JSON vs JSONL: Which to Use?
Both formats store structured data, but they have very different performance characteristics for large datasets.
Quick comparison
| Feature | JSON | JSONL |
|---|---|---|
| Structure | Single array | One object per line |
| Streaming | Hard | Easy |
| Append | Requires rewrite | Just add line |
| Large files | Memory issues | Works great |
When to use JSON
- Small datasets (< 100MB)
- APIs that require a single response object
- Configuration files
When to use JSONL
- Log files and event streams
- Data that grows over time
- Files larger than 100MB
- Data that needs to be processed line-by-line