Large CSV to JSON: Streaming and Chunked Reads
Convert large CSV files to JSON without running out of memory. Use streaming parsers, chunked reads, and NDJSON output for multi-GB files.
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Tags: data, csv, performance
Large CSV to JSON: Streaming, Chunking, and Memory-Safe Conversion Loading a 500 MB CSV into memory and converting it to a JSON array in one shot will get you a process killed signal or an out-of-memory error. The fix is streaming — processing data row by row without ever holding the full dataset in memory. This guide covers the right approach for every runtime: browser, Node.js, and Python. --- Why Large Files Break Naive Approaches A 100 MB CSV file might become a 250 MB JSON array after conversion. Load both into memory simultaneously and you're at 350 MB before doing any work. Add garbage collection, string interning overhead, and V8 or CPython's memory fragmentation — and a "100 MB file" can easily consume 1–2 GB of heap. The solution is streaming: read the input in chunks, process…
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