Private, local-first data tools
Open, search and export CSV files without uploading them. Tested with a 1 GB file and over two million records.
Search and export complete CSV files. 1 GB tested. Choose a file or try the example.
Choose a local CSV to begin.
Export writes UTF-8, comma-delimited CSV with a header. A native save dialog is used where supported; otherwise a temporary file is written in private browser storage until you reset or export again. Cleanup on leaving is best-effort; interrupted tabs may leave temporary output in browser storage. Disk space and browser quotas still apply.
1 GB CSV processing is verified in desktop Chromium. Larger files are not blocked by a fixed size cap, but have not been validated. Actual capacity depends on the browser and available disk space. Individual records are limited to 256 Ki characters and 4,096 columns. Malformed quotes, decoding errors and inconsistent columns block export. Choose Paste, sort & convert for sorting, repair, JSON and Excel conversion of smaller datasets.
The parser runs off the main thread. Once loaded, you can search, sort, validate, repair and export without an account.
Need another workflow? Use the CSV file merger to combine exports, the CSV splitter for smaller batches, or the CSV to Excel converter to create a workbook.
| Task | Open & search · large files | Paste, sort & convert |
|---|---|---|
| Input | Local CSV, TSV or TXT; select the separator and encoding | Local files, pasted data or a public URL that permits CORS; automatic detection available |
| Search and order | Search the full source; keep source order | Search and sort the retained dataset |
| Download | All matching records and columns as CSV | CSV, JSON or XLSX; choose search results or all retained rows |
| Boundary | 1 GiB synthetic file verified; record width, storage and browser limits still apply | 250,000 retained rows; incomplete data cannot be exported |
For example, use the large-file mode to find an account ID in a two-million-record export. Search matches a case-insensitive substring inside any single cell; it is not a regular expression or an exact-key comparison. Check the match count and download all matches, even when the preview shows only the first page.
To sort that data or convert it to JSON or Excel, switch to Paste, sort & convert and load a file there separately. Switching modes does not transfer the loaded file. If it exceeds the standard limit, prepare a smaller export at the source; the CSV splitter also has its own 25 MB and 250,000-record input limits.
What this tool does
The streaming viewer reads local CSV and TSV files in 256 KiB chunks, validates every record and searches the full source. It keeps only a bounded page in memory and writes complete CSV exports to disk. Choose Paste, sort & convert for automatic detection, sorting, repair and format conversion of smaller retained datasets.
Local files are read by a dedicated browser worker and are not uploaded to an application server. File contents and filenames are not included in analytics events. Loading a public URL is an explicit direct request from your browser and may fail when the remote server blocks CORS.
No. Local files are passed directly to a browser worker. The application does not send file contents or filenames to an application server.
Yes. Select comma, tab, semicolon or pipe in streaming mode. Automatic detection is also available in the standard workbench.
Yes. The default large-file viewer searches the full file and exports CSV in source order. For sorting or JSON/XLSX output, choose Paste, sort & convert and load the file there separately; that workspace retains up to 250,000 rows.
That limit applies to the standard workbench. Open the original local CSV in the streaming viewer at the top of this page to search and export beyond 250,000 rows. Malformed records and unavailable disk storage still block export.