Streaming JSON Parsing

Instead of reading an entire JSON file before processing any of it, streaming parsers emit events as they encounter tokens — allowing you to process records one at a time with bounded memory usage. Libraries like clarinet (Node.js) and ijson (Python) enable processing arbitrarily large JSON arrays.

JSON Lines Format

JSON Lines (JSONL) stores one complete JSON object per line rather than wrapping everything in a single array. This format is ideal for large datasets because each line is independently parseable. You can process line by line with a simple file reader and parallelize processing easily.

Command-Line Tools for Large JSON

The jq command-line tool is essential for working with large JSON files in the terminal. It supports filtering, transformation, and extraction using a powerful query language, processing data in streaming mode with bounded memory. It handles multi-gigabyte JSON that would crash a GUI tool.

Browser Limitations for Large JSON

Browsers have strict memory limits. Parsing a 100MB JSON file in a browser tab will likely crash it. For large data files on the web, prefer paginated APIs that return manageable chunks or server-side preprocessing to extract the relevant subset.

Key Takeaway

Large JSON requires streaming parsers, JSON Lines format, or pagination strategies. Never load multi-megabyte JSON into browser memory — design APIs to return appropriately sized responses.