Generate random CSV rows or JSON lines for fixtures and tests — pick a format and row count. Seed mock data fast — local generation, free, no signup.
Content reviewed October 2026 · About Toolzum
Generate random times with 24-hour and 12-hour outputs. Schedule surprise drills and test fixtures — free, local, no signup.
Pivot CSV rows into summary tables — group, count, and sum without spreadsheets. Summarize 10k sales rows by region instantly — local pivoting, free, no signup.
Filter CSV rows by column value with case-insensitive contains matching. Keep only the rows you need — local, free, no signup.
Generate realistic mock JSON from field specs — names, emails, dates, nested objects. Fill frontends before backends exist — local generation, free, no signup.
Generate realistic fake datasets — users, orders, addresses — for demos and load tests. Fill staging with 10k believable rows — local generation, free, no signup.
No input conversion here — the tool creates fresh random rows, not conversions. CSV rows carry first name, last name, age, and status; JSON lines carry id, name, age, email, and active flag.
JSON mode emits one object per line (JSON Lines). Wrap lines in brackets with commas to form an array by hand.
CSV mode outputs plain comma rows with no header line. Add headers yourself if the importer needs them.
No — conversion runs locally in your browser. Data never leaves your device.
CSV rows carry first,last,age 20-69,status (Active/Inactive/Pending); JSON lines carry an 8-char id, name, age, lowercase email, and an active flag true about 70% of the time. The slider runs 1-50 rows; CSV mode has no header line.
CSV to NDJSON
Convert CSV rows to newline-delimited JSON for streaming pipelines and log systems. Feed Kafka without reformatting — local conversion, free, no signup.
CSV Output Tools
Format and validate CSV files — consistent delimiters, quoting, and line endings. Fix files Excel mangles on export — local processing, free, no signup.
JSON to CSV
Converts JSON files to CSV format — APIs, configuration files, and data exchange between web services to spreadsheets, database exports, and data imports. All conversion happens locally in your browser with no file size limits.
CSV to JSON
Converts CSV files to JSON format — spreadsheets, database exports, and data imports to APIs, configuration files, and data exchange between web services. All conversion happens locally in your browser with no file size limits.