Hi Product Hunt! I’m the maker of BigLeaf, a free, read-only JSON, JSONL, and NDJSON viewer for Mac. BigLeaf is built for inspecting large logs, database exports, and API dumps. It uses memory mapping and a sparse index instead of loading the entire file into RAM. In an Apple Silicon benchmark, a 21.5GB JSONL used about 69MB of RAM. Scroll through records on the left and expand the selected record as a tree on the right. Search the whole file with literal substring matching, filter down to matching records, jump to a record number, and copy values, key paths, raw lines, or formatted records. Lines that aren’t valid JSON remain visible as raw records. Root-array JSON is supported too. Your files never leave your Mac, and BigLeaf opens them read-only. No accounts, analytics, telemetry, or cloud uploads. Version 1.2.0 removes the old 100MB limit. Every feature is free at any file size. The optional Tip Jar supports development and unlocks nothing. Requires macOS 14 or later; supports Apple Silicon and Intel Macs. I’d love to hear what kinds of large JSON or JSONL files you need to inspect, and which parts of that workflow are hardest today.

BigLeaf

Read huge JSON and JSONL files locally on your Mac

Read huge JSON and JSONL files locally on your Mac