jsonl.co

Free online JSONL viewer & editor. Open, search, validate and edit 1GB+ JSONL/NDJSON files right in your browser. No upload, no sign-up, 100% local.

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About

jsonl.co is a free, local-first JSONL viewer and editor. It streams .jsonl, .ndjson and .json files of 1GB+ straight in your browser with syntax highlighting, real-time validation and a side-by-side raw/parsed view. Nothing is uploaded and no account is needed. Includes free converters, a validator and guides.

Features

Large-file JSONL viewer
Streams .jsonl, .ndjson and .json files of 1GB+ in the browser and renders visible rows.
Local-first editor and validator
Shows raw lines beside parsed JSON with syntax highlighting and real-time validation; edit, find and replace lines locally.
Converters and utilities
Includes converters between JSONL, JSON, CSV, Excel and YAML, plus a formatter, validator, splitter, merger and JSON flattener.