A single command-line toolbox for the data wrangling tasks analysts hit every day — format conversion, splitting, merging, validation and sampling — running fully offline so confidential operational and financial data never reaches a third-party server.
Data files from real systems are large, inconsistently encoded and often confidential. Generic web tools are built for small, clean samples.
Online converters cap file size and require the upload, which is a compliance problem when the CSV contains customer records, transactions or employee data.
Naive split tools divide rows but drop or repeat the header on every shard, forcing manual cleanup before each chunk can be opened or imported.
JSONL with one bad line or a CSV whose column count drifts midway often passes conversion and fails much later, inside the database import.
The high-frequency operations data, ops and finance teams run on exported files, packaged into one local toolbox.
Convert CSV/Excel exports to JSON or JSONL using the header row as field names, and reverse JSON arrays back into clean CSV.
Split oversized CSV by row count while preserving the header on every shard, sized for upload limits or parallel processing.
Recombine multiple split files back into one consistent dataset with a single command.
Check column-count consistency across rows and validate JSON/JSONL legality, producing a report that flags the exact bad lines.
Pull random or first-N rows to inspect a huge file quickly without opening the entire dataset in a spreadsheet.
Handles the UTF-8 BOM that Excel exports add and runs with no external dependencies, file in and file out.
Point the toolbox at a CSV, JSON or JSONL export on your local machine; nothing is uploaded.
Choose convert, split, merge, validate or sample with a single explicit command.
Processing happens locally with no dependencies or API calls, even on very large files.
Get consistently headed shards, validated JSON or a sample ready for import, analysis or sharing.
| Capability | This local tool | Typical online service |
|---|---|---|
| Files uploaded to a server | Never — fully offline | Yes, required |
| Header preserved on every split shard | Guaranteed | Often missing |
| JSON/CSV validation report | Built in | Rarely offered |
| File size limits | Local, bounded by disk | Strict web caps |
| API key or subscription | None, one-time | Account required |
No. The toolbox runs entirely on your local computer as a command-line utility with no network calls, so sensitive CSV and JSON data never leaves your machine.
Yes. It detects and handles the UTF-8 byte-order mark that Excel adds, so the first column name is read correctly instead of carrying hidden characters.
When you split a CSV by row count, every output shard automatically repeats the original header row, so each chunk opens and imports correctly on its own.
It verifies that every CSV row has the expected number of columns and that JSON/JSONL content is legal, then reports the specific lines that fail instead of failing silently at import time.
No external dependencies and no API key. It runs with a local runtime and a single command, file in and file out.
Get the local toolbox that converts, splits, merges, validates and samples your data files without uploads, subscriptions or per-file limits. One-time download.