Convert NDJSON to CSV Online - Free, Local & Instant
Instant NDJSON (.ndjson) to CSV (.csv) converter. 100% client-side processing in your browser RAM — zero file uploads, full privacy, drag & drop or paste raw text.
Technical Comparison: NDJSON vs CSV
Data & Dev Config| Specification | NDJSON (Source) | CSV (Target) |
|---|---|---|
| Full Specification | Newline-Delimited JSON (JSON Lines / JSONL) | Comma-Separated Values (RFC 4180) |
| File Extension & MIME | .ndjson (application/x-ndjson) | .csv (text/csv) |
| Data Typing Model | One self-contained JSON record per line | Flat text columns (auto-inferred numbers & booleans) |
| Structure & Hierarchy | Streamable sequence of structured JSON objects | 2D tabular rows (nested keys flattened via dot-notation) |
| Comments Support | None | None |
| Primary Ecosystem | BigQuery imports, LLM fine-tuning datasets, Logstash/Elastic streams | Excel, Google Sheets, pandas DataFrames, BI & analytics imports |
NDJSON to CSV — Before & After Example
{"id":1,"name":"Alice Johnson","email":"alice@example.com","role":"admin","active":true,"score":98.5,"address":{"city":"Berlin","country":"DE"}}
{"id":2,"name":"Bob Smith","email":"bob@example.com","role":"editor","active":false,"score":87,"address":{"city":"Austin","country":"US"}}
{"id":3,"name":"Chiara Rossi","email":"chiara@example.com","role":"viewer","active":true,"score":91.25,"address":{"city":"Milan","country":"IT"}}
id,name,email,role,active,score,address.city,address.country 1,Alice Johnson,alice@example.com,admin,true,98.5,Berlin,DE 2,Bob Smith,bob@example.com,editor,false,87,Austin,US 3,Chiara Rossi,chiara@example.com,viewer,true,91.25,Milan,IT
Frequently Asked Questions: NDJSON to CSV
How do I convert NDJSON to CSV online without uploading sensitive files? ▾
Paste your NDJSON data or drag and drop a .ndjson file into the converter above. ZeroUpload parses NDJSON and serializes CSV 100% inside your browser RAM using local JavaScript—no bytes are ever sent to an external server.
How are nested objects or tabular columns mapped between NDJSON and CSV? ▾
When converting hierarchical structures (Streamable sequence of structured JSON objects) and tabular or config formats (2D tabular rows (nested keys flattened via dot-notation)), our engine automatically flattens or unflattens dot-separated keys (such as address.city) and preserves numbers, booleans, arrays, and null values.
Is this NDJSON to CSV converter free for commercial and production config files? ▾
Yes. The tool is completely free, requires no account or API key, and works offline once loaded. Because execution happens in local memory, it is safe for proprietary NDJSON, database exports, and production secrets.
Can I convert CSV back to NDJSON? ▾
Yes! Click the "Swap (CSV → NDJSON)" button at the top of the workspace or use the reverse converter link at the bottom of this page for bidirectional conversion.