy.
Why is FilePeek better than Excel for previewing CSV files?
Excel automatically mutates data types upon opening a CSV—dropping leading zeros (e.g., turning ZIP code 01234 into 1234) and converting long IDs into scientific notation. FilePeek renders exact literal strings in read-only mode so you see your true data.
Can FilePeek open pipe-delimited (|) or semicolon-delimited (;) CSV files?
Yes. FilePeek automatically detects commas, tabs, pipes, and semicolons, and also provides a Delimiter selector in the toolbar so you can switch separators on the fly.
What if my CSV file does not have a header row?
You can toggle the "First row is header" option in the CSV viewer toolbar to switch between named headers from Row 1 and synthetic Column 1, Column 2 labels.
Are my customer lists or database exports uploaded to any server?
Never. All CSV parsing, sorting, and filtering happens 100% locally in your browser memory. Your dataset never leaves your computer.
Can I also open .dat or .txt delimited flat files?
Yes! FilePeek supports .csv, .tsv, .psv, .txt, and .dat flat files, all of which can be inspected either as raw text or as a structured delimiter grid.
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Explore other zero-installation format viewers available on FilePeek.