How to Parse Large JSON in JavaScript Without Crashing
Strategies for handling massive multi-megabyte JSON files in browser and Node.js without freezing the UI or running out of memory.
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Running `JSON.parse()` on a 50 MB or 100 MB string in client-side JavaScript can freeze the browser main thread or trigger an `Out of Memory` crash.
1. Offload to a Web Worker
By moving `JSON.parse()` into a background Web Worker, the calculation executes on an independent thread, keeping the user interface completely fluid at 60 frames per second.
2. Stream Processing with Oboe.js or Stream-JSON
For gigabyte-scale datasets in Node.js, stream the file line by line using stream-based parsers rather than buffering the entire string into memory.
3. Consider NDJSON (Newline Delimited JSON)
For telemetry and log exports, NDJSON format stores each JSON record on an individual line, allowing consumers to parse records incrementally without constructing a massive global array in memory.
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